Fecal calprotectin is a useful screening parameter for hepatic encephalopathy and spontaneous bacterial peritonitis in cirrhosis

Biomarkers in inflammatory bowel disease: a practical guide

Inflammatory bowel disease (IBD), comprising ulcerative colitis (UC) and Crohn's disease (CD), is a costly condition in terms of morbidity and healthcare utilization, with an increasing prevalence now approaching 1% in the Western world. Endoscopic assessment of IBD remains the gold standard for diagnosis, evaluation of treatment response and determination of post-operative recurrence, but is expensive and invasive. Biomarkers can facilitate non-invasive disease assessment, with C-reactive protein and faecal calprotectin as the most widely available biomarkers in current clinical practice. This narrative review summarizes the evidence for their use in both UC and CD and offers practical guidance for healthcare providers taking into account the limitations of biomarker interpretation. We present evidence for the future use of novel biomarkers in IBD and discuss how biomarker discovery could deliver the goal of precision medicine in IBD.

Systematic review of the role of calprotectin in cirrhosis

BACKGROUND

Calprotectin is a calcium-binding-S100-protein synthetized mainly in neutrophils which has been demonstrated to be an accurate biomarker of the presence of these cells. Gut barrier dysfunction in patients with advanced chronic liver disease (ACLD), in addition to the lack of noninvasive tools for diagnosis and prognosis of cirrhosis decompensations, has raised interest in this biomarker.

AIMS

Our aim is to summarize the current evidence regarding the role of calprotectin in terms of its diagnostic and prognostic utility in ACLD.

METHODS

We performed a systematic search (PROSPERO registration no. CRD42023389069) of original articles published without any restrictions on the publication date until January 2023 providing information about calprotectin for the prognosis or diagnosis of ACLD and its decompensations in adult patients.

RESULTS

A total 227 articles were identified, and 26 observational studies finally met the inclusion criteria. In 14 studies, calprotectin was measured in ascitic fluid, all of which reported higher calprotectin values in spontaneous bacterial peritonitis, while cut-off points for its diagnosis were proposed in nine studies. Three studies reported higher faecal calprotectin levels in patients with hepatic encephalopathy and portal hypertension. Four studies evaluated faecal calprotectin and one plasma calprotectin as biomarkers for gut barrier integrity and bacterial translocation.

CONCLUSIONS

Calprotectin is emerging as a promising biomarker in ACLD, particularly for the management of bacterial infections and alcohol-related liver disease. Further research with better study designs should help to determine the feasibility of calprotectin measurement in routine clinical practice.

Fecal calprotectin in patients with liver cirrhosis

BACKGROUND AND OBJECTIVES

Sepsis is the most challenging complication in patients with liver cirrhosis. It destabilizes patients leading to worsening of liver dysfunction and increased mortality. Intestinal bacterial dysbiosis, release of endotoxins, increased gut permeability and associated immune dysregulation have been described in cirrhotic patients with septic complications. Calprotectin is a major cytosolic protein secreted by the inflammatory cells and has been widely studied in patients with inflammatory bowel disease. We aimed at evaluating the role of fecal calprotectin (FCAL) in patients with liver cirrhosis.

METHODS

A prospective, observational study on the utility of FCAL test was conducted in patients with liver cirrhosis. Fifteen milligrams of fecal specimen was collected and analyzed within 48 hours of hospitalization from patients with end-stage liver disease (ESLD), acute-on-chronic liver failure (ACLF) and at the time of outpatient visit for stable cirrhotics. Five healthy volunteers underwent FCAL test as control population.

RESULTS

The mean FCAL (µg/g) level in healthy control (n = 5), stable cirrhotics (n = 10), ESLD (n = 10) and ACLF (n = 10) patients was 109.2 (95% CI: - 53.39 to 271.79), 143.3 (95% CI: 50.5-236.45), 176.9 (95% CI: 122.93-230.87) and 543.5 (95% CI: 207.09-879.91) (p = 0.005), respectively. Sepsis was identified in 13 (43.3%) patients. Area under the receiver-operating characteristics curve (AUROC) of FCAL was 0.80 (p = 0.005) and FCAL ≥ 200 µg/g (OR = 10.8, p = 0.006) was associated with sepsis. Nine (25.7%) patients expired. FCAL level was significantly higher in dead patients compared to survivors (mean, 493.67 (95% CI: 142.20-845.14) vs. 199.71 (95% CI: 99.84-299.59) μg/g,p = 0.005.

