Method for evaluating the severity of intestinal barrier damage based on blood and fecal ferritin detection

Abstract

The present invention relates to the field of medical detection technology, and discloses a method for evaluating the severity of intestinal barrier damage based on blood and fecal ferritin detection, including the preparation of ferritin content detection in blood and feces and ferritin as a marker that can be independently applied to intestinal barrier damage assessment and prediction of high-risk populations. The present invention provides a specific basis for risk prediction, prognosis and disease progression monitoring of patients with intestinal barrier damage, greatly advances the timing of clinical diagnosis and treatment decisions, fills the gap in medical industry research and clinical application, and has great potential and value for clinical and market applications.

Description

Technical Field

[0001] The present invention relates to the field of medical detection technology, and more specifically, to a method for evaluating the severity of intestinal barrier damage based on blood and fecal ferritin detection. Background Art

[0002] Intestinal barrier damage is a common clinical manifestation. However, its diagnosis is still mainly based on clinical symptom evaluation, such as abdominal pain, abdominal distension, nutritional intolerance, gastric retention, and decreased bowel sounds. However, these manifestations are often difficult to diagnose when patients have non-gastrointestinal diseases as primary diseases, and are easily overlooked by the clinic because of the masking of the primary disease symptoms. For example, patients with heart failure and shock often suffer from gastrointestinal ischemia and microcirculation disorders due to the reduction of effective circulating blood volume and the redistribution of systemic blood flow to ensure the blood supply of important organs of the heart and brain. However, patients are often in a coma or unclear consciousness due to severe illness and have difficulty expressing discomfort symptoms. By the time gastrointestinal damage is discovered, patients often have serious complications such as aspiration, gastrointestinal bleeding, increased intra-abdominal pressure, and enterogenic infection. This greatly increases the difficulty of treatment, prolongs hospitalization time, and increases the incidence of complications and medical expenses. Therefore, early and rapid evaluation of whether the intestine is damaged to assist clinicians in clinical diagnosis is necessary to achieve early detection, early treatment, and early treatment of intestinal damage.

[0003] At present, there are many markers for intestinal barrier damage, such as intestinal fatty acid binding protein (I-FABP), serum endotoxin detection, serum diamine oxidase, fecal calprotectin, D-lactic acid, inflammatory factors, etc. Although some of these indicators are enterocyte-specific proteins (such as I-FABP, diamine oxidase), and the levels detected in the blood are positively correlated with the degree of intestinal barrier damage, these indicators do not have clear definition values, and it is difficult to make abnormal judgments similar to blood routine tests through a single test, and the patient's baseline level is required as a reference; other indicators are designed based on the principle that when the intestinal barrier is damaged, the permeability increases and bacterial products can be released into the blood, but such indicators will also increase in systemic inflammation or systemic infection, making it difficult to clearly identify specific intestinal damage; and proteins such as calprotectin that originally exist in neutrophils are indicators of increased inflammatory bowel disease (a special type of intestinal disease), and are proteins expressed in large quantities by non-intestinal cells, so they are difficult to react to intestinal damage in non-inflammatory bowel disease.

[0004] Ferritin is a type of protein widely present in the body and is also the main protein for intracellular iron storage. In clinical practice, serum ferritin levels are often used to assess the iron storage of patients. Recent studies have found that ferritin expression levels are closely related to NF-κB signaling. Clinically, it has also been found that serum ferritin levels in patients with sepsis are elevated, and the ferritin levels in the death group are more significant (Boshuizen M, et al. Ann Intensive Care, 2018). Several animal studies have also shown that LPS and TNF-a can promote the expression of ferritin to bind intracellular iron and reduce oxidative stress damage (Pham CG, et al. Cell, 2004). Therefore, ferritin is secreted and increased by cells during infection, tumors, and inflammation, and ferritin is also expressed in large quantities in intestinal epithelial cells and released into the intestinal cavity when intestinal epithelial cells are damaged, resulting in increased fecal ferritin levels. Because ferritin will be released from cells under various stresses or diseases, using this characteristic to detect its content in the intestinal cavity can more sensitively reflect whether the intestine is damaged. This has a strong guiding significance for the evaluation of non-intestinal specific diseases, especially for various critically ill patients. But on the other hand, because it is more sensitive, the level of ferritin in plasma will also increase under conditions of stress inflammation. On the one hand, systemic damage will gradually affect the intestines and cause gastrointestinal damage, but because it is too sensitive, the increase in plasma ferritin will lead clinicians to attribute it to systemic damage, which may mask the extent of intestinal damage and delay the implementation of preventive measures for gastrointestinal damage in the treatment plan. By the time clinical symptoms of gastrointestinal damage appear, the disease has often entered the late stage, greatly increasing the difficulty of treatment and the complexity of the disease.

