Protected amino acid preparations for use in peritoneal dialysis - Patent Application 20070122997

Abstract

The present invention relates to a protective agent selected from the group consisting of L-glutamine, L-alanyl-L-glutamine, L-glutaminyl-L-alanine, L-glutaminyl-L-glycine, L-glycinyl-L-glutamine, or a mixture thereof, for particular use in the prevention and / or treatment of (A) liver disease induced by said peritoneal dialysis treatment, and / or (B) diseases associated with end-stage renal disease (ESKD) mediated by liver dysfunction induced by said peritoneal dialysis treatment during the course of peritoneal dialysis treatment, wherein the protective agent is administered by intraperitoneal administration.

Description

[Technical Field]

[0001] The present invention relates to a protective agent for use in peritoneal dialysis treatment, as well as certain therapeutic uses and methods of treatment using said protective agent. [Background technology]

[0002] Chronic kidney disease (CKD) and loss of renal function result in retention of uremic toxins and fluid overload, which is most pronounced in patients with end-stage kidney disease (ESKD) (1). ESKD is also strongly associated with increased risk for systemic inflammation, including metabolic inflammation, defined as a chronic low-grade inflammatory state induced by metabolic alterations. Furthermore, ESKD is associated with atherosclerosis and cardiovascular disease (CVD) (2).

[0003] Peritoneal dialysis (PD) is a home-based renal replacement therapy for ESKD with comparable survival rates compared to hemodialysis (HD) (3). Using sterile procedures, peritoneal dialysate (PDF) is infused into the peritoneal cavity and removed after a dwell time of several hours. PD reduces uremic toxins and fluid overload through the diffusion of small solutes and ultrafiltration of water across the peritoneal membrane, driven primarily by a hyperosmolar glucose- or colloid-based PDF pressure gradient. While providing life-saving renal replacement, PD also carries typical procedure-related complications in addition to the uremia-related morbidity of ESKD (3). Chronic exposure to PDF results in a high intraperitoneal load of glucose and its degradation products (GDPs), which are associated with inflammatory and vascular changes (4, 5), potentially promoting metabolic and cardiovascular risk profiles (6).

[0004] Most commercially available PDFs contain glucose monohydrate as their primary osmotic agent. Alternatively, PDFs may contain glucose polymers (i.e., icodextrin) or colloidal osmotic agents (e.g., amino acids, peptides).

[0005] Several clinical and experimental observations have shown that PDFs are cytotoxic and carry a risk of technical failure of up to 30% in long-term PD procedures ( 7 ).

[0006] WO2008 / 106702A1 provides a glucose-based peritoneal fluid containing a protective agent in the form of a dipeptide capable of releasing L-glutamine, which is L-glutamine-releasing dipeptide L-glutamine-glutaminyl-L-glycine, L-glycinyl-L-glutamine, L-glutaminyl-L-alanine, or L-alanyl-L-glutamine, or a mixture of two or more of the dipeptides, wherein the concentration of the dipeptide in the dialysis solution is 2 mM to 25 mM.

[0007] According to this patent application, it has been found that these dipeptides, in particular L-alanyl-L-glutamine (hereinafter also abbreviated as alanyl-glutamine or as "Ala / Gln"), contribute to the prevention of technical failures.

[0008] The common thread among these protective agents is their ability to release L-glutamine, and therefore, although reference will be made primarily to alanyl-glutamine below, it is expected that the reported effects will also be achieved with other protective agents from the aforementioned group.

[0009] Several publications have further explored the effect of Ala / Gln on glucose-based PDFs ( 8 – 26 ).

[0010] The liver is increasingly recognized as a central hub linking metabolism and CVD (27). To ensure the liver can withstand exposure to gut-derived microbial and dietary molecules, metabolic activity and associated inflammatory processes are tightly regulated. Stimulation occurs when liver-tropic pathogens or toxic products of metabolic activity require elimination (28). Several studies have demonstrated an epidemiological correlation between CKD and chronic liver disease, with recent emphasis on metabolic stress contributing to renal-liver crosstalk (29, 30).