CONCLUSIONS

FCAL levels are increased in patients with chronic liver disease, with highest level in ACLF. An FCAL level of ≥ 200 µg/g was associated with sepsis and mortality in cirrhotic patients. Larger studies are required to identify the role of FCAL in these patients. Early identification and initiation of anti-microbials may mitigate sepsis and reduce mortality.

Fecal calprotectin level as a marker of esophageal varices in Egyptian HCV cirrhotic patients

INTRODUCTION AND AIM

Esophageal varices are one of the complications of portal hypertension in cirrhotic patients that lead to high morbidity and mortality. Our aim was to assess the fecal calprotectin (FC) level in Egyptian cirrhotic patients as a non-invasive marker for the presence of esophageal varices.

MATERIALS AND METHODS

The current study included 250 participants in the period from June 2019 to November 2020, divided into three groups: group 1: 100 HCV cirrhotic patients with esophageal varices that would then be subdivided, according to the Paquet classification; group 2: 100 HCV cirrhotic patients without esophageal varices; group 3: 50 normal age and sex-matched healthy subjects as the control group. Patients with other causes of abnormal calprotectin results were excluded.

RESULTS

The comparison of FC in the three study groups revealed a statistically significant difference, with FC levels higher in groups 1 and 2 (mean 66.4±10.41 and 48.4±10.92, respectively). There was a significant difference in FC levels between the subgroups, subdivided according to the Paquet classification (P=.001). FC levels were higher in the grade III and IV subgroups. FC in the diagnosis of HCV cirrhotic patients with esophageal varices showed the best performance when the cut-off value was >55; AUC was 0.918, with 92% sensitivity, 95% specificity, and 93% accuracy.

CONCLUSION

FC levels serve as a screening tool for esophageal varices. FC was higher in cirrhotic patients with esophageal varices, especially in the grade III and IV subgroups, according to the Paquet classification.

Elevated calprotectin levels are associated with mortality in patients with acute decompensation of liver cirrhosis

BACKGROUND

Acute decompensation (AD) of cirrhosis is related to systemic inflammation and elevated circulating cytokines. In this context, biomarkers of inflammation, such as calprotectin, may be of prognostic value.

AIM

To evaluate serum calprotectin levels in patients hospitalized for complications of cirrhosis.

METHODS

This is a prospective cohort study that included 200 subjects hospitalized for complications of cirrhosis, 20 outpatients with stable cirrhosis, and 20 healthy controls. Serum calprotectin was measured by enzyme-linked immunosorbant assay.

RESULTS

Calprotectin levels were higher among groups with cirrhosis when compared to healthy controls. Higher median calprotectin was related to Child-Pugh C, ascites, and hepatic encephalopathy. Higher calprotectin was related to acute-on-chronic liver failure (ACLF) and infection in the bivariate, but not in multivariate analysis. Calprotectin was not associated with survival among patients with ACLF; however, in patients with AD without ACLF, higher calprotectin was associated with a lower 30-d survival, even after adjustment for chronic liver failure-consortium (CLIF-C) AD score. A high-risk group (CLIF-C AD score ≥ 60 and calprotectin ≥ 580 ng/mL) was identified, which had a 30-d survival (27.3%) similar to that of patients with grade 3 ACLF (23.3%).

CONCLUSION

Serum calprotectin is associated with prognosis in patients with AD without ACLF and may be useful in clinical practice to early identify patients with a very low short-term survival.