[0005] In order to improve the specific indicators of intestinal damage and eliminate the individual differences and systemic damage levels of different people, this program is designed to detect fecal ferritin and plasma ferritin levels, and multiply the two to correct the fecal ferritin level. This improves the predictive value of using plasma or fecal ferritin alone to evaluate intestinal damage. It can also evaluate the impact of systemic inflammation or infection on the intestine. Conversely, it can also evaluate the value of the degree of intestinal barrier damage to systemic inflammation, so as to better evaluate and predict intestinal barrier damage. Summary of the invention

[0006] In order to overcome the above-mentioned defects in the prior art, the present invention provides a method for evaluating the severity of intestinal barrier damage based on blood and fecal ferritin detection. The present invention includes two quantitative tests, namely plasma ferritin and fecal ferritin levels, which can be used alone for relevant evaluation. Including: quantitative detection of plasma levels, which can be used for single indicator evaluation. Plasma ferritin can be used for systemic inflammatory response, tumor indicator evaluation, severity of novel coronavirus infection and other systemic inflammatory response evaluation; quantitative detection of fecal ferritin can be used for inflammatory bowel disease, including Crohn's disease and ulcerative colitis, intestinal ischemic injury, gastrointestinal surgery perioperative intestinal injury and other intestinal specific injuries; after the two are combined, the fecal ferritin product can be used independently as a marker to evaluate the degree of injury in patients with intestinal barrier injury; it is proved that the fecal ferritin product has improved the ability to predict intestinal barrier injury compared with traditional markers, and can identify more "high-risk" people for intestinal injury; it is proved that continuous measurement of fecal ferritin product can be used to monitor disease progression and is not affected by systemic inflammation level or systemic infection; it provides a scientific basis for risk stratification, prognosis and disease progression monitoring for high-risk people with intestinal barrier injury, and can greatly advance the decision-making time for active clinical intervention before adverse events occur, and can be used to guide the timing of enteral nutrition initiation, the evaluation of gastrointestinal-related adverse events, the adjustment of treatment strategies, etc.; it fills the gap in medical industry research and clinical application, and has great potential and value for clinical and market applications.

[0007] The above technical objectives of the present invention are achieved through the following technical solutions: A method for evaluating the severity of intestinal barrier damage based on blood and fecal ferritin detection, comprising the following steps:

[0008] S1. Collect a stool sample. Use a stool sample spoon to take 5 mg of stool into a centrifuge tube. Place it at 4°C, add 500 uL of lysis solution, and vortex to mix until no stool particles are visible to the naked eye to obtain a stool protein extract.

[0009] S2, using a pipette to dispense the fecal protein extract, and placing the fecal protein extract in a fecal protein extract storage tube;

[0010] S3, using a test kit to detect the ferritin content in feces;

[0011] S4. Collect 3 mL of whole blood sample using EDTA anticoagulant tube, centrifuge at 3000 g for 5 min, and use a pipette to draw the upper plasma sample;

[0012] S5. Detect the ferritin content in plasma using a detection kit;

[0013] S5. Detect plasma and fecal ferritin levels, calculate the corrected ferritin level, and combine it with clinical symptoms and signs to assess the degree of intestinal damage.

