Dialysis system for the treatment of sepsis

Abstract

The present invention relates to the field of medical devices, more particularly to the field of devices for extracting circulating molecules from the blood of a mammal, and their therapeutic uses, in particular in the treatment of sepsis, cytokine release syndrome and / or any other form of systemic inflammatory response or cytokine shock, caused by bacterial, parasitic, fungal or viral infections, in particular caused by a viral infection, for example coronaviruses with human respiratory tropism.

Description

Title of the invention: Dialysis system for the treatment of sepsis Technical field

[0001] The present invention relates to the field of medical devices, more particularly the field of devices for extracting circulating molecules from the blood of a mammal, and their therapeutic uses, in particular in the treatment of sepsis, cytokine release syndrome and / or any other form of systemic inflammatory response or cytokine shock, caused by bacterial, parasitic, fungal or viral infections, in particular caused by a viral infection, for example coronaviruses with human respiratory tropism. Context

[0002] Severe acute respiratory coronavirus 2 (SARS-CoV-2) first appeared in Wuhan, China, in late 2019. Although the majority of patients have a relatively good prognosis, COVID-19 carries a significant mortality rate, for example, close to 3.7% in some studies1. For critically ill and deceased patients, generally no serious manifestations are observed at the onset of the disease (only a mild fever, cough, or muscle aches).

[0003] However, the condition of patients deteriorates rapidly at an advanced stage of the disease. Different syndromes are associated with the severity of the disease: (i) acute respiratory distress syndrome (ARDS), (ii) multiple organ failure, (iii) sepsis and septic shock2,3.

[0004] In the recent past, coronaviruses have caused other respiratory diseases, namely Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS)4.

[0005] Clinical manifestations, including fever, non-productive cough, dyspnea, myalgia, fatigue, radiographic evidence of pneumonia, etc., are similar to the symptoms of SARS and MERS.

[0006] ARDS is the common immunopathological event for COVID-19, SARS, and MERS, and the leading cause of death in COVID-195.

[0007] ARDS occurs most commonly in the elderly and those with immune disorders and comorbidities. Pneumonia syndrome may also be associated with bacterial coinfection in severe cases and sepsis6.

[0008] Cytokine storm, also known as cytokine storm, is considered one of the main causes of ARDS and multiple organ failure, and plays an important role in the process of disease progression.

[0009] Cytokine storm is the uncontrolled and fatal systemic inflammatory response resulting from the release of large amounts of pro-inflammatory cytokines (e.g. IFN-a, IFN-y, IL-1[3, IL-6, IL-12, IL-18, IL-33, TNF-a, TGF[3) and chemokines (e.g. CCL2, CCL3, CCL5, CXCL8, CXCL9, CXCL10).

[0010] Similar to MERS and SARS, individuals with COVID-19 may have elevated serum levels of IL-6, IFN-a, IFN-y, and CCL5, CXCL8, CXCL10 compared to those with mild / moderate disease7,8.

[0011] Clinical predictors of COVID-19 mortality were determined from the study of 150 cases in Wuhan, China. These predictors are elevated ferritin (mean 1297.6 ng / mL in non-survivors vs. 614.0 ng / mL in survivors (p < 0.001)) and elevated IL-6 (p < 0.0001), suggesting that mortality is due to viral-induced hyper-inflammation9.

[0012] These results were confirmed by a meta-analysis showing higher levels of IL-6 (4.6 pg / mL vs. 1.7 pg / mL) and serum ferritin (760.2 ng / mL vs. 408.3 ng / mL) for survivors versus non-survivors of COVID-1910. These data and the elevated IL-10 level observed in severe disease are predictors of cytokine storm syndrome and highlight the role of inflammatory cytokines and iron in the development of severe cases of the disease. The authors thus suggest using IL-6 and ferritin levels as predictors to monitor disease prognosis in patients with COVID-19.

[0013] Blood purification therapy has already shown its potential to eliminate pathogenic antibodies or cytokines in multiple pathologies and may be an interesting therapeutic means for COVID-19 patients11.

[0014] Sepsis is now defined as "a life-threatening organ dysfunction secondary to dysregulation of the host response to infection (bacterial, viral, fungal or parasitic)" (Sepsis-3 Consensus Conference, 2016). Septic shock is defined as "a subgroup of sepsis characterized by intense circulatory, metabolic and cellular abnormalities associated with higher mortality than in Sepsis." The emphasis is on organ dysfunction. The complex pathophysiology combines, in response to microbial invasion: inflammation and immunosuppression, a procoagulant state, endothelial dysfunction and tissue hypoxia: all of these mechanisms ultimately leading to organ failure.

[0015] Standard therapy in early management consists of initiating broad-spectrum antibiotic therapy, identifying the causative agent(s), monitoring the patients' hemodynamic parameters, establishing pulmonary ventilation and administering volume-filling fluids and vasopressor medication with the aim of to maintain satisfactory mean arterial pressure (MAP). Despite the implementation of these aggressive and expensive therapies, short-term and long-term mortality from septic shock remains high and the incidence of the disease is constantly increasing. The prognosis is particularly poor. Mortality due to sepsis is estimated at 25.8% in intensive care units and 35.3% in hospitals12.

[0016] Worldwide, it is estimated that 20 to 30 million people suffer from sepsis each year and that nearly 24,000 people die from it each day. The severity of sepsis is notably due to an activation cascade leading to a self-amplified production of cytokines (cytokine storm) which are relatively small proteins (less than 40 kDa)13.

[0017] Due to the central role of cytokine productions during sepsis and subsequent organ damage, blood purification has been proposed to treat sepsis, mainly using the so-called high-volume hemofiltration technology and / or the so-called adsorbent technology14.

[0018] Adsorbent technology essentially consists of passing blood through an adsorbent material, for example specific membranes or polymer beads, in order to retain excess molecules produced. A well-known example is the commercial device CytoSorb©. These systems, although capable of extracting molecules from the blood, are not specific to a particular type of molecule.

[0019] Similarly, in high-volume hemofiltration, most experimental and clinical studies reporting beneficial effects in inflammatory shocks have been carried out with very high filtration rates, often greater than 100 ml.kg *.h 1, causing a large loss of plasma for the patient, replaced by a replacement liquid reinjected into the extrarenal purification circuit. While it is relatively easy to compensate for the losses of water, salt and some simple chemical elements by the replacement liquid of appropriate electrolytic composition, it is very difficult to compensate for all the essential elements also lost during the high-volume hemofiltration session.

[0020] Different mechanisms have been proposed to show the benefits of reducing cytokine levels in the blood: (i) the peak concentration theory postulating that the elimination of the cytokine peak during the early phase could stop the inflammatory cascade15, (ii) the cytokinetic theory suggesting that the elimination of cytokines from the blood can create a cytokine gradient between the blood flow and tissues and thus, lead to the elimination of cytokines from the tissues due to the balance of cytokine concentration between the tissues and the blood flow.

[0021] However, the main disadvantage of current blood purification methods is the non-specific elimination of certain molecules, for example small blood proteins such as other anti-inflammatory regulatory cytokines. To date, none of the purification methods using an absorbent on beads, porous supports or on membranes is sufficiently specific for a type of molecule. In addition, clinical trials with adsorbent technology are often inconclusive or inconclusive.

[0022] Oxidative stress is a harmful situation for the body that causes biological damage. It occurs when the amount of pro-oxidant molecules is greater than that of antioxidants. Pro-oxidant molecules are mainly composed of reactive oxygen species (ROS) and reactive nitrogen species (RNS). In sepsis conditions, an overproduction of ROS and RNS is observed both in the bloodstream and in damaged organs16.

[0023] It has long been known that ROS production is catalyzed by free iron during the Fenton and Habber-Weis reaction17. There is also evidence that copper is involved in ROS production due to a Fenton-type reaction18. The increase in free or weakly associated copper or free iron (or redox-active transition metals) is directly associated with a significant increase in ROS production and resulting damage.