[0011] In CKD, the liver can be both a victim organ, developing specific pathologies such as metabolic dysfunction-associated fatty liver disease (MAFLD), and a victim organ, mediating the environment that drives CKD-associated CVD. The liver's central role in detecting and responding to extrahepatic and intrahepatic signals is achieved through an acute-phase response that amplifies inflammatory stimuli by several orders of magnitude. Hepatocytes produce acute-phase proteins (e.g., complement proteins, C-reactive protein [CRP]), which then promote systemic inflammation through direct effector functions (27, 28).

[0012] Although these pathological mechanisms are quite common in ESKD patients treated with PD, the inventors of the present invention are not aware of any mechanistic studies linking PD to liver disease or elucidating the role of PD-induced liver dysfunction in PD-associated conditions such as CVD.

[0013] Clinical studies linking PD and the liver are limited and inconclusive. Previous reports have demonstrated subcapsular hepatic fat deposition in PD patients and linked its occurrence to the combined use of intraperitoneal insulin and glucose-based PDFs, which was associated with higher peritoneal permeability and higher body weight (31, 32). Small cross-sectional studies have reported a high prevalence of chronic liver disease in PD patients, which has been associated with a higher risk of atherosclerosis and therefore CVD (33). Some studies have reported that liver enzymes are higher in PD patients compared with HD patients (34), but other studies have not found this to be the case (35). Liberato et al. argued that the observed increase in gamma-glutamyltransferase (GGT) levels above the normative upper limit in both dialysis groups may be closely related to the dysnutrition-inflammation-atherosclerosis syndrome and thereby CVD (34). Therefore, in clinical PD, it was unclear whether there is a specific effect of PD on the liver and a role for the inflammatory response in PD-induced liver dysfunction.

[0014] Further background prior art is known from Ferrantelli Evelina et al., Kidney International 89(3)2016, 625-635 and Mikolasevic et al., Medical Hypotheses 82(2)2013, 205-208. Summary of the Invention [Problem to be solved by the invention]

[0015] It is an object of the present invention to provide an amelioration of the side effects associated with PD. [Means for solving the problem]

[0016] This problem is solved by the subject matter of claim 1.

[0017] Further preferred embodiments of the invention are disclosed in the dependent claims. [Brief explanation of the drawings]

[0018] [Figure 1] Hepatic inflammatory response induced by peritoneal dialysis. Control and uremic mice with and without PD. Inflammation score and nonalcoholic fatty liver disease (NAFLD) activity score (NAS). p-value calculated by Mann-Whitney U test without multiplicity correction. a, Changes in healthy animals. b, Changes in uremic animal model. [Figure 2] Effect of alanyl-glutamine supplementation of PDFs on the hepatic inflammatory response induced by PD. Control mice, uremic mice with PD, and uremic mice with PD and AlaGln supplementation. p values ​​calculated by the Mann-Whitney U test without multiplicity correction. a, Inflammation score and NAFLD activity score (NAS). b, Percentage area of ​​Oil Red O-stained tissue (= steatosis) in liver sections. c, Percentage area of ​​Sirius Red-stained tissue (= fibrosis) in liver sections. [Figure 3]Effect of alanyl-glutamine administration on specific biomarkers related to cardiovascular disease in control mice, uremic mice with PD, and uremic mice with PD and AlaGln supplementation. Abundance of APOH, CFB, and CRP in liver tissue assessed by mass spectrometry proteomic analysis. [Figure 4] Correlation of changes in different liver parameters and their association with changes in parameters of systemic inflammation due to alanyl-glutamine treatment in chronic PD patients. Secondary analysis of a prospective, multicenter, phase II study on the effect of alanyl-glutamine supplementation to PDF in chronic PD patients on clinical parameters of liver injury. a, Spearman rank correlation. Black tiles indicate positive correlations with p-values ​​< 0.1 (no multiplicity correction). White tiles indicate non-significant (p-values ​​≥ 0.1) positive correlations. b, Spearman rank correlation between changes in plasma interleukin-6 and changes in GGT levels (rho = 0.35, p = 0.03, no multiplicity correction). DETAILED DESCRIPTION OF THE INVENTION