[0014] Furthermore, the detection kit may be an enzyme-linked immunosorbent assay kit containing ferritin antibodies, a chemiluminescence assay kit containing ferritin antibodies, a time-resolved fluorescence immunoassay kit containing ferritin antibodies, or a flow fluorescence assay kit containing ferritin antibodies.

[0015] In summary, the present invention has the following beneficial effects:

[0016] 1. The present invention contains two quantitative tests, namely plasma ferritin and fecal ferritin levels, which can be used alone or for related evaluations. Including: quantitative detection of plasma levels, which can be used for single indicator evaluation, plasma ferritin can be used for systemic inflammatory response, tumor indicator evaluation, the severity of new coronavirus infection and other systemic inflammatory responses; quantitative detection of fecal ferritin can be used for inflammatory bowel disease, including Crohn's disease and ulcerative colitis, intestinal ischemic damage, gastrointestinal surgery perioperative intestinal damage and other intestinal specific injuries.

[0017] 2. The present invention is the first to demonstrate that the fecal ferritin product can be independently used to assess the degree of damage in patients with intestinal barrier damage after correcting fecal ferritin.

[0018] 3. The present invention is the first to demonstrate that the fecal blood ferritin product improves the ability to predict intestinal barrier damage compared with traditional markers and can identify more "high-risk" populations.

[0019] 4. The present invention demonstrates for the first time that continuous measurement of fecal blood ferritin product can be used to monitor disease progression and reduce the impact of systemic inflammation levels or systemic infection conditions.

[0020] Therefore, the present invention provides a scientific basis for risk stratification, prognosis and disease progression monitoring for high-risk groups of intestinal barrier damage, and can greatly advance the decision-making time for active clinical intervention before adverse events occur, and can be used to guide the timing of initiating enteral nutrition, the evaluation of adverse events, the adjustment of treatment strategies, etc. It fills the gap in medical industry research and clinical application, and has great potential and value for clinical and market applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of a research process in an embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram showing the correlation between the patient's plasma ferritin level and the disease severity (SOFA score) according to an embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram showing the correlation between the fecal ferritin level of a patient and the degree of intestinal barrier damage according to an embodiment of the present invention;

[0024] Figure 4A schematic diagram of a KM curve drawn for differences in patient survival curves at different levels of plasma ferritin in an embodiment of the present invention;

[0025] Figure 5 The ROC curve of the prediction analysis of patient mortality using plasma ferritin in an embodiment of the present invention;

[0026] Figure 6 The ROC curves for comparing the prediction of AGI occurrence by corrected ferritin and common intestinal injury markers in the embodiments of the present invention. DETAILED DESCRIPTION

[0027] In the present invention, unless otherwise specified, the scientific and technical terms used herein have the meanings commonly understood by those skilled in the art. In addition, the reagents, materials and operating procedures used herein are reagents, materials and conventional procedures widely used in the corresponding fields. At the same time, in order to better understand the present invention, the definitions and explanations of the relevant terms are provided below.

[0028] Plasma: The part of blood other than formed elements. It accounts for about 5% of body weight and is the main carrier for transporting nutrients and metabolites. It is the light yellow first layer of supernatant after centrifugation or standing to separate blood in an anticoagulated state.

[0029] Ferritin: Iron storage protein, widely found in animal and plant tissues, composed of 24 polypeptide chains (subunits) forming a hollow spherical shell, the central cavity of which can accommodate 4500 iron atoms (trivalent), the iron inside is in a soluble and usable form, mainly bound to hydroxyl and phosphate groups. Low plasma ferritin levels are a characteristic of iron storage deficiency diseases.