[0024] Increased serum free iron was recently associated with increased mortality in patients with sepsis in a retrospective study of 1891 patients19. Thus, a higher iron quartile was associated with a significant increase in the risk of 90-day mortality. More importantly, an iron-dependent increase in the risk of death was found as iron levels increased. This study is in agreement with others that associate sepsis with elevated levels of different metals in patients20. In this study, Cr (p < 0.001), Fe (p = 0.004), Ni (p = 0.001), Cu (p < 0.001), and Cd (p < 0.0001) were significantly higher in the serum of the sepsis group than in the control group.

[0025] Due to its importance for bacterial growth and its involvement in ROS production, therapeutic iron restriction has already been proposed as a strategy to treat sepsis and septic shock21. However, despite some success, iron chelation has some limitations, including significant side effects, such as kidney damage or exacerbation of infections for deferoxamine (DFO) which can act as a siderophore for some microorganisms22.

[0026] Although knowledge to treat the aforementioned diseases is evolving, there is currently no effective treatment for sepsis, acute respiratory distress syndrome (ARDS), septic shock, cytokine shock and systemic inflammatory responses, or macrophage activation syndrome (MAS) also called hemophagocytic lymphohistocytosis (HLH), whether or not these diseases are caused by a viral infection, such as for example a coronavirus infection such as COVID-19. The COVID-19 condition linked to SARS-CoV-2 particularly reflects the pathophysiology of sepsis and illustrates the need to implement blood purification therapies. Technical problem

[0027] There is therefore currently a need to develop new means for treating the diseases mentioned above, said means allowing in particular the extraction of circulating molecules from the blood of a mammal and not having the disadvantages of known systems, namely a non-specificity of the circulating molecules to be extracted. Summary

[0028] According to a first aspect, there is provided a dialysis system capable of being connected to an extracorporeal blood circulation device comprising: (i) a porous dialysis membrane, and (ii) a reservoir comprising a dialysis fluid, characterized in that the dialysis fluid comprises at least one additive chosen from nanoparticles, polymers and biomolecules, said additive having a size greater than the cut-off threshold of said porous dialysis membrane, and comprises or consists of at least one ligand specific for a molecule circulating in the blood of a mammal.

[0029] The features set out in the following paragraphs may, optionally, be implemented in the dialysis system according to the invention. They may be implemented independently of one another or in combination with one another.

[0030] According to embodiment 1, the dialysis fluid comprises at least one additive comprising or consisting of a ligand specific to the circulating molecules involved in the mechanisms of the immune response, preferably endotoxins, and / or the molecules activating the immune response, and / or the pro-inflammatory cytokines, preferably IL6, IFN-y and TNF-a.

[0031] According to embodiment 2, at least one of said ligands is an antibody, in particular a recombinant monoclonal antibody, a mixture of antibodies, a fragment antibodies binding the antigen, a structural protein or a fusion protein, or even nanoparticles.

[0032] According to embodiment 3, at least one of said ligands is chosen from drugs directed against interleukin-6 (Sirukumab, Olokizumab), interferon y (Emapalumab), TNF-alfa (Etanercept, Infliximab, Adalimumab, Golimumab, Certolizumab), CCL2 (NOX-E36), interleukin-1B (Canakinumab), and mixtures thereof.

[0033] According to embodiment 4, the porous dialysis membrane has a surface area of ​​at least 0.1 m2.

[0034] According to embodiment 5, the additive is chosen from nanoparticles having an average diameter of 3 to 50 nm, for example polysiloxane nanoparticles.

[0035] According to embodiment 6, the additive is chosen from polymers, for example biocompatible polymers such as polysaccharides, or a biomolecule, and said additive has a size greater than 100 kDa, and preferably less than 1200 kDa.

[0036] According to embodiment 7, at least one of the ligands is specific for circulating molecules involved in oxidative stress, in particular is a ligand specific for metal cations circulating in the blood.

[0037] According to embodiment 8, at least one of the ligands is a molecule complexing metal cations chosen from the following complexing molecules: DOTA, DTPA, EDTA, TTHA, EGTA, BAPTA, NOTA, DOTAGA, DFO, DOTAM, NOTAM, DOTP, NOTP, TETA, TETAM, TETP and DTP AB A, their derivatives and / or their mixtures. Preferably, said complexing molecule is capable of complexing trace metals chosen from Cu, Fe, Zn, Mn, Co, Mg, and Ca, preferably Cu, Fe and Zn.

[0038] According to embodiment 9, the dialysis system comprises one or more additives chosen from: - polysaccharides having a mass of at least 100 kDa and less than 2000 kDa, for example in a concentration of 0.1 to 10 g / l in the dialysis fluid, where appropriate, onto which are covalently grafted molecules complexing metal cations, for example in a number proportion of between 50 and 5000, and preferably between 100 and 1000 per polysaccharide, - ligands specific to circulating blood molecules and having a size greater than 100 kDa, preferably in a proportion of between 1 pg / l and 1 g / l in the dialysis fluid, and / or - polysaccharides onto which specific ligands of circulating blood molecules with a size between 10 and 100 kDa, for example in a number proportion of between 0.1 and 100 and preferably between 1 and 10 per polysaccharide.

[0039] Also provided is a dialysis system as defined in the preceding embodiments for use in the prevention and / or treatment of a disease selected from sepsis, acute respiratory distress syndrome (ARDS), cytokine shock, septic shock and / or any other forms of systemic inflammatory response, macrophage activation syndrome (MAS) or hemophagocytic lymphohistocytosis (HLH). Preferably, the dialysis system is used for the treatment of sepsis or cytokine shock caused by a bacterial, parasitic, fungal or viral infection, preferably a viral infection, for example human respiratory tropism coronaviruses, in particular COVID-19.

[0040] It is also proposed according to another aspect the use of a dialysis fluid additive in a dialysis system according to the preceding embodiments, said additive being selected from nanoparticles, polymers or biomolecules, and in that said additive comprises or consists of a ligand specific for a circulating molecule in the blood. Preferably, the ligand is specific for a circulating molecule involved in the mechanisms of an immune response, for example endotoxins, and / or molecules activating the immune response, and / or pro-inflammatory cytokines, for example IL-6, IFN-y and TNF-a.

[0041] According to a preferred embodiment of this aspect, said ligand is an antibody, in particular a recombinant monoclonal antibody, a mixture of antibodies, or even an antibody fragment binding the antigen.

[0042] According to a preferred embodiment of this aspect, the additive is chosen from nanoparticles or polymers comprising a specific ligand of a molecule complexing the metal cations circulating in the blood, in particular an oligometal chosen from Cu, Fe, Zn, Mn, Co, Mg, and Ca, preferably Cu, Fe and Zn.

[0043] According to a preferred embodiment of this aspect, the additive has a size of from 100 to 1200 kDa.

[0044] A dialysis fluid is also provided, for use in a dialysis system according to the preceding embodiments, characterized in that it comprises an additive as defined above, in an effective amount of 10 to 100 nanomoles, preferably for a total volume of dialysis fluid of 0.5 to 10 liters.

[0045] According to a preferred embodiment, the dialysis fluid is used for the ex vivo capture of circulating blood molecules.

[0046] According to a preferred embodiment, the dialysis fluid is used for the treatment of sepsis, cytokine release syndrome and / or any other form of systemic inflammatory response or cytokine shock.