[0019] The present inventors have analyzed for the first time the effect of PD itself on the liver in both uremic and non-uremic animals and have surprisingly found that PD itself, particularly using glucose-based PDFs, induces liver disease and therefore also increases the probability of diseases mediated by liver dysfunction.

[0020] In our study, uremic and non-uremic animals undergoing PD enabled mechanistic studies to elucidate the specific effects of PD on hepatic molecular responses in a tightly controlled experimental model of CKD. Experimental data indicate that PD treatment is associated with increased hepatic inflammation and acute-phase response, a novel treatment-specific adverse effect that may reduce its beneficial effects of reducing uremic intoxication and hyperhydration in ESKD patients. Furthermore, the experimental setting of PD in non-uremic animals in our study allows unique insights into the pathomechanisms associated with specific PD procedures that cannot be obtained by other methods. Interestingly, the results of these experiments clearly support differential expression of hepatic proteins related to hepatic acute-phase response signaling, without CKD as a confounding factor.

[0021] These data indeed suggest a direct causal role for specific PD factors in inducing hepatic inflammation and acute phase response signaling, and subsequent systemic inflammation, particularly metabolic inflammation, and CVD in PD patients. PDF-induced excess energy and nutrients transported directly to the liver (via portal vein outflow from the peritoneum) may result in metabolic stress, triggering metabolic inflammation and altered immune responses, thereby promoting both disease, i.e., liver disease and CVD.

[0022] In conclusion, we found direct evidence of PD-induced liver pathology and dysfunction. By applying an established chronic PD exposure model in both uremic and non-uremic mice, our histological and proteomic findings directly link chronic intraperitoneal PDF exposure to hepatic inflammation and liver-mediated systemic inflammation, particularly metabolic inflammation, via the peritoneal-hepatic portal axis, regardless of CKD.

[0023] The inventors have found that the protective agent used according to claim 1, in particular alanyl-glutamine, ameliorates the adverse effects of PDF on the liver when administered intraperitoneally during peritoneal dialysis treatment.

[0024] We investigated the potential effects of alanyl-glutamine supplementation on the liver in a chronic mouse PD model. This treatment resulted in significant reductions in PD-induced liver pathology and liver-mediated metabolic inflammation. Histological evidence that alanyl-glutamine mediates the reduction of PD-induced morphological liver pathology was demonstrated by an improvement in the NAFLD activity score (NAS), primarily driven by a reduction in inflammatory infiltrate. This morphological improvement was associated with corresponding molecular responses, which were demonstrated in the mouse liver proteome.

[0025] Alanyl-glutamine has been shown to attenuate hepatic reperfusion injury in rat models, protect mice from acute liver injury induced by LPS, and significantly reduce steatohepatitis and fibrosis in mouse NAFLD models (36-38).

[0026] However, the use of alanyl-glutamine to directly influence PD-induced liver disease and / or further liver-related negative consequences of PD has not been suggested so far.

[0027] Thus, in a first aspect, the present invention provides a method for administering a peritoneal dialysis treatment to a subject in the course of peritoneal dialysis, comprising: (A) liver disease induced by said peritoneal dialysis treatment, and / or (B) End-stage renal disease (ESKD)-associated disorders mediated by liver dysfunction induced by the peritoneal dialysis treatment. 1. A protective agent selected from the group consisting of L-glutamine, L-alanyl-L-glutamine, L-glutaminyl-L-alanine, L-glutaminyl-L-glycine, L-glycinyl-L-glutamine, or mixtures thereof, for particular use in the prevention and / or treatment of administered by intraperitoneal injection, Provide a protectant.