Expansion of Opportunistic Enteric Fungal Pathogens and Occurrence of Gut Inflammation in Human Liver Echinococcosis

Increasing evidence shows that the gut fungal mycobiota is implicated in human disease. However, its relationship with chronic helminth infections, which cause immunosuppression and affect over 1 billion people worldwide, remains unexplored. In this study, we investigated the gut mycobiome and its associations with gut homeostasis in a severe helminth disease worldwide: liver echinococcosis. Fecal samples from 63 patients and 42 healthy controls were collected to characterize the fungal signatures using ITS1 sequencing, QIIME pipeline, and machine learning analysis. The levels of fecal calprotectin and serological anti-Saccharomyces cerevisiae antibodies (ASCA) in these subjects were experimentally measured. We found that fungal microbiota was significantly skewed in disease, with an overrepresentation of Aspergillus, Candida, Geotrichum, Kazachstania, and Penicillium and a decrease of Fusarium. Machine learning analysis revealed that the altered fungal features could efficiently predict infection with high sensitivity and specificity (area under the curve [AUC] = 0.93). The dysbiosis was characterized by expansions of multiple opportunistic pathogens (Aspergillus spp. and Candida spp.). Clinical association analysis revealed that host immunity might link to the expansions of the invasive fungi. Accompanying the opportunistic pathogen expansion, the levels of fungi-associated fecal calprotectin and serological ASCA in the patients were elevated, suggesting that gut inflammation and microbiota translocation occurred in this generally assumed extraintestinal disease. This study highlights enteric fungal pathogen expansions and increased levels of markers for fungi-associated mucosal inflammation and intestinal permeability as hallmarks of liver echinococcosis. IMPORTANCE Helminth infection affects over 1 billion people worldwide. However, its relationship with the gut mycobiome remains unknown. Among the most prevalent helminth diseases, human hydatid disease (echinococcosis) is highlighted as one of the most important (second/third for alveolar/cystic echinococcosis) foodborne parasitic diseases at the global level. Herein, we investigated the mycobiome and gut homeostasis (i.e., inflammation and permeability) in human echinococcosis. Our results revealed that fungal dysbiosis with an expansion of opportunistic pathogens and increased levels of fecal calprotectin and serum ASCA are hallmarks of human liver echinococcosis. Host immunity is associated with enteric fungal expansions. These findings suggest that an extraintestinal helminth infection is able to alter gut fungal microbiota and impair gut homeostasis, which resembles concomitant gut symptoms in inflammatory gut-related diseases (e.g., AIDS). In clinical practice, physicians need to take cautious medical consideration of gut health for nonintestinal helminth diseases.

New Faecal Calprotectin Assay by IDS: Validation and Comparison to DiaSorin Method

Background: The faecal calprotectin (FC) measurement is used for inflammatory bowel disease (IBD) diagnosis and follow-up. The aim of this study was to validate for the first time the new IDS FC extraction device and immunoassay kit, and to compare it with the DiaSorin test in patients with and without IBD. Methods: First, the precision of the IDS assay and its stability were assessed. Then, 379 stool extracts were analysed with the IDS kit on iSYS and compared with a DiaSorin Liaison XL assay. Results: The intra- and inter-assay CVs did not exceed 5%. The stool samples were stable up to 4 weeks at −20 °C. Lot-to-lot comparison showed a good correlation (Lot1 = 1.06 × Lot2 + 0.60; p > 0.05). The Passing and Bablok regression showed no significant deviation from linearity between the two methods (IDS = 1.06 × DiaSorin − 0.6; p > 0.05; concordance correlation coefficient = 0.93). According to the recommended cut-offs, the IDS assay identified more IBD and irritable bowel syndrome patients than DiaSorin, which had more borderline results (16 vs. 20%, respectively). Conclusions: The IDS faecal calprotectin had good analytical validation parameters. Compared to the DiaSorin method, it showed comparable results, but slightly outperformed it in the identification of more IBD patients and active disease.

Spontaneous Bacterial Peritonitis in Decompensated Liver Cirrhosis—A Literature Review