[0047] According to a preferred embodiment, the dialysis fluid is used to limit the growth of a pathogen. Description of figures Fig.l

[0048] [Fig.l] shows a dialysis system connected to an extracorporeal circulation device according to a first embodiment. A: peristaltic pump; B: conventional dialyzer; C: dialyzer with porous membrane according to the invention; D: bubble trap; E: peristaltic pump; F: dialysis fluid reservoir. Fig. 2

[0049] [Fig.2] shows a dialysis system connected to an extracorporeal circulation device according to a second embodiment. A: reservoir; B: oxygenator; C and D: peristaltic pumps; E: dialyzer with porous membrane; F: dialysis fluid reservoir. Fig. 3

[0050] [Fig.3] shows a dialysis system connected to an extracorporeal circulation device according to a third embodiment. A: peristaltic pump; B: dialyzer with porous membrane; C: bubble trap; D: peristaltic pump; E: dialysis fluid reservoir; F: conventional dialyzer; G: peristaltic pumps of the dialysate circuit. Detailed description

[0051] The inventors have developed a dialysis system capable of being connected to an extracorporeal blood circulation device, said dialysis system allowing the extraction of circulating molecules from the blood of a mammal, and in a specific manner.

[0052] Dialysis consists of bringing the blood into contact with a sterile liquid (the dialysate) whose composition is close to that of plasma (the liquid which makes up approximately 60% of the blood) through a membrane which serves as a filter. In the context of the present invention, we are interested in dialysis systems via extracorporeal blood circulation.

[0053] For the purposes of the present invention, the term "dialysis system" means devices for purifying blood (hemodialysis, hemofiltration or hemodiafiltration). They generally comprise a dialyzer, comprising an artificial, synthetic membrane, and a reservoir comprising a dialysate or dialysis fluid.

[0054] By way of example, dialysis systems adapted according to the invention are notably presented in figures 1 to 3. In these figures, the dialysis systems are connected to extracorporeal circulation devices, such as for example a dialyzer or a blood oxygenation circuit composed of a reservoir and an oxygenator.

[0055] The term "extracorporeal blood circulation device" means a device for diverting venous blood flow into a circuit located outside the body with a circulation rate of at least 10 ml / min. For example, conventional hemodialysis systems or blood oxygenation devices.

[0056] The term "circulating blood molecules" means all molecules found in circulation in the blood, said molecules being able to be independently in free form or in aggregated or complexed form. By way of example and in a non-exhaustive manner, the circulating molecule may be a peptide, a protein, and in particular a glycoprotein, an immunoglobin, a cytokine, a metal cation, metal complexes or even molecules known to those skilled in the art involved in the immune response mechanisms or even molecules activating the pro-inflammatory immune response.

[0057] The dialysis system allows the extraction of circulating molecules in the blood whose size is lower than the cut-off threshold of the dialysis membrane, and in particular circulating molecules whose size is lower than 100 kDa, 50 kDa which constitutes an interesting threshold for the main protein of human blood plasma albumin (65 kDa), or even of the order of 20 to 30 kDa which is the threshold commonly used for hemo(dia)filtration treatments in renal replacement therapy (RRT).

[0058] The term "ligand" means a molecule or part of a molecule which binds, preferably reversibly, to the circulating molecule in a specific manner. Advantageously, the specific ligand-circulating molecule binding is achieved through forces between molecules, such as ionic bonds, hydrogen bonds, hydrophobic interactions and Van der Waals forces or even variations in entropy linked to the release of solvation molecules during the intimate association between two complementary molecules. Thus, the ligand-circulating molecule interaction is reversible and more or less strong depending on the number and nature of the bonds formed. It can also be very specific. The strength of this interaction is defined by the affinity for the circulating molecule, and can be, for example, linked to the dissociation constant.Preferred examples of ligands include antibodies, artificial protein ligands, recombinant peptides or proteins (eg decoy receptors), or molecules that complex metal cations.

[0059] The term "antibodies" means immunoglobulin molecules and their fragments that bind specifically to an antigen (a circulating molecule in the context of the present invention). The term "antibodies" within the meaning of the present invention thus includes antibodies and their fragments, as well as functional variants. The term "antibodies" also includes bispecific or multispecific antibodies. Natural antibodies are immunoglobulins formed of 4 polypeptide chains, two heavy H and two light L, capable of specifically binding an antigen, also called circulating molecule in the context of the present invention. There are 5 types of antibodies, IgG, IgM, IgD, IgA, IgE. The light chain generally includes 2 domains, a variable domain (VL) and a constant domain (CL). The heavy chain includes a variable domain (VH) and 3 constant domains (CH1, CH2, and CH3). The variable regions of the heavy chain and the light chain determine the specificity of antigen recognition.

[0060] The VH and VL regions further comprise hypervariable regions, the CDR regions designated respectively H-CDR1, H-CDR2 and H-CDR3 for the VH region, and L-CDR1, L-CDR2, and L-CDR3 for the VL region. An antibody can be characterized by the polypeptide sequence of its 6 CDRs or the VH and VL regions.

[0061] For the purposes of the invention, an antibody is specific for a circulating molecule if it can bind an epitope of this circulating molecule. For example, it is capable of binding an epitope of a circulating molecule with a KD of 100nM or less, 100nM or less, 100nM or less, 100pM or less, or 100pM or less.

[0062] The affinity constant of an antibody (or KD) can be measured in vitro using methods well known to those skilled in the art, in particular surface plasmon resonance (SPR) methods such as Biacore® (see for example, Rich RL, Day YS, Morton TA, Myszka DG. High-resolution and highthroughput protocols for measuring drug / human serum albumin interactions using BIACORE®. Anal Biochem. 2001 Sep 15;296(2): 197-207).

[0063] The term "antibody" includes in particular monoclonal antibodies, i.e. an antibody preparation with a unique composition, which in particular has a unique specificity and affinity for a particular epitope.

[0064] The term "antibody" also includes non-natural antibodies modified, for example by mutation, humanization, or deletion of regions non-essential for binding to its antigen, and fusion proteins comprising antibody fragments binding the antigen. Finally, the term "antibody" includes chemically modified antibodies, in particular, in order to increase their molecular weights, for example by pegylation.

[0065] The term “artificial protein ligand” (“scaffold protein” or “engineered protein” in English) means a compound or protein fragments selected for their affinity towards specific circulating molecules. They are generally lighter than antibodies, often easier to produce as well and chemically stable. Advantageously, the artificial protein ligands are less than 50 kDa, preferably less than 30 kDa, and more preferably between 10 and 20 kDa. Such ligands have a good specific surface area. These artificial protein ligands can be chosen from: ABD, Adhiron, Adnectin, Affibody, Affilin, Affimer, Affitin, Alphabody, Anticalin, Armadillo repeat proteins, Atrimer / tetranectin, Avimer / Maxibody, Centyrin, DARPinl.

[0066] “Prevention and / or treatment” means a method aimed at reducing, blocking the progression of, preventing or eliminating one or more symptoms in an individual suffering from a pathology or disease causing this or these symptoms or likely to cause them. For example, in the case of an inflammatory disease, the treatment may consist of reducing, decreasing, blocking the progression of or preventing an excessive inflammatory reaction.

[0067] A first aspect of the invention relates to a dialysis system capable of being connected to an extracorporeal blood circulation device, said system comprising: - a porous dialysis membrane, and - a reservoir comprising a dialysis fluid, characterized in that the dialysis fluid comprises an additive chosen from nanoparticles, polymers and biomolecules, said additive having a size greater than the cut-off threshold of said porous dialysis membrane, and comprises or consists of at least one ligand specific for a molecule circulating in the blood of a mammal.

[0068] By a particular choice of additive and / or ligand, the dialysis system according to the invention makes it possible to extract circulating molecules from the blood in a specific manner.

[0069] According to a particular embodiment, the blood of a mammal is human blood.

[0070] Dialysis systems are devices known to those skilled in the art and comprise a porous dialysis membrane and a reservoir comprising a dialysis fluid. The reservoir may be an external reservoir generally requiring an additional device to circulate the dialysis fluid. This reservoir may be directly included in the dialysis cartridge, the cartridge then constituting its own reservoir.