[0028] A further aspect of the present invention relates to the use of said protective agent in the prevention and / or treatment of said diseases (A) and / or (B) in the course of peritoneal dialysis treatment.

[0029] A further aspect of the invention relates to the use of said protectant in the manufacture of a medicament for the treatment or prevention of said diseases (A) and / or (B) in the course of peritoneal dialysis treatment.

[0030] A further aspect of the present invention relates to a method for the prevention and / or treatment of said diseases (A) and / or (B) by administering said protective agent via intraperitoneal administration to a subject in need thereof during the course of peritoneal dialysis treatment.

[0031] The following discussion relates to any of the above embodiments mutatis mutandis.

[0032] In a preferred embodiment of the present invention, the liver disease (A) induced by peritoneal dialysis treatment is a chronic liver disease, in particular non-infectious hepatitis.

[0033] Non-infectious hepatitis includes diseases such as non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), and metabolic (dysfunction)-associated fatty liver disease (MAFLD).

[0034] In patients with ESKD, the pathophysiological mechanisms linking PD and the liver cannot be separated from the influence of renal-liver crosstalk in CKD and its chronic low-grade inflammatory and metabolic factors (e.g., associated with atherogenic dyslipidemia and hyperglycemia) (30). CKD shares many risk factors with fatty liver disease (e.g., obesity, hypertension, insulin resistance, type 2 diabetes, and atherogenic dyslipidemia), and therefore, the prevalence of CKD in nonalcoholic fatty liver disease (NAFLD) populations is significantly greater, approximately 20–55%, compared with 5–35% in non-NAFLD populations (39). Furthermore, several studies have demonstrated a correlation between CKD and NAFLD and described a broader phenotype of metabolically impaired fatty liver disease (MAFLD), with a stronger emphasis on the pathogenetic role of metabolic dysfunction and the increased risk for CVD due to CKD, MAFLD, and their shared and non-shared risk factors (29, 30, 40-43). In a population-based study, the positive association between the fatty liver index, a marker of hepatic steatosis, and CKD incidence was entirely mediated by the joint action of the most important cardiometabolic risk factors (44). Markers of liver pathology were significantly correlated with serum CRP, ALT, AST, and lipid markers (i.e., cholesterol, LDL, triglycerides), as well as CVD in dialysis patients (45). Furthermore, liver function parameters were positively correlated with poor outcomes, CVD, and all-cause mortality in patients with ESKD and PD (46).

[0035] So far, no data on the effects of alanyl-glutamine on liver injury and liver-mediated systemic metabolic inflammation (potentially driving CVD) have been reported in PD patients.

[0036] Therefore, in addition to the experiments in animal models described above, we set out to perform a secondary outcome analysis of a recent clinical PD trial (in human patients, 8) to validate those experimental findings.

[0037] As a result of this novel analysis, we were able to identify a significant reduction in clinical parameters of liver injury upon addition of alanyl-glutamine to PDFs, which reached statistical significance for LDH and liver-specific ALT.

[0038] The aforementioned study ( 8 ) also reported that the addition of alanyl-glutamine to PDFs reduced systemic inflammation, reflected by a trend toward reduced biomarkers such as hs-CRP and IL-6, reaching statistical significance for IL-8 ( 8 , Table 3 ).

[0039] Our novel secondary analysis now further revealed significant associations between changes in a marker of systemic inflammation (interleukin-6) and changes in liver enzymes (GGT) and clinical markers of cytolysis (AST, LDH).

[0040] These findings also support our experimental findings in mouse models regarding the therapeutic effects of alanyl-glutamine on the regulation of cell death (e.g., necroptosis signaling) and systemic inflammation, particularly metabolic inflammation, and suggest that alanyl-glutamine acts on the liver, which is both a sentinel and a vector in PD patients.