[0030] SOFA score: A method proposed by the European Society of Critical Care Medicine at a special academic conference in Paris, France in October 1994 to describe a series of complications in critically ill patients. It is a scoring system to characterize the severity of the disease in critically ill patients. The higher the total score, the more serious the condition. It is still used today and widely used in clinical practice. The full name is: sepsis-related organ failure assessment, sepsis-related organ failure assessmentmen, which includes: limiting the number of organs included in the organ dysfunction or failure assessment system to 6, namely the respiratory system (oxygenation index), blood system (platelet count), liver (bilirubin level), cardiovascular system (hypotension), nervous system (GCS score) and kidney (creatinine or urine volume); each organ has a score of 0 (normal) to 4 points (worst); the worst value is recorded once a day.

[0031] AGI: Grading of acute gastrointestinal injury. In 2012, the European Society of Intensive Care Medicine's Abdominal Problems Working Group formulated and issued recommendations on the diagnosis and treatment of gastrointestinal function in critically ill patients based on evidence-based medicine, current knowledge and research results on the pathophysiology of gastrointestinal failure, and expert opinions. Since the failure of any organ is a dynamic development process, the occurrence of gastrointestinal failure is also the result of the gradual progression of the disease after injury. A new concept of AGI and related term definitions are proposed, and AGI grading diagnosis and treatment are recommended. (1) AGI grade I (presence of risk factors for gastrointestinal dysfunction or failure): defined as a clear cause and partial impairment of gastrointestinal function. It is temporary and self-limiting. Clinically, it is common in nausea, vomiting and disappearance of bowel sounds after abdominal surgery; weakened intestinal motility in the early stage of shock. For example: nausea, vomiting and disappearance of bowel sounds after abdominal surgery; weakened intestinal motility in the early stage of shock. (2) AGI grade II (gastrointestinal dysfunction): defined as gastrointestinal digestion and absorption dysfunction, which cannot meet the body's needs for nutrients and water, but has not yet affected the patient's general condition. It is characterized by the occurrence of acute gastrointestinal symptoms, which require certain intervention measures to meet the body's needs for nutrition and water. Clinically, it may manifest as gastroparesis with massive gastric retention or reflux, lower gastrointestinal paralysis, diarrhea, IAH grade I (IAP 12-15 mmHg), visible bleeding in gastric contents or stool, and food intolerance. (3) AGI grade III (gastrointestinal failure): defined as loss of gastrointestinal function. After intervention, gastrointestinal function still does not recover, and the systemic condition does not improve. For example, after active treatment (erythromycin, post-pyloric tube placement, etc.), food intolerance continues to not improve, and multiple organ dysfunction persists or progressively worsens. Clinically, it may manifest as massive gastric retention, persistent gastrointestinal paralysis, intestinal dilatation, intra-abdominal hypertension progressing to grade II (IAP 16-20 mmHg), and decreased peritoneal perfusion pressure (<60 mmHg). (4) AGI Grade IV (gastrointestinal failure with remote organ dysfunction): AGI progresses to a state that is directly life-threatening. The patient's MODS and shock worsen and are in danger of death at any time. The patient's general condition deteriorates rapidly, accompanied by remote organ dysfunction, such as intestinal ischemic necrosis, gastrointestinal bleeding leading to hemorrhagic shock, Ogilvies syndrome (acute colon pseudo-obstruction), and abdominal compartment syndrome requiring active decompression.

[0032] Kaplan-Meier method (KM curve): also known as product-limit method, suitable for small sample data. The basic idea is to arrange the survival time from small to large, and at each death point, calculate the initial number of people, number of deaths, death probability, survival probability and survival rate. Its idea is the same as the life table method, except that the division of time periods in the life table method is artificial and equidistant, while the division point of the time period in the product-limit method is the actual time of death.

[0033] ROC curve: receiver operating characteristic curve. Also known as sensitivity curve, it is the core indicator for evaluating the performance discrimination of medical diagnostic tests and prediction models. It is a curve that reflects the relationship between sensitivity and specificity. The horizontal axis X-axis is 1-specificity, also known as false positive rate (false alarm rate). The closer the X-axis is to zero, the higher the accuracy; the vertical axis Y-axis is called sensitivity, also known as true positive rate (sensitivity). The larger the Y-axis is, the better the accuracy is. According to the position of the curve, the entire graph is divided into two parts. The area under the curve is called AUC (area under curve), which is used to indicate the prediction accuracy. The higher the AUC value, that is, the larger the area under the curve, the higher the prediction accuracy. The closer the curve is to the upper left corner (the smaller the X, the larger the Y), the higher the prediction accuracy.