[0071] The dialysis system according to the invention is capable of being connected to an extracorporeal blood circulation device. Such dialysis fluid reservoir devices are for example described in the work: Extrarenal purification in intensive care (Didier Journois, Frédéruqe Schorgen, 2003, Masson) or for example developed or marketed by the companies Baxter, Fresenius, Dialife, Asahi Kasei, Debiotech, Medtronic, Nipro, Torray, Braun.

[0072] According to another particular embodiment, the porous membrane of the dialysis system is advantageously a semi-permeable membrane.

[0073] According to another particular embodiment, the porous membrane has an exchange surface of at least 0.1 m2. Advantageously, the porous membrane has an exchange surface area of ​​0.1 to 4 m2, preferably 0.1 to 3 m2 and more preferably 0.5 to 2.5 m2.

[0074] In the dialysis system according to the invention, the dialysis fluid comprises an additive chosen from nanoparticles, polymers and biomolecules, said additive having a size greater than the cut-off threshold of said porous dialysis membrane, and comprises or consists of at least one ligand specific for a molecule circulating in the blood of a mammal.

[0075] By "cutoff threshold" is meant the critical molar mass for which at least 90% of the solutes are retained by the membrane during a conventional treatment. Thus, in a preferred embodiment, the additive has a critical size that does not allow it to pass through the dialysis membrane. Consequently, the additive or a proportion at least greater than 90% of this additive remains within the dialysis fluid on only one side of the dialysis membrane. And preferably, the cutoff threshold is chosen so that the additive is retained at more than 92%, 94%, 96%, 98% 99%, or even more than 99.9% in the dialysis fluid.

[0076] According to a particular embodiment, the additive has a size greater than 30, 40, 50, 60, 70, 80, 90 or 100 kDa. Preferably, the additive has a size greater than 100 kDa and less than 3000 kDa, more preferably greater than 100 kDa and less than 2000 kDa, and most preferably greater than 100 kDa and less than 1200 kDa.

[0077] In one embodiment, which can be combined with the previous embodiment, the dialysis membrane has a cut-off threshold of less than or equal to 30, 40, 50, 60, 70, 80, 90 or 100 kDa. Preferably, the cut-off threshold is between 5 and 100 kDa, more preferably from 5 to 50 kDa, more preferably from 10 to 30 kDa, and very particularly from 10 to 20 kDa.

[0078] According to a particular embodiment, the difference between the size of the additive and the size of the cut-off threshold is at least 50 kDa and preferably greater than 100 kDa.

[0079] The size of the additive can also be defined by its average diameter, in particular in the case of substantially spherical or globular structures, for example nanoparticles. The term "average diameter" then means the harmonic mean of the diameters of the additive, in particular nanoparticles, of the polymer or of the biomolecule comprising or consisting of a specific ligand of a circulating molecule in the blood.

[0080] The size distribution of nanoparticles or polymers can for example be measured using a commercial granulometer, such as a Malvern Zeta Sizer Nano-S granulometer based on PCS (acronym for "Photon Correlation Spectroscopy") which is characterized by an average hydrodynamic diameter. A The method of measuring this parameter is also described in ISO 13321:1996.

[0081] According to a first variant of the invention, the additive comprises one or more ligands specific to a molecule circulating in the blood. According to this variant, the ligand(s) are linked or grafted directly or indirectly by covalent bonding onto its vector, for example a nanoparticle or a polymer, typically a vector whose size is greater than the cut-off threshold of the dialysis membrane. The vector can advantageously make it possible, in particular, to increase the size of the ligand(s) in order to prevent their passage through the dialysis membrane. Several identical ligands can be covalently grafted onto the same vector (polymer or nanoparticles). Alternatively, different ligands, and in particular specifically binding different molecules, can be covalently grafted onto the same vector.

[0082] The indirect bonding or indirect grafting may be achieved by a molecular linker or spacer between the additive and the ligand, said linker or ligand being covalently bonded or grafted to the vector and the ligand.

[0083] According to a second variant of the invention, the additive consists of the specific ligand of a circulating molecule in the blood. This means that the additive is the ligand as such.

[0084] The choice of the first or second variant according to the invention depends in particular on the size of the specific ligand. Indeed, certain ligands specific to circulating blood molecules intrinsically have a size smaller than the cut-off threshold of the dialysis membrane and must therefore be linked directly or indirectly to a vector in order to remain in the dialysis fluid and not pass through the dialysis membrane.

[0085] Conversely, in the case where the ligand intrinsically has a size greater than the cutoff threshold of the membrane, it may not be bound to a nanoparticle or a polymer, and in this case it is considered to be the additive as such.

[0086] Thus, depending on the circulating molecules to be extracted from the blood with the dialysis system according to the invention, a person skilled in the art is able to determine with respect to the cut-off threshold of the dialysis membrane whether the additive used comprises a vector or consists essentially of said ligand specific to said circulating molecules.

[0087] According to a preferred embodiment, the additive is in solution or in suspension in an aqueous fluid, thus constituting a solution for dialysis fluid. According to this embodiment, the solution for dialysis fluid contains more than 0.01% by mass of additive, in particular more than 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, and preferably more than 0.5% by mass of additive. Advantageously, the solution for dialysis fluid comprises from 0.1% to 5% by mass of additive, preferably from 0.1 to 3%, more preferably from 0.1 to 1%, and very particularly from 0.1 to 0.5% by mass of additive.

[0088] According to a preferred embodiment, the dialysis system according to the invention comprises a dialysis reservoir with a capacity of from 0.5 to 10 liters, preferably from 1 to 7 liters and more preferably from 1 to 5 liters. Preferably, in this embodiment, the dialysis fluid is recirculated within said dialysis system.

[0089] Description of the ligands according to the invention:

[0090] The ligands suitable according to the invention are as described below, alone or in mixtures, and can advantageously be in solution.

[0091] According to a first embodiment variant, at least one ligand is specific to a circulating blood molecule involved in the mechanisms of the immune response and / or to a molecule activating the immune response.

[0092] According to a particular embodiment of this first variant, the ligand is specific for a pro-inflammatory cytokine or a chemokine. Non-limiting examples of pro-inflammatory cytokines include IFN-a, IFN-y, IL-1 [L IL-6, IL-12, IL-18, IL-33, TNF-a, and TGF[3. Non-limiting examples of chemokines include chemokine ligand 2 (CCL2), chemokine ligand 3 (CCL3), chemokine ligand 5 (CCL5), interleukin-8 (CXCL8), chemokine ligand 9 (CXCL9) and chemokine ligand 10 (CXCL10).

[0093] According to a particular embodiment, the ligand or ligand mixture is specific for IL-6, IFN-y, TNF- a, CCL2, CCL5, CXCL8, and / or CXCL10.

[0094] According to another particular embodiment of this first variant, the ligand specific for a circulating molecule in the blood is an antibody, in particular a recombinant monoclonal antibody, a mixture of antibodies, an antibody fragment binding the antigen, or a fusion protein comprising an antibody fragment. Typically, these are antibodies or fusion proteins directed specifically against a pro-inflammatory cytokine or a chemokine, for example as mentioned above and, preferably against interleukin-6, TNF-a, IFN-y, CCL2, I L-1 [L

[0095] According to another particular embodiment, the ligand is chosen from drugs directed against a pro-inflammatory cytokine or a chemokine, preferably from drugs directed against interleukin-6, TNF-a, IFN-y, CCL2, IL-1 [3, and mixtures thereof. In a more preferred embodiment, these drugs are drugs known to those skilled in the art, in particular for in vivo use, for example by subcutaneous or intravenous injection. Preferably, the ligand is chosen from drugs directed against interleukin-6, IFN-y and TNF-a.

[0096] Examples of drugs directed against interleukin-6 include Sirukumab, Siltuximab and Olokizumab.