[0041] Taken together, experimental findings and novel secondary data analyses of human clinical trials indicate that intraperitoneal treatment with alanyl-glutamine not only attenuates PD-induced liver inflammatory injury and liver-mediated systemic inflammation, particularly metabolic inflammation, in experimental systems, but also results in a reduction of clinically relevant parameters of liver injury and systemic inflammation in chronic PD patients.

[0042] In a further embodiment of the present invention, the ESKD-related disease (B) mediated by liver dysfunction is a cardiovascular disease, including inflammation-driven cardiovascular disease and metabolic inflammation-driven cardiovascular disease, in particular atherosclerotic cardiovascular disease.

[0043] As noted above, the liver is increasingly recognized as a central hub linking metabolism and CVD.

[0044] As discussed above, intraperitoneal treatment with alanyl-glutamine not only attenuates PD-induced liver inflammatory injury and liver-mediated systemic inflammation, particularly metabolic inflammation, in experimental systems, but also results in a reduction of clinically relevant parameters of liver injury and systemic inflammation in chronic PD patients.

[0045] The alleviation of novel side effects of PD by adding alanyl-glutamine to PDFs, as discovered by the inventors, provides a novel targeted therapeutic option in PD patients to improve systemic inflammation, particularly metabolic inflammation, and thereby improve CVD outcomes.

[0046] This novel treatment option may provide a suitable alternative to the administration of anti-inflammatory biologics such as IL-6-specific antibodies.

[0047] In one embodiment of the invention, administration of a protectant begins at the beginning of the peritoneal dialysis treatment.

[0048] In another embodiment of the invention, administration of the protectant is initiated a period of time after the initiation of said peritoneal dialysis treatment.

[0049] In this embodiment, administration can be initiated as soon as an indicator of liver disease or liver-mediated systemic inflammation, particularly metabolic inflammation, associated with peritoneal dialysis treatment is detected. Such indicators can be biomarkers, such as laboratory markers, and / or imaging findings.

[0050] Indicators of liver disease may include serum markers of hepatobiliary injury (e.g., AST, ALT, GGT, ALP, bilirubin) and / or imaging findings indicative of liver injury and / or hepatitis and / or fatty degeneration / deposition and / or fibrosis (e.g., MRI, CT, PET, hepatic elastography, ultrasound).

[0051] Indicators of inflammation / metabolic inflammation may also be observed, such as serum markers (e.g., CRP, hs-CRP, IL-6, IL-8, albumin, fibrinogen, SAA) and / or erythrocyte sedimentation rate and / or imaging findings (e.g., PET).

[0052] Similarly, biomarkers (e.g., CRP, hs-CRP, IL-6, IL-8, fibrinogen, SAA) and / or imaging findings (e.g., angiography, MRI, CT, PET, ultrasound) can be observed as indicators of cardiovascular disease, particularly inflammation / metabolic inflammation-driven cardiovascular disease.

[0053] According to the present invention, the protective agent is administered intraperitoneally so that it reaches the part of the human body that is directly affected by the PD treatment.

[0054] Intraperitoneal administration can be via intraperitoneal injection or infusion of the protectant in a suitable pharmaceutical carrier known to those skilled in the art.

[0055] Administration can be intermittent or continuous.

[0056] In a particularly preferred embodiment, the protectant is administered as a component of peritoneal dialysis fluid (PDF).

[0057] The PDF containing the protectant may preferably be the exact same PDF that is administered to patients for PD treatment.

[0058] In this case, the body, which has already undergone PD treatment, has not yet been exposed to an additional, different treatment solution.

[0059] The PDF containing the protectant may, in this embodiment, be administered from the start of the PD treatment (as the only PDF).

[0060] Alternatively, if treatment is initiated with a different peritoneal dialysis fluid, the other PDF may be completely replaced with a fluid containing a protective agent, particularly as soon as indicators of liver disease or liver-mediated systemic inflammation, particularly metabolic inflammation, are detected.