Background: Spontaneous bacterial peritonitis (SBP) is defined as a bacterial infection of the ascitic fluid without a surgically treatable intra-abdominal infection source. SBP is a common, severe complication in cirrhosis patients with ascites, and if left untreated, in-hospital mortality may exceed 90%. However, the incidence of SBP has been lowered to approx. 20% through early diagnosis and antibiotic therapy. Clinical awareness, prompt diagnosis, and immediate treatment are advised when caring for these patients to reduce mortality and morbidity. Aim: To discuss important issues comprising types of SBP, pathogenesis, bacteriology, including the emergence of multidrug-resistant (MDR) microorganisms, prompt diagnosis, risk factors, prognosis, treatment strategies, as well as recurrence prevention through antibiotic prophylaxis until liver transplantation and future trends in treating and preventing SBP in detail. Methods: This article is a literature review and appraisal of guidelines, randomized controlled trials, meta-analyses, and other review articles found on PubMed from between 1977 and 2022. Results: There are three types of SBP. Bacterial translocation from GI tract is the most common source of SBP. Therefore, two thirds of SBP cases were caused by Gram-negative bacilli, of which Escherichia coli is the most frequently isolated pathogen. However, a trend of Gram-positive cocci associated SBP has been demonstrated in recent years, possibly related to more invasive procedures and long-term quinolone prophylaxis. A diagnostic paracentesis should be performed in all patients with cirrhosis and ascites who require emergency room care or hospitalization, who demonstrate or report consistent signs/symptoms in order to confirm evidence of SBP. Distinguishing SBP from secondary bacterial peritonitis is essential because the conditions require different therapeutic strategies. The standard treatment for SBP is prompt broad-spectrum antibiotic administration and should be tailored according to community-acquired SBP, healthcare-associated or nosocomial SBP infections and local resistance profile. Albumin supplementation, especially in patients with renal impairment, is also beneficial. Selective intestinal decontamination is associated with a reduced risk of bacterial infection and mortality in high-risk group. Conclusions: The standard treatment for SBP is prompt broad-spectrum antibiotic administration and should be tailored according to community-acquired SBP, healthcare-associated or nosocomial SBP infections and local resistance profile. Since the one-year overall mortality rates for SBP range from 53.9 to 78%, liver transplantation should be seriously considered for SBP survivors who are good candidates for transplantation. Further development of non-antibiotic strategies based on pathogenic mechanisms are also urgently needed.

Individuals with Metabolic Syndrome Show Altered Fecal Lipidomic Profiles with No Signs of Intestinal Inflammation or Increased Intestinal Permeability

BACKGROUND

Metabolic Syndrome (MetS) is a clinical diagnosis where patients exhibit three out of the five risk factors: hypertriglyceridemia, low high-density lipoprotein (HDL) cholesterol, hyperglycemia, elevated blood pressure, or increased abdominal obesity. MetS arises due to dysregulated metabolic pathways that culminate with insulin resistance and put individuals at risk to develop various comorbidities with far-reaching medical consequences such as non-alcoholic fatty liver disease (NAFLD) and cardiovascular disease. As it stands, the exact pathogenesis of MetS as well as the involvement of the gastrointestinal tract in MetS is not fully understood. Our study aimed to evaluate intestinal health in human subjects with MetS.

METHODS

We examined MetS risk factors in individuals through body measurements and clinical and biochemical blood analysis. To evaluate intestinal health, gut inflammation was measured by fecal calprotectin, intestinal permeability through the lactulose-mannitol test, and utilized fecal metabolomics to examine alterations in the host-microbiota gut metabolism.

RESULTS

No signs of intestinal inflammation or increased intestinal permeability were observed in the MetS group compared to our control group. However, we found a significant increase in 417 lipid features of the gut lipidome in our MetS cohort. An identified fecal lipid, diacyl-glycerophosphocholine, showed a strong correlation with several MetS risk factors. Although our MetS cohort showed no signs of intestinal inflammation, they presented with increased levels of serum TNFα that also correlated with increasing triglyceride and fecal diacyl-glycerophosphocholine levels and decreasing HDL cholesterol levels.

CONCLUSION

Taken together, our main results show that MetS subjects showed major alterations in fecal lipid profiles suggesting alterations in the intestinal host-microbiota metabolism that may arise before concrete signs of gut inflammation or intestinal permeability become apparent. Lastly, we posit that fecal metabolomics could serve as a non-invasive, accurate screening method for both MetS and NAFLD.