[0097] Examples of drugs directed against TNF-alfa include Etanercept, Infliximab, Adalimumab, Golimumab, and Certolizumab.

[0098] An example of a drug directed against interferon gamma is notably Emapalumab marketed under the name Gamifant.

[0099] An example of a drug directed against CCL2 is notably NOX-36.

[0100] An example of a drug directed against interleukin-1B is notably Canakinumab.

[0101] According to a second embodiment variant which can, if appropriate, be combined with the first variant, a ligand is specific to the metal cations circulating in the blood, for example the metal cations involved in oxidative stress.

[0102] According to a particular embodiment of this variant, the metal cations are preferably trace metals chosen from the cations of the metals copper (Cu), iron (Fe), zinc (Zn), manganese (Mn), magnesium (Mg), cobalt (Co) and calcium (Ca), and most preferably Cu, Fe and Zn.

[0103] According to this embodiment, the ligand may be a molecule complexing metal cations.

[0104] Thus, the ligand can be chosen from the following complexing molecules: DOTA (1,4,7,10-tetraazacyclododecane-N,N',N”,N'”-tetraacetic acid), DTPA (diethylenetriaminepentaacetic acid), EDTA (2,2',2",2"'-(ethane-1,2-diyldinitrilo)tetraacetic acid), TTHA (3,6,9,12-tetrakis(carboxymethyl)-3,6,9,12-tetraazatetradecane-1,14-dioic acid), EGTA (ethylene glycol-bis(2-aminoethylether)-N,N,N',N'-tetraacetic acid), BAPTA (1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid), NOTA (acid 1,4,7-triazacyclononane -1,4,7-triacetic acid), DOTAGA ((2-(4,7,10-tris(carboxymethyl)-1,4,7,10-tetraazacyclododecan-1-yl)pentanedioic acid), DFO (deferoxamine), amide derivatives such as DOT AM (1,4,7,10-tetrakis(carbamoylmethyl)-1,4,7,10 tetraazacyclododecane) or NOTAM (1,4,7-tetrakis(carbamoylmethyl)-1,4,7-triazacyclononane), as well as mixed carboxylic acid / amide derivatives, phosphonic derivatives such as DOTP (1,4,7,10-tetraazacyclododecanel,4,7,10-tetrakis(methylene phosphonate)) or NOTP (1,4,7-tetrakis(methylene phosphonate)-1,4,7-triazacyclononane), cyclam derivatives such as TETA (1,4,8,11-tetraazacyclotetradecane-N,N',N",N"'- tetraacetic acid), TETAM (1,4,8,1 l-tetraazacyclotetradecane-N,N',N",N"'- tetrakis(carbamoylmethyl)), TETP (1,4,8,1 l-tetraazacyclotetradecane-N,N',N",N"'- tetrakis(methylene phosphonate)), siderophores or molecules derived from siderophores, their derivatives, and / or mixtures thereof. Preferably, the ligand is a cyclic ligand such as DOTA or a derivative of DOTA, such as for example DOTAGA.

[0105] For good specificity with iron, the ligand can advantageously be chosen from siderophore derivatives, in particular deferoxamine (DFO).

[0106] Advantageously, the complexation constant log(KCl) of the complexing molecule for at least one metal cation is greater than or equal to 10, preferably greater than or equal to 15.

[0107] According to a particular embodiment, the complexation reaction may be a transmetallation, i.e. an exchange of two metal cations. In such a case, the ligand may be pre-complexed with a first metal cation which will subsequently be exchanged with the circulating metal cation to be extracted from the blood. According to this embodiment, when the ligand is pre-complexed with a first metal cation the complexation constant log(KCl') for the first metal cation is lower than the complexation constant log(KCl) of the circulating metal cation to be extracted. Pre-complexation with Zn(II) or with an alkaline-earth cation, for example Ca(II) or Mg(II), is particularly advantageous, and makes it possible to directly provide a supplement of trace elements which could be critical in the context of the patient's progress.

[0108] Advantageously, the dialysis system makes it possible to extract metal cations from the blood of a mammal when the content of said metal cations is less than 1 ppm, preferably less than 0.1 ppm, more preferably less than 0.01 ppm.

[0109] Advantageously, the dialysis system makes it possible to extract cytokines from mammalian blood when the content of said cytokines is less than 1 ppb, preferably less than 0.1 ppb, and even more preferably less than 0.01 ppb.

[0110] According to a third embodiment, the additive comprises a mixture of one or more ligands specific for circulating blood molecules involved in the mechanisms of the immune response and / or activating the immune response as defined previously (for example one or more antibodies directed against T interleukin-6, TNF-a, IFN-y, CCL2, and / or IL-113) and a ligand specific for metal cations circulating in the blood as defined previously.

[0111] According to a particular embodiment of this variant, the additive comprises one or more ligands specific to pro-inflammatory cytokines or a chemokine, such as for example one or more drugs listed above, and one or more molecules complexing metal or trace metal cations, as defined previously.

[0112] Advantageously, the ligand may be present in the dialysis fluid in a proportion of between 1 picomolar and 1 nanomolar and / or between 1 pg / l and 1 mg / l.

[0113] Description of the additives according to the invention:

[0114] According to a first embodiment variant, the additive consists essentially of a specific ligand as defined previously and has a size greater than the cut-off threshold of the dialysis membrane.

[0115] According to a particular embodiment, the additive has a size greater than 50 kDa relative to the cut-off threshold of the membrane, and more preferably greater than 100 kDa relative to the cut-off threshold of the membrane.

[0116] According to a second embodiment variant, the additive comprises the nanoparticles as a vector.

[0117] According to this embodiment variant, the additive comprises at least one ligand covalently bound or grafted onto the nanoparticle, said ligand possibly being as defined previously.

[0118] The ligand can advantageously be grafted onto the nanoparticles in a mass proportion of between 1 and 90%, preferably between 10 and 80%, and more preferably between 20 and 60%.

[0119] The nanoparticles preferably used according to this embodiment may be based on silica or polysiloxane, preferably based on polysiloxane.

[0120] The term “silica or polysiloxane-based nanoparticles” means nanoparticles characterized by a mass percentage of silica or polysiloxane of at least 8%.

[0121] According to this embodiment, the nanoparticles may have an average diameter of between 5 and 50 nm.

[0122] According to this embodiment, the nanoparticles may have an average size greater than 20 kDa and less than 1200 kDa.

[0123] According to a third embodiment variant, the additive comprises a polymer as a vector onto which one or more ligands are covalently grafted (hereinafter polymer-based additive).

[0124] According to this embodiment variant, the polymer-based additive comprises at least one covalently bonded or grafted ligand, said ligand possibly being as defined previously.

[0125] The term “polymer” means any macromolecule formed from the covalent chaining of a very large number of repeating units which derive from one or more monomers.

[0126] According to a preferred embodiment, the polymer is biocompatible.

[0127] The polymers preferably used according to this embodiment variant are for example chosen from polysaccharides, polyacrylamides, polyamines, polyethylene glycols, polyvinyl alcohols, polycarboxylic acids, and mixtures thereof. Preferably, the polymer is a polysaccharide, and more preferably, chitosan.

[0128] Advantageously, the polymer-based additive has a hydrodynamic diameter of from 1 nm to 1 pm and / or from 100 kDa to 2000 kDa.

[0129] The number of ligands bound or grafted onto the polymer varies depending on the size of said ligand. For example, if the ligand has a size of less than 10 kDa, it can advantageously be grafted onto the polymer in a proportion in number of between 10 and 5000, preferably between 50 and 2500, and more preferably between 100 and 1000 per polymer.

[0130] For example also, if the ligand has a size of between 10 and 100 kDa, it can advantageously be grafted onto the polymer in a proportion in number of between 0.1 and 100, preferably between 1 and 50, and more preferably between 1 and 10 per polymer.