[0061] Preferably, the fluid containing the protectant is administered as the only PDF during the course of PD treatment, meaning that the patient is treated only with the PDF containing the protectant.

[0062] In another embodiment, the fluid may be administered in combination with another peritoneal dialysis fluid, which may be selected from any available PDF that is compatible with the PDF containing the protectant.

[0063] In a further embodiment of the invention, the PDF containing the protectant is based on glucose as the osmotic agent.

[0064] Preferably, the protective agent used according to or in the methods of the present invention is L-alanyl-L-glutamine, optionally mixed with one or more other protective agents. [Example]

[0065] Examples 1 and 2 Mouse test model method We performed mouse PD exposure experiments similar to chronic PD in healthy and uremic mice: The experiment consisted of n=34 animals in six separate groups.

[0066] The animals were divided into the following groups: 1) Healthy control animals (“controls”) 2) Healthy animals undergoing PD treatment (via an indwelling catheter) (“PD”) 3) healthy animals receiving PD treatment (via an indwelling catheter) supplemented with alanyl-glutamine ("PD+AG"); 4) Uremic animals (“uremia”) 5) Uremic animals undergoing PD treatment (via an indwelling catheter) (“Uremic PD”) 6) Uremic animals receiving PD treatment (via an indwelling catheter) supplemented with alanyl-glutamine ("Uremic PD+AG")

[0067] All animals in the uremic groups (groups 4, 5, and 6) were subjected to left 2 / 3 nephrectomy on day 0 of the study and right complete nephrectomy on day 7 of the study, thereby inducing chronic kidney disease.

[0068] All animals undergoing PD treatment (Groups 2, 3, 5, and 6) were implanted with indwelling catheters on day 7 of the study.

[0069] Animals in groups 2, 3, 5, and 6 received daily PDF (Dianeal PD4 3.86% [Baxter, Deerfield, IL, USA]) injections via an indwelling catheter over the course of 6 weeks from day 14, thereby inducing chronic PDF exposure.

[0070] For animals in groups 3 and 6, daily PDF injections were supplemented with alanyl-glutamine (8 mM) over the course of 6 weeks.

[0071] At the time of sacrifice (day 56 of the study), the livers of the animals were subjected to histological analysis.

[0072] NAFLD activity score (NAS) assessment was performed on hematoxylin and eosin (H&E)-stained liver tissue in one focal field image per mouse as previously described ( 47 ).

[0073] Hepatic steatosis was assessed by semiquantitative measurement of Oil Red O-stained liver tissue using one focused field image per mouse.

[0074] Liver fibrosis was assessed by semiquantitative measurement of Sirius Red-stained liver tissue using one focused field image per mouse. [Example]

[0075] PD induces liver injury regardless of uremic status - Alanyl-glutamine attenuates this effect of PD Liver histology on H&E staining at the end of the experiment showed an increased area of ​​hepatocyte ballooning in PD-treated animals, along with a marked increase in the number of inflammatory immune cell infiltrates, especially near the interlobular veins of the portal venous system (peritoneal outflow).

[0076] These findings are reflected by a significant increase in the NAFLD activity score (NAS) in mice treated with PD, as shown in FIG.

[0077] Figure 1a shows these changes in healthy animals, and Figure 1b shows these changes in a uremic animal model. In both panels, mice with PD showed a significant increase (p<0.05) in NAFLD activity score (NAS) compared with mice without PD.

[0078] Thus, this effect of PD was observed in both healthy and uremic animals, i.e., regardless of the uremic status. These increases in NAS were primarily caused by a higher number of inflammatory infiltrates.