[0034] The following is combined with Figure 1-6 The present invention is described in further detail.

[0035] Embodiment: A method for assessing the severity of intestinal barrier damage based on blood and fecal ferritin detection comprises the following steps:

[0036] S1. Collect a stool sample. Use a stool sample spoon to take 5 mg of stool into a centrifuge tube. Place it at 4°C, add 500 uL of lysis solution, and vortex to mix until no stool particles are visible to the naked eye to obtain a stool protein extract.

[0037] S2, using a pipette to dispense the fecal protein extract, and placing the fecal protein extract in a fecal protein extract storage tube;

[0038] S3, using a test kit to detect the ferritin content in feces;

[0039] S4. Collect 3 mL of whole blood sample using EDTA anticoagulant tube, centrifuge at 3000 g for 5 min, and use a pipette to draw the upper plasma sample;

[0040] S5. Detect the ferritin content in plasma using a detection kit;

[0041] S5. Detect plasma and fecal ferritin levels, calculate the corrected ferritin level, and combine it with clinical symptoms and signs to assess the degree of intestinal damage.

[0042] The detection kit may be an enzyme-linked immunosorbent assay kit containing ferritin antibodies, a chemiluminescence assay kit containing ferritin antibodies, a time-resolved fluorescence immunoassay kit containing ferritin antibodies, or a flow fluorescence assay kit containing ferritin antibodies.

[0043] like Figure 1The figure is a schematic diagram of the research process in the embodiment of the invention.

[0044] In this embodiment, the research subjects are selected as critically ill patients with combined gastrointestinal damage, and healthy volunteers. The observation content includes basic clinical information: gender, age, BMI, disease severity assessment, and liver and kidney function test results. The non-clinical indicator detection method for plasma and fecal samples is ELISA. All detection equipment and kits used can be purchased domestically, and there is no special treatment method. The relevant basic clinical information is shown in Table 1-1, and the population is further divided into two basic pairs according to whether the severity of AGI requires intervention: the presence or absence of AGI and AGI grade I (Group A) and AGI grade II-IV (Group B). The differences between the two groups are shown in Table 1-2.

[0045] Table 1-1

[0046] Basic clinical information All patients (N=34) Age (years) 47.21±17.98 Gender (n,%) 25(73.5) <![CDATA[BMI(kg / m 2 )]]> 22.46±3.1 Body temperature(℃) 36.82±0.54 Systolic blood pressure (mmHg) 125.80±16.35 Diastolic blood pressure (mmHg) 76.73±11.46 Pulse pressure difference (mmHg) 76.73±11.46 Mean arterial pressure (mmol / L) 6.35±2.26 Heart rate (beats / min) 89.32±14.50 Respiratory rate (times / min) 20.68±4.10 APACHEII score (points) 10.35±8.92 SOFA score (points) 5.00±5.39 Total bilirubin (umol / L) 68.44±99.15 Serum creatinine (umol / L) 100.64±101.10 White blood cell count (10^9 / L) 11.80±7.68 Procalcitonin (ng / mL) 6.46±12.89 High-sensitivity C-reactive protein (mg / L) 118.16±83.68