Diagnostic Potential of Calprotectin for Spontaneous Bacterial Peritonitis in Patients Withliver Cirrhosis and Ascites

The development of spontaneous bacterial peritonitis (SBP) is a serious and life-threatening condition in patients with cirrhosis and ascites. The aim of this study was to determine the diagnostic potential of calprotectin in ascites, for SBP in patients with liver cirrhosis and ascites before and after antibiotic treatment and to compare the mean values of calprotectin in ascites in patients with and without SBP. This prospective-observational study was comprised of 70 patients with cirrhosis and ascites, divided into two groups, the SBP and the non-SBP group. Quantitative measurements of calprotectin in ascites was completed with the Quantum Blue Calprotectin Ascites test (LF-ASC25), using the Quantum Blue Reader. The average value of calprotectin in the SBP group was 1.5 ± 0.40 μg / mL, and in the non-SBP group it was lower (0.4 ± 0.30). The difference between the mean values was statistically significant with p <0.05. The mean value of calprotectin in ascites before therapy among the SBP group was 1.5 ± 0.4, and after antibiotic therapy, the value decreased significantly to 1.0 ± 0.6; the difference between the mean values was statistically significant with p <0.05. ROC analysis indicated that calprotectin contributed to the diagnosis of SBP with a 94.3% sensitivity rating (to correctly identify positives), and the specificity was 62.5%, which corresponded to the value of 0.275. Our research confirmed that ascitic calprotectin was a good predictor, and is significantly associated with the occurrence of SBP in patients with liver cirrhosis. By monitoring the value of calprotectin in ascites on the 7th day of antibiotic treatment, the effectiveness of antibiotic treatment in patients with SBP can be determined.

Deletion of intestinal SIRT1 exacerbated muscle wasting in cirrhotic mice by decreasing the intestinal concentration of short-chain fatty acids and inflammation

Systemic sirtuin 1 (SIRT1) activation alleviates muscle wasting and improves muscle function by downregulation of myotropic and proteolytic markers. In this study, we evaluated the effects of the intestinal Sirt1 deletion on the dysregulated gutmuscle axis in cirrhotic mice. Cirrhosis-related muscle wasting was induced by common bile duct ligated (BDL) in either wild-type (WT) or intestine-specific Sirt1-deleted (Sirt1IEC-KO) mice, including WT-BDL, WT-sham, Sirt1IEC-KO-BDL and Sirt1IEC-KO-sham mice. Compared with WT-BDL mice, Sirt1IEC-KO-BDL mice showed worsened low lean mass, exacerbated muscle wasting, increased expression of myotropic markers, increased muscular protein degradation, and decreased expression of myogenic markers through aggravation of intestinal inflammation (as evidenced by increased fecal calprotectin/lipocalin-2 levels, increased intestinal macrophage infiltration, and increased intestinal TNFα/IL-6 levels), decrease in abundance of short-chain fatty acid (SCFA)-producing bacteria, decrease in levels of intestinal SCFAs (with anti-inflammatory effects), and downregulation of SCFA receptor GPR43. In biliary cirrhotic mice, a decrease in the abundance of SCFA-producing bacteria and an increase in the levels of intestinal/muscular inflammatory markers are involved in the pathogenesis of dysregulated gut-muscle axis-related muscle wasting, and intestinal deletion of Sirt1 exacerbated these changes.

International consensus on methodological issues in standardization of fecal calprotectin measurement in inflammatory bowel diseases

BACKGROUND

Fecal calprotectin (FC) is a non-invasive marker of gut inflammation which is frequently used to guide therapeutic decisions in patients with inflammatory bowel diseases (IBD). Each step of FC measurement can influence the results, leading to misinterpretations and potentially impacting the management of IBD patients. To date, there is high heterogeneity between FC measurements and no current method is universally accepted as a standard.

AIMS

Our aim was to provide clear position statementsabout the pre-analytical and the analytical phases of FC measurement to homogenize FC levels and to minimize variability and risk of misinterpretation through aninternational consensus.

MATERIALS & METHODS

Fourteen physicians with expertise in the field of IBD and FC from 11 countries attended a virtual international consensus meeting on July 17th, 2020. A systematic literature was conducted and the literature evidence was shared and discussedamong the participants. Statements were formulated, discussed, and voted. Statements were considered approved if all participants agreed.

RESULTS

Nine statements were formulated and approved. Based on the available evidence, quantitative tests should be preferred for measuring FC. Furthermore, FC measurement, if possible, should always be performed with the same method and factors influencing FC levels should be taken into account when interpreting the results.