[0079] On the other hand, the addition of alanyl-glutamine to PDFs resulted in a significant reduction in the number of inflammatory immune cell infiltrates and a reduction in the area of ​​hepatocyte ballooning in H&E liver sections, semiquantitatively expressed as a significant (p<0.05) decrease in NAS in uremic mice. Similarly, this is also primarily driven by the occurrence of inflammatory infiltrates (Figure 2a). Furthermore, a trend toward improvement in PD-induced hepatic steatosis (indicated by the % area of ​​Oil Red O-stained tissue, Figure 2b) and hepatic fibrosis (indicated by the % area of ​​Sirius Red-stained tissue, Figure 2c) could be observed with the addition of alanyl-glutamine to PDFs. [Example]

[0080] PD treatment induces hepatic inflammatory and acute-phase responses; again, alanyl-glutamine attenuates this effect To investigate the effects of hepatic molecular inflammatory responses induced by or associated with PD and to discover potential novel treatment interventions, the livers of all animals from the mouse study in Example 1 were subjected to mass spectrometry proteomic analysis.

[0081] We used Ingenuity Pathway Analysis (EMEA Qiagen, Aarhus, Denmark) to extract all identified proteins that were either part of the acute-phase response signaling pathway or part of pathways associated with hepatic inflammation. Of the subset of proteins identified by PLS-DA (Partial Least Squares-Discriminant Analysis) as most important for discriminating between livers of animals with and without PD, 57 were significantly (p<0.05, linear model with empirical Bayes shrinkage for variance stabilization) dysregulated by PD compared with control animals.

[0082] Supplementation of PDFs with alanyl-glutamine significantly altered the abundance of 11 of these acute-phase response and inflammation-related proteins in the livers of uremic animals treated with PD (p<0.05, linear model with empirical Bayes shrinkage for variance stabilization). These 11 proteins are part of the acute-phase response signaling (e.g., CFB, APOH, and RELA), glucocorticoid receptor signaling (e.g., HSPA5, NCOR1, NDUFA4, NDUFB3, SDHB, RELA, and IRF3), and necroptosis signaling (e.g., TIMM13, PPID, and IRF3) pathways.

[0083] FIG. 3 shows in graphical form this effect on three selected biomarkers (APOH, CFB, and CRP) known to have clinically meaningful associations with cardiovascular risk.

[0084] Thus, we demonstrate herein the distinct effects of PD on hepatic inflammation and liver-mediated systemic inflammation, particularly metabolic inflammation, and their amelioration at hepatic protein levels by alanyl-glutamine supplementation of PDFs.The effects of alanyl-glutamine supplementation of PDFs on PD-induced hepatic inflammation and liver-mediated systemic inflammation, particularly metabolic inflammation, were primarily achieved through modulation of proteins in the acute phase response signaling, glucocorticoid receptor signaling (regulation of NFκB and its respective downstream effects), and necroptosis signaling pathways. [Example]

[0085] Alanyl-glutamine supplementation of PDF improves liver function in human PD patients To further investigate the effect of alanyl-glutamine supplementation of PDFs on PD-induced liver dysfunction in humans, we performed a secondary analysis of a prospective, multicenter, double-blind, controlled, randomized, two-period, two-arm, crossover, phase II, proof-of-concept study involving eight Austrian centers on alanyl-glutamine supplementation of PDFs in chronic PD patients.

[0086] For this purpose, we included liver tests (GOT / AST, GPT / ALT, GGT, LDH) obtained as safety data in all patients in the full analysis set, because the adherence analysis excluded patients with interfering, local peritoneal effects alone. Consequently, n = 41 chronic PD patients were randomized to either the placebo-preceding or alanyl-glutamine-preceding arm of this crossover study for secondary analyses.

[0087] This study cohort and its baseline characteristics have already been described previously by Vychytil et al. (8)

[0088] Alanyl-glutamine supplementation of PDFs could significantly reduce clinical markers of liver injury. These effects of alanyl-glutamine in human studies in chronic PD patients are in good agreement with the effects of alanyl-glutamine on the regulation of cell death (e.g., necroptosis signaling) at the protein level in the mouse experiments described in Example 2.