[0047] Table 1-2

[0048] Basic clinical information Group A (N=16) Group B (N=18) P-value Age (years) 41.44±17.16 53.12±17.78 0.06 Gender (Male,%) 11(68.8) 13(72.2) 0.62 <![CDATA[BMI(kg / m 2 )]]> 21.95±2.74 22.81±3.50 0.46 Body temperature(℃) 36.75±0.57 36.84±0.49 0.65 Systolic blood pressure (mmHg) 118.31±16.96 126.06±20.28 0.24 Diastolic blood pressure (mmHg) 73.75±8.27 70.65±12.78 0.42 Pulse pressure difference (mmHg) 45.19±12.03 55.41±13.44 0.03 Mean arterial pressure (mmol / L) 88.81±9.92 89.12±14.34 0.94 Heart rate (beats / min) 82.31±9.62 94.18±14.74 0.11 Respiratory rate (times / min) 19.31±2.50 21.53±4.78 0.11 APACHEII score (points) 4.25±5.45 15.35±7.91 <0.001 SOFA score (points) 1.25±1.57 8.18±5.54 <0.001 Total bilirubin (umol / L) 24.22±15.22 107.94±127.91 0.02 Serum creatinine (umol / L) 79.18±95.25 122.04±107.71 0.24 White blood cell count (10^9 / L) 9.54±3.96 14.19±9.73 0.09 Procalcitonin (ng / mL) 1.48±2.75 11.14±16.95 0.03 High-sensitivity C-reactive protein (mg / L) 75.94±76.21 153.35±74.33 <0.01

[0049] Table 1-1 shows the clinical baseline characteristics of all participants. Table 1-2 shows that according to the proportion of people and whether the severity of AGI requires intervention, those without AGI and AGI grade I are divided into group A, and the rest are group B. Comparison of the differences in basic clinical information between the two groups shows that the disease severity scores APACHE II and SOFA scores are significantly correlated with AGI, followed by significant differences in high-sensitivity C-reactive protein, total bilirubin, and procalcitonin, indicating that higher levels of inflammation and disease severity are associated with higher AGI levels.

[0050] To further evaluate the correlation between plasma ferritin levels and disease severity, the results were as follows Figure 2 As shown, the horizontal axis is the severity of the disease (SOFA score), and the vertical axis is the plasma ferritin level. In this embodiment, the ELISA method is used to determine the ferritin level in plasma. The general steps are: add samples and standard products according to the requirements of the purchased human ferritin ELISA kit, incubate, wash, develop colors, etc., use an enzyme marker to measure the absorbance (OD value) at a wavelength of 450nm, and calculate the ferritin concentration in the sample according to the standard curve. Figure 2 This is a schematic diagram showing the correlation between the patient's plasma ferritin level and the severity of the disease (SOFA score) according to an embodiment of the present invention. The results indicate that the plasma ferritin level is positively correlated with the severity of the disease and can be used to evaluate, predict and assess the severity of the disease.

[0051] To further evaluate the relationship between fecal ferritin levels and the degree of intestinal barrier damage, Figure 3As shown in the figure, the correlation analysis between the fecal ferritin level and the degree of intestinal barrier damage of the patient is shown in the embodiment of the present invention. The degree of intestinal barrier damage is reflected by four common index levels: I-FABP, plasma MDA, inflammatory factor IL-6 in plasma, and AGI score. The correlation between the degree of intestinal barrier damage and these four indicators is analyzed. Figure 3 The results showed that ferritin levels had a good correlation with intestinal injury markers, and its levels were positively correlated with various injury markers, proving that it can be used as an intestinal injury marker to evaluate and predict intestinal barrier damage.

[0052] To further evaluate whether plasma ferritin is not only related to the severity of the disease but also closely related to the patient's prognosis, the Kaplan-Meier method was used to evaluate the correlation between high and low levels of ferritin and poor prognosis during the follow-up period. Figure 4 , which is a schematic diagram of the KM curve drawn for the differences in patient survival curves at different plasma ferritin levels in the embodiment of the present invention; indicating that the high-level ferritin group has a shorter survival time and a higher mortality rate than the low-level ferritin group. It proves that the plasma ferritin level can be used to predict the adverse outcome of patients.

[0053] In order to further evaluate the predictive efficacy of plasma ferritin levels for adverse outcomes, the ROC analysis method was used to evaluate its predictive efficacy for patient death outcomes using the area under the curve, i.e., AUC level. The results are shown in Figure 5 , which is the ROC curve of the prediction analysis of patient mortality using plasma ferritin in the embodiment of the present invention; the area under the curve can reach 0.899, P=0.003, indicating that its predictive value is better.