[0131] Advantageously, the polymer-based additive may be present in the dialysis fluid at a concentration of 0.1 to 10 g / l.

[0132] According to a fourth embodiment variant, the additive is a biomolecule, for example a protein, a peptide, or a polypeptide, a nucleic acid, or a polysaccharide.

[0133] For the purposes of the invention, the term "biomolecule" preferably refers to a natural biological molecule or its derivatives, and fragments comprising a region specifically binding a circulating blood molecule. In particular, a biomolecule is an immunoglobulin, a fusion protein, a structural protein, for example a recombinant protein and their modified versions. It may be, for example, a peptide, polypeptide or recombinant protein. Biomolecules may be modified, in particular to increase their molecular mass. Technologies for increasing the molecular mass of a peptide, polypeptide or recombinant protein are well known to those skilled in the art and include, in particular, pegylation, hesylation or other similar technologies.

[0134] According to a preferred embodiment, the biomolecule is essentially constituted of a ligand specific to a circulating molecule in the blood as defined previously.

[0135] According to a fifth embodiment variant, the dialysis fluid comprises a mixture of additives as defined in the preceding variants.

[0136] Preferred embodiments of the additive.

[0137] According to a preferred embodiment, the additive comprises a chitosan polymer onto which is grafted as a ligand a molecule complexing metal cations. Preferably, the complexing molecule is then DOTAGA and / or DFO and / or one of their derivatives.

[0138] According to another preferred embodiment, the dialysis fluid of the system according to the invention comprises polysiloxane nanoparticles onto which a molecule complexing metal cations is grafted as a ligand. Preferably, the complexing molecule is DOT AG A.

[0139] According to another particular embodiment, the dialysis fluid of the system according to the invention comprises several additives chosen from: - polysaccharides having a mass of 100 kDa to 1200 kDa, for example at a concentration of 0.1 to 10 g / l in the dialysis fluid, where appropriate, onto which molecules complexing metal cations are covalently grafted, for example in a number proportion of between 50 and 5000, and preferably between 100 and 1000 per polysaccharide, - specific ligands of circulating blood molecules as defined above, said ligand having a size greater than 100 kDa, preferably in a proportion of between 1 μg / l and 1 g / l in the dialysis fluid, and / or - polysaccharides onto which specific ligands of circulating blood molecules as defined above are covalently grafted, said ligands having a size of between 10 and 100 kDa, for example in a number proportion of between 0.1 and 100 and preferably between 1 and 10 per polysaccharide.

[0140] Another subject of the invention also relates to an additive solution for dialysis fluid or a dialysis fluid comprising one or more additives as defined previously comprising or consisting of a ligand specific to a circulating molecule as defined previously.

[0141] In particular, the dialysis fluid additive solution may consist of a stock solution comprising an effective amount of additive for use in the dialysis device, after dilution in the dialysis fluid.

[0142] The dialysis fluid comprises an effective amount of said additive, where appropriate with other conventional constituents of a dialysis fluid.

[0143] By a judicious choice of additive and / or ligand, the dialysis system according to the invention makes it possible to extract circulating molecules from the blood of a mammal, and in a specific manner, in particular for therapeutic purposes. Also, the invention also relates to said additive solution or dialysis fluid for all the uses of the dialysis system, described in the present description.

[0144] Many diseases are in fact linked to the production or overproduction of molecules circulating in the blood, for example pro-inflammatory cytokines or chemokines, the accumulation of which causes an imbalance which can be harmful to the mammal if it persists for too long.

[0145] Thus, the dialysis system according to the invention, by the specific extraction of circulating molecules from the blood produced or over-produced during a disease, makes it possible to treat and / or prevent said diseases.

[0146] One of the advantages of the present invention is to avoid administering active compounds directly to the patient. It advantageously makes it possible to reposition compounds, drugs, known to those skilled in the art for their capacity to capture molecules circulating in the blood, for example, inflammatory cytokines, with a view to their use in a dialysis system for the ex vivo (and no longer in vivo) capture of said undesirable circulating molecules, and this, for therapeutic purposes, for example to treat ARDS.

[0147] Consequently, another object of the invention relates to the use of the dialysis system as described above, for the treatment of a human patient in acute failure and / or in intensive care, by ex vivo capture of molecules circulating in the blood.

[0148] As previously described, ARDS is a syndrome associated with COVID-19. In addition, cytokine storm is considered one of the main causes of ARDS and multiple organ failure and plays an important role in the disease worsening process. Finally, just like MERS and SARS, people suffering from COVID-19 have elevated levels of pro-inflammatory molecules.

[0149] Thus, another object of the invention relates to the use of the dialysis system as described above in the prevention and / or treatment of diseases chosen from sepsis, acute respiratory distress syndrome (ARDS), cytokine shock, septic shock, systemic inflammatory responses, and macrophage activation syndrome also called hemophagocytic lymphohistocytosis (HLH).

[0150] According to this object, the dialysis fluid of the dialysis system comprises at least one additive chosen from nanoparticles, polymers and biomolecules as defined previously, said additive having a size greater than the cut-off threshold of said porous dialysis membrane, and comprises or consists of a ligand specific for a circulating molecule in the blood involved in the mechanisms of the immune response and / or a molecule activating the immune response, preferably the ligand is specific for a pro-inflammatory cytokine or a chemokine.

[0151] The additive and / or the ligand are as defined previously.

[0152] Indeed, these diseases are associated with a significant release of pro-inflammatory molecules, in particular cytokines, and / or chemokine which is harmful to the organism. The extraction of these molecules by the dialysis system according to the invention therefore makes it possible to prevent or treat the mammal.

[0153] According to a particular embodiment, the dialysis system according to the invention can be used in the prevention and / or treatment of diseases chosen from sepsis, acute respiratory distress syndrome (ARDS), cytokine shock and systemic inflammatory responses caused by a viral infection, preferably a coronavirus infection, in particular a COVID-19 infection.

[0154] As mentioned earlier, oxidative stress is a harmful situation for the body that causes biological damage. It occurs when the amount of pro-oxidant molecules is greater than that of antioxidants. Pro-oxidant molecules are mainly composed of reactive oxygen species and reactive nitrogen species. In sepsis conditions, an overproduction of ROS and RNS is observed both in the bloodstream and in damaged organs.

[0155] Thus, another object of the invention relates to the use of the dialysis system as described previously in the prevention and / or treatment of oxidative stress.

[0156] According to this object, the dialysis fluid of the dialysis device comprises at least one additive chosen from additives based on nanoparticles, polymers or biomolecules as defined previously, said additive having a size greater than the cut-off threshold of said porous dialysis membrane, and comprises or is made up of an additive comprising or made up of a ligand specific for the circulating molecules involved in oxidative stress.

[0157] The additive and / or the ligand are as defined previously.

[0158] According to a particular embodiment, the dialysis fluid of the dialysis device comprises an additive comprising or consisting of a ligand specific to metal cations, more preferably trace metals chosen from the cations of the metals copper (Cu), iron (Fe), zinc (Zn), manganese (Mn), cobalt (Co), magnesium (Mg), and calcium (Ca), and most preferably Cu, Fe and Zn.

[0159] According to this embodiment, the ligand may be a molecule complexing metal cations.

[0160] Another object of the invention relates to the use of the dialysis system as described above for reducing the growth or proliferation of a pathogen, for example reducing the bacterial load, in a mammal.

[0161] According to this object, the dialysis fluid of the dialysis system comprises at least one additive chosen from additives based on nanoparticles, polymers and biomolecules as defined previously, said additive having a size greater than the cut-off threshold of said porous dialysis membrane, and comprises or consists of at least one ligand chosen from molecules complexing the metal cations Cu, Fe, Zn, Mn, Mg, and Ca.