[0089] The effect of alanyl-glutamine supplementation to PDF on markers of liver function (damage) is shown in Table 1 below.

[0090] [Table 1]

[0091] Furthermore, a positive correlation was observed between the changes in various clinical diagnostic markers of hepatobiliary injury induced by alanyl-glutamine supplementation of PDFs, as shown in panel a of Figure 4. Because each marker induces a different pattern of cellular injury within the hepatobiliary system, different levels of significance can be observed for each correlation pair.

[0092] Panel b shows a significant positive correlation between the change in one of the clinical diagnostic markers for hepatobiliary injury (GGT) and the change in a clinical diagnostic marker for inflammation (IL-6) induced by alanyl-glutamine supplementation of PDFs. As mentioned above, systemic administration of anti-inflammatory biologics, such as IL-6-specific antibodies, is currently being developed as a therapeutic option for treating metabolic inflammation and reducing the risk of CVD. Thus, Figure 4 correlates the observed reduction in clinical diagnostic markers for hepatobiliary injury by alanyl-glutamine supplementation of PDFs (Table 1, panel a of Figure 4) with the observed reduction in clinical diagnostic markers for inflammation, particularly / for example / metabolic inflammation (panel b of Figure 4). This serves as validation of the observed mechanistic effects of alanyl-glutamine in the mouse PD model of Examples 1 and 2 in a human clinical randomized, placebo-controlled Phase II trial.

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Claims

1. During peritoneal dialysis treatment, (A) liver disease induced by said peritoneal dialysis treatment, and / or (B) diseases associated with end-stage renal disease (ESKD) mediated by liver dysfunction induced by said peritoneal dialysis treatment 1. A protective agent selected from the group consisting of L-glutamine, L-alanyl-L-glutamine, L-glutaminyl-L-alanine, L-glutaminyl-L-glycine, L-glycinyl-L-glutamine, or mixtures thereof, for particular use in the prevention and / or treatment of administered by intraperitoneal injection, Protective agent.

2. The protective agent for use according to claim 1, wherein the liver disease (A) induced by peritoneal dialysis treatment is a chronic liver disease, in particular non-infectious hepatitis.

3. The protective agent for use according to claim 2, wherein the non-infectious hepatitis includes non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), and metabolic (dysfunction)-associated fatty liver disease (MAFLD).

4. The protective agent for use according to any one of claims 1 to 3, wherein the ESKD-related disease (B) mediated by liver dysfunction is a cardiovascular disease, including inflammation-driven cardiovascular disease and metabolic inflammation-driven cardiovascular disease, in particular atherosclerotic cardiovascular disease.

5. The protective agent for use according to any one of claims 1 to 4, wherein administration of the protective agent is initiated at the start of the peritoneal dialysis treatment.

6. The protective agent for use according to any one of claims 1 to 4, wherein administration of the protective agent is initiated a certain period of time after the start of the peritoneal dialysis treatment.

7. 7. The protective agent for use according to claim 6, wherein administration of the protective agent is initiated as soon as indicators of liver disease or liver-mediated inflammation, in particular metabolic inflammation, or cardiovascular disease are detected.

8. The protective agent for use according to claim 7, wherein the indicator is selected from the group consisting of biomarkers such as clinical test markers and / or imaging findings.

9. 9. The protective agent for use according to any one of claims 1 to 8, which is administered as a component of peritoneal dialysis fluid (PDF).

10. The protective agent for use according to claim 9, wherein the fluid is administered as the only PDF in the course of PD treatment.

11. The protective agent for use according to claim 9, wherein the fluid is administered in combination with another peritoneal dialysis fluid.

12. 12. The protective agent for use according to any one of claims 9 to 11, wherein the liquid is based on glucose as an osmotic agent.

13. 13. The protective agent for use according to any one of claims 1 to 12, which is L-alanyl-L-glutamine optionally mixed with one or more of the other protective agents.

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