[0054] Similarly, to further evaluate the predictive efficacy of fecal ferritin levels and corrected ferritin levels for intestinal barrier damage, the ROC analysis method was used to evaluate the predictive efficacy of whether AGI occurred in patients using the area under the curve, i.e., AUC level. The analysis here was based on the presence or absence of AGI. Figure 6 , which is a comparison of the fecal ferritin levels before and after correction with other common intestinal barrier damage markers in the embodiment of the present invention. The degree of intestinal barrier damage is measured by I-FABP and the inflammatory factor IL-6 in plasma, and the ROC curve of each indicator for AGI prediction is analyzed. The AUC of plasma ferritin is 0.870, P = 0.002; the AUC of fecal ferritin is 0.880, P = 0.001; the AUC of ferritin after correction is 0.915, P < 0.0001; the AUC of I-FABP is 0.798, P = 0.012; the AUC of IL-6 is 0.848, P = 0.004. The results suggest that ferritin has a good ability to predict AGI regardless of whether it is corrected or not, and the effectiveness is better after correction.

[0055] In summary, plasma ferritin levels can be used as one of the evaluation criteria for disease severity, especially in systemic diseases and critical illnesses. Fecal ferritin levels are significantly correlated with intestinal damage, both in AGI clinical symptom scores and intestinal damage biomarkers. It can be used as an effective indicator for predicting the occurrence of AGI, with a high predictive efficiency. After further correction based on plasma levels, its predictive efficiency for AGI is improved compared to single use.

[0056] The present invention provides a method for detecting the content of plasma and fecal ferritin. Plasma ferritin can be used for the evaluation of systemic inflammatory responses, tumor index evaluation, severity of novel coronavirus infection, and other systemic inflammatory responses; fecal ferritin can be used for inflammatory bowel disease, including Crohn's disease and ulcerative colitis, intestinal ischemic damage, gastrointestinal surgery perioperative intestinal damage and other intestinal specific injuries. The corrected ferritin level can provide a scientific basis for risk stratification, prognosis and disease progression monitoring for high-risk groups of intestinal barrier damage, and can greatly advance the decision-making time for active clinical intervention before adverse events occur. It can be used to guide the timing of initiating enteral nutrition, the evaluation of adverse events, the adjustment of treatment strategies, etc. It fills the gap in research and clinical application in the medical industry, and has great potential and value for clinical and market applications.

[0057] This specific embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed. However, as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

Claims

1. Use of a reagent for detecting blood and fecal ferritin in preparing a kit for use in a method for assessing the severity of intestinal barrier damage, characterized in that: The method comprises the following steps: S1. Collect a stool sample. Use a stool sample spoon to take 5 mg of stool into a centrifuge tube. Place it at 4°C, add 500uL of lysis solution, and vortex to mix until no stool particles are visible to the naked eye to obtain a stool protein extract. S2, using a pipette to dispense the fecal protein extract, and placing the fecal protein extract in a fecal protein extract storage tube; S3. Detecting the ferritin content in the feces using a detection kit, wherein the detection kit may be an enzyme-linked immunosorbent assay kit containing ferritin antibodies, a chemiluminescence assay kit containing ferritin antibodies, a time-resolved fluorescence immunoassay kit containing ferritin antibodies, or a flow fluorescence assay kit containing ferritin antibodies; S4. Collect 3 mL of whole blood sample using EDTA anticoagulant tube, centrifuge at 3000 g for 5 min, and use a pipette to draw the upper plasma sample; S5. Detect the ferritin content in plasma using a detection kit; S6. Detect plasma and fecal ferritin levels, and calculate the corrected ferritin level. The corrected ferritin level is obtained by multiplying the fecal ferritin level with the plasma ferritin level. Combined with clinical symptoms and signs, the degree of intestinal damage is assessed.

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