[0162] Another subject of the invention relates to a method for treating a disease chosen from sepsis, acute respiratory distress syndrome (ARDS), cytokine shock, septic shock, macrophage activation syndrome (MAS) or hemophagocytic lymphohistocytosis (HLH), and systemic inflammatory responses in a patient in need thereof, said method comprising the implementation of a dialysis system as defined above in which the dialysis fluid comprises at least one additive chosen from nanoparticles, polymers and biomolecules, said additive having a size greater than the cut-off threshold of said porous dialysis membrane, and comprises or consists of at least one ligand specific for a circulating blood molecule involved in the mechanisms of the immune response and / or an activating molecule of the immune response, preferably the ligand is specific for a pro-inflammatory cytokine or a chemokine.

[0163] In one embodiment, the treatment method comprises in particular, a step of placing the dialysis system in a subject in need using a catheter on a vein of said subject, a step of dialysis by extracorporeal circulation of the blood of said subject, with a volume of dialysis fluid of between 0.1 and 10 liters and for a time sufficient to allow the extraction of the circulating molecules involved in the mechanisms of the immune response and / or of a molecule activating the immune response.

[0164] According to a particular embodiment, the dialysis fluid is circulated at a speed of 10 to 300 ml / min, in single current or counter-current.

[0165] According to a particular embodiment, the circulation flow rate is from 40 to 100 ml / min.

[0166] According to a preferred embodiment, the dialysis fluid is recirculated in the dialysis system. This recirculation makes it possible to optimize the extraction of circulating molecules from the blood for a given quantity of additive present in the dialysis fluid. In this way, the final volume of dialysis fluid consumed is reduced, as are the quantities of additive to be used.

[0167] According to a particular embodiment, the dialysis system is implemented for a duration of 2 to 200 hours, preferably 4 to 48 hours.

[0168] This treatment method is particularly suitable for treating subjects suffering from viral infection, in particular a viral infection caused by a coronavirus such as COVID-19, but also for subjects in acute failure and / or in intensive care.

[0169] The additive and / or the ligand are as defined previously.

[0170] Preferably, the ligand is specific for a pro-inflammatory molecule, and more preferably, for a pro-inflammatory cytokine, such as for example interleukin-6, interferon-y or TNF-a.

[0171] Another subject of the invention relates to a method for reducing oxidative stress in a patient in need thereof, said method comprising the implementation of a dialysis system as defined above in which the dialysis fluid comprises at least one additive chosen from nanoparticles, polymers and biomolecules, said additive having a size greater than the cut-off threshold of said porous dialysis membrane, and comprises or consists of at least one ligand specific for the metal cations circulating in the blood.

[0172] The additive and / or the ligand are as defined previously.

[0173] Preferably, the ligand is chosen from molecules complexing trace metals. chosen from the cations of the metals copper (Cu), iron (Fe), zinc (Zn), cobalt (Co), manganese (Mn), magnesium (Mg), and calcium (Ca), and most preferably Cu, Fe and Zn.

[0174] In one embodiment, the treatment method comprises in particular, a step of placing the dialysis system in a subject needing it using a catheter on a vein of said subject, a step of dialysis by extracorporeal circulation of the blood of said subject, with a volume of dialysis fluid of between 1 and 7 liters and for a time sufficient to allow the extraction of the metal cations circulating in the blood.

[0175] According to a particular embodiment, the dialysis fluid is circulated at a speed of 10 to 300 ml / min, in single current or counter-current.

[0176] According to a particular embodiment, the circulation flow rate is between 40 and 100 ml / min.

[0177] According to a preferred embodiment, the dialysis fluid is recirculated in the dialysis system.

[0178] According to a particular embodiment, the dialysis system is implemented for a duration of 2 to 20 hours, preferably 2 to 15 hours.

[0179] This treatment method is advantageously suitable for treating subjects suffering from viral infection, in particular a viral infection caused by a coronavirus such as COVID-19, but also for subjects in acute failure and / or in intensive care.

[0180] Another subject of the invention also relates to a method for reducing, limiting or stopping the growth of a pathogen in a patient in need thereof, said method comprising the implementation of a dialysis system as defined above in which the dialysis fluid comprises at least one additive chosen from nanoparticles, polymers and biomolecules, said additive having a size greater than the cut-off threshold of said porous dialysis membrane, and comprises or consists of at least one ligand chosen from molecules complexing the metal cations Cu, Fe, Zn, Mn, Mg, and Ca and more particularly molecules complexing the cations Fe(III).

[0181] In one embodiment, the treatment method comprises in particular, a step of placing the dialysis system in a subject in need thereof using a catheter on a vein of said subject, a step of dialysis by extracorporeal circulation of the blood of said subject, with a volume of dialysis fluid of between 0.5 and 10 liters and for a time sufficient to allow the extraction of the metal cations of Cu, Fe, Zn, Mn, Mg, and Ca circulating in the blood.

[0182] According to a particular embodiment, the dialysis fluid is circulated at a speed of 10 to 300 ml / min, in single current or counter-current.

[0183] According to a particular embodiment, the circulation flow rate is between 40 and 100 ml / min.

[0184] According to a preferred embodiment, the dialysis fluid is recirculated in the dialysis system.

[0185] According to a particular embodiment, the dialysis system is implemented for a duration of 4 to 100 hours, preferably 4 to 48 hours. Examples

[0186] Example 1

[0187] An extracorporeal circulation is installed on a patient, a peristaltic pump allows blood circulation at a flow rate of 200 ml / min. The blood then passes through a Theralite type dialysis system, having 2.1 m2 of membranes based on polyarylethersulfone and polyvinylpyrrolidone and a high cut-off threshold (HCO) allowing the passage of molecules with a molecular weight up to 45 kDa.

[0188] A reservoir containing 3 liters of dialysis fluid is then connected to the dialysis cartridge and recirculated within the cartridge by a peristaltic pump. The circulation speed of the dialysis fluid is set at 100 ml / min. The dialysis fluid is obtained by mixing 3 liters of conventional dialysis solution (for example PrismaSol or Prismocal) and 100 ml of a 10 g / l chitosan solution onto which DOTAGA complexing molecules are grafted (containing around 1 millimole of DOTAGA complexing agent).

[0189] To this solution are added 100 ml of a saline solution containing 1 g / l of Golimumab or equivalent (anti-TNF-a antibody) and 1 g / l of Olokizumab or equivalent (anti-IL-6 antibody) and 0.1 g / l of Emapalumab (anti-IFN-y antibody).

[0190] The dialysis system is put into circulation for 12 hours. During these 12 hours, the treatment allows cations to be specifically extracted from the blood metals, especially iron and copper and pro-inflammatory cytokines: IL-6 and TNF-a.

[0191] Example!

[0192] A patient is connected to a dialysis system under operational condition allowing continuous veno-venous hemodialysis (CVVHD). The dialysis monitor is a prismaflex system.

[0193] An HF20 kit (Prismaflex HF 20 set) is used, it contains 0.2 m2 of PAES (Polyarylethersulfone) dialysis membranes.

[0194] In a 5L bag of PrismaSol (or Prismocal), 100 ml of a MEX-CD1 solution containing 10 g / l of chitosan-DOTAGA and 10 ml of a 1 g / l solution of Sirikumab (anti-IL6 antibody) are introduced successively. This mixture is then used as a dialysis fluid solution.

[0195] The dialysis fluid is then circulated at a speed of 1.25 L / hour in counter-current. The blood circulation rate is set at 60 ml / min.

[0196] After 4 hours of treatment, the dialysis system can specifically reduce the amount of iron and copper circulating in the blood, as well as the amount of cytokine IL-6. Such a system can thus treat a patient with septic shock.

[0197] To increase efficiency, the operation is repeated at least 4 times, using the same liquid after recirculation. After five uses, the dialysis cartridge is changed, as is the dialysis fluid by reconstituting it as initially used.

[0198] 10 ml of a 1g / l solution of Adalimumab-type antibodies are added in order to to specifically extract a portion of the TNF-a molecules circulating in the blood and thus limit immune runaway. List of cited documents

[0199] For all useful purposes, the following non-patent elements are cited: - nplcitl : P. Mehta, D. F. McAuley, M. Brown, E. Sanchez, R. S. Tattersall, J. J. Manson, COVID-19 : consider cytokine storm syndromes and immunosuppression, The Lancet, 2020, 395, 1033-1034. - nplcit2 : Q. Ye, B. Wang, J. Mao, Cytokine Storm in COVID-19 and Treatment, Journal of Infection, 2020, 10.1016 / j.jinf.2020.03.037. - nplcit3 : M. A. Wutjewicz, A. Dylczyk-Sommer, A. Aszkielowicz, S. Zdanowski, S. Piwowarczyk, R. Owczuk, COVID-19 - what should anaethesiologists and intenisvists know about it, Anaesthesiol. Intensive Ther., 2020, 52, 34-41. - nplcit4 : X. Li, M. geng, Y. Peng, L. Meng, S. Lu, Molecular immune pathogenesis and diagnosis of COVID-19, Journal of Pharmaceutical Analysis, 2020. - nplcit5 : C. Huang, Y. Wang, X. Li, L. Ren, J. Zhao, Y. Hu, L. Zhang, G. Fan, J. Xu, X. Gu, Z. Cheng, T. Yu, J. Xia, Y. Wei, W. Wu, X. Xie, W. Yin, H. Li, M. Liu, Y. Xiao, H. Gao, L. Guo, J. Xie, G. Wang, R. Jiang, Z. Gao, Q. Jin, J. Wang, B. Cao, Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China, 2020, 395, 497-506.

[0200] - nplcitô : L. Li, R. Li, Z. Wu, X. yang, M. Zhao, J. Liu, D. Chen, Therapeutic strategies for critically ill patients with COVID-19, Ann. Intensive Care, 2020,10, 45. - nplcit7 : C. Zhang, Z. Wu, J.-W. Li, H. Zao, G-Q. Wang, The cytokine release syndrome (CRS) of severe COVID-19 and Interleukin-6 receptor (IL-6R) antagonist Tocilizumab may be the key to reduce the mortality, International Journal of Antimicrobial Agents, 2020. - nplcit8 : H. Li, L. Liu, D. Zhang, J. Xu, H. Dai, N. Tang, X. Su, B. Cao, SARS-CoV-2 and viral sepsis : observations and hypothèses, 2020. - nplcit9 : Q. Ruan, K. Yang, W. Wang, L. Jiang, J. Song, Clinical predicators of mortality due to COVID-19 based on an analysis of data of 150 patients from Wuhan, China, Intensive Care Med., 2020. - nplcitlO : B. M. Henry, M. H. Santos de Oliveira, S. benoit, M. Plebani, G. Lippi, Hématologie, biochemical and immune biomarker abnormalities associated with severe illness and mortality in coronavirus disease 2019 (COVID-19): a meta-analysis, Clin. Che. Lab. Med., 2020. - nplcitl 1 : J. Ma, P. Xia, Y. Zhou, Z. Liu, X. Zhou, J. Wang, T. Li, X. Yan, L. Chen, S. Zhang, Y. Qin, X. Li, Potential effect of blood purification therapy in reducing cytokine storm as a late complication of critically ill CoVID-19 patients, Clin. Immunol., 2020, 214, 108408. - nplcitl2 : Y. Xia, N. Farah, A. Maxan, J. Zhou, C. Lehmann, Therapeutic iron restriction in sepsis, Medical Hypothèses, 2016, 89, 37-39. - nplcitl3 : B. G. Chousterman, F. K. Swirski, G. F. Weber, Cytokine storm and sepsis disease pathogenesis, Semmin. Immunopathol., 2017, 39, 517-528. - nplcitl4 : P. M. Honore, E. Hoste, Z. Molnar, R. Jacobs, O. Joannes-Boyau, M. L. N. G. Malbrain, L. G. Fomi, Cytokine removal in human septic shock: where are we and where are we going, Ann. Intensive Care, 2019, 9, 56. - nplcitl5 : T. Rimmelé, J. A. Kellum, Clinical review: blood purification for sepsis, Critical Care, 2011, 75, 205.

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[0202] - nplcit 17 : S. Islam, S. Jarosch, J. Zhou, M. del Carmen Parquet, J. T. Toguri, P. Colp, B. E. Holbein, C. Lehmann, Anti-inflammatory and anti-bacterial effects of iron chélation in experimental sepsis, 2016, 200, 266-273.

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Claims

Claims

1. A dialysis system capable of being connected to an extracorporeal blood circulation device comprising: (a) a porous dialysis membrane, and (b) a reservoir comprising a dialysis fluid, characterized in that the dialysis fluid comprises at least one additive selected from nanoparticles, polymers and biomolecules having a size greater than the cut-off threshold of said porous dialysis membrane, and which comprises or consists of at least one ligand specific for a molecule circulating in the blood of a mammal selected from the group comprising an antibody, a recombinant monoclonal antibody, a mixture of antibodies, an antibody fragment binding the antigen, or a fusion protein comprising an antibody fragment, characterized in that said ligand is specific for a pro-inflammatory cytokine selected from IFN-a, IFN-y, IL-1[3, IL-6, IL-12, IL-18, IL-33, TNF-a, and TGF[3,or a chemokine selected from chemokine ligand 2 (CCL2), chemokine ligand 3 (CCL3), chemokine ligand 5 (CCL5), interleukin-8 (IL-8), chemokine ligand 9 (CCL-9) and chemokine ligand 10 (CCL10).,

2. Dialysis system according to claim 1, characterized in that the ligand is specific for IL-6, IFN-y, TNF-a, CCL2, CCL5, CXCL8, and / or CXCL10.

3. Dialysis system according to one of claims 1 and 2, characterized in that the specific ligand is present in the dialysis fluid in a proportion of between 1 picomolar and 1 nanomolar and / or between 1 pg / l and 1 mg / L

4. Dialysis system according to any one of claims 1 to 3, characterized in that at least one of said ligands is chosen from drugs directed against interleukin-6 (Sirukumab, Olokizumab), interferon y (Emapalumab), TNF-alfa (Etanercept, Infliximab, Adalimumab, Golimumab, Certolizumab), CCL2 (NOX-E36), interleukin-1B (Canakinumab), and mixtures thereof.

5. Dialysis system according to any one of claims 1 to 4, characterized in that said porous dialysis membrane has a surface area of at least 0.1 m2.

6. Dialysis system according to any one of claims 1 to 5, characterized in that the additive is chosen from nanoparticles having an average diameter of 3 to 50 nm, said specific ligand being covalently grafted onto said nanoparticle.

7. Dialysis system according to any one of claims 1 to 6, characterized in that the additive is chosen from polymers, said specific ligand being covalently grafted onto said polymer, for example biocompatible polymers such as polysaccharides, or a biomolecule, and said additive has a size greater than 100 kDa, and preferably less than 1200 kDa.

8. Dialysis system according to any one of claims 1 to 7, characterized in that it also comprises at least one ligand specific for circulating molecules involved in oxidative stress, in particular is a ligand specific for metal cations circulating in the blood.

9. Dialysis system according to claim 8, characterized in that said ligand specific for circulating molecules involved in oxidative stress is a molecule complexing metal cations chosen from the following complexing molecules: DOTA, DTPA, EDTA, TTHA, EGTA, BAPTA, NOTA, DOTAGA, DFO, DOTAM, NOTAM, DOTP, NOTP, TETA, TET AM, TETP and DTPABA, their derivatives and / or their mixtures.