DISCUSSION

FC has an increasingly important role in the management of patients with IBD. However, large multicenter studies should be conducted to define the reproducibility and to confirm the diagnostic accuracy of the available FC tests.

CONCLUSION

FC concentrations guide clinicians' treatment decisions. Our statements have a relevant impact in daily practice and could be applied in clinical trials to standardize FC measurement.

The diagnostic accuracy of ascitic calprotectin for the early diagnosis of spontaneous bacterial peritonitis: systematic review and meta-analysis

Spontaneous bacterial peritonitis (SBP) is a common complication in patients with cirrhosis and has an incidence of up to 30% in hospitalized patients. Importantly, it may raise their mortality rate up to 30%. Hence, a delayed diagnosis is associated with poor prognosis. This systematic review aims to assess the diagnostic accuracy of ascitic fluid calprotectin for the early diagnosis of SBP in patients with ascites. This study was conducted in accordance with the PRISMA statement. A systematic literature search was conducted from inception to February 2020 in the following electronic bibliographic databases: MEDLINE, Scopus, The Cochrane Library and OpenGrey. Quality Assessment of Diagnostic Accuracy Studies tool was used to assess risk of bias. Ten studies were included in the qualitative and quantitative synthesis. Hierarchical summary receiver operating characteristic curves were plotted and the summary sensitivity of a positive ascitic fluid calprotectin assessment to detect SBP was 93% [95% confidence interval (CI) 90-95%] while the summary specificity was 89% (95% CI 80-95%), irrespectively of the method used. The positive likelihood ratio and negative likelihood ratio of the test were 8.7 (95% CI 4.4-17.1) and 0.08 (85% CI 0.06-0.12). All studies showed positive correlation between ascitic calprotectin and polymorphonuclear (PMN) leukocyte count. Ascitic calprotectin appears to be an excellent alternative to PMN leucocyte count of ≥250 cells/mm3 for the diagnosis of SBP with much faster time to diagnosis. Owing to its substantially high negative predictive value, the test can accurately exclude SBP avoiding unnecessary antibiotics in suspected patients.

A Practical Guide for Faecal Calprotectin Measurement: Myths and Realities

BACKGROUND AND AIMS

Faecal calprotectin [FC] is a valid and non-invasive marker of mucosal inflammation. It is widely used both in clinical trials and in daily clinical practice for patients with inflammatory bowel diseases, but currently no accepted standardization for FC testing is available. Our primary aim here was to provide a clinician's guide containing all the practical information on FC measurement in order to avoid any confounding factors, to minimize intra- and inter-individual variability in dosage, and to ensure a better and adequate interpretation of the results.

METHODS

We conducted a detailed search of the scientific literature in the PubMed/MEDLINE, EMBASE and Cochrane databases up to January 2020 to find all relevant and available articles on pre-analytical and analytical phases of FC measurement.

RESULTS

FC testing is a multi-step procedure consisting of a pre-analytical phase aimed to collect and process the stool sample and a subsequent analytical phase of FC measurement. Several factors can influence test results determining false positives or false negatives. Importantly, this faecal marker is mostly used for patient follow-up and as a predictor of treatment response. For this reason, any altered data may affect the physicians' decisions, negatively impacting on patient management.

CONCLUSIONS

This review provides for the first time practical advice to minimize dosage variability, although further dedicated studies are needed to compare commercially available tests and identify the best tools for the most precise and accurate FC measurement.

Faecal cytokine profiling as a marker of intestinal inflammation in acutely decompensated cirrhosis

BACKGROUND & AIMS

Gut dysbiosis and inflammation perpetuate loss of gut barrier integrity (GBI) and pathological bacterial translocation (BT) in cirrhosis, contributing to infection risk. Little is known about gut inflammation in cirrhosis and how this differs in acute decompensation (AD). We developed a novel approach to characterise intestinal immunopathology by quantifying faecal cytokines (FCs) and GBI markers.

METHODS

Faeces and plasma were obtained from patients with stable cirrhosis (SC; n = 16), AD (n = 47), and healthy controls (HCs; n = 31). A panel of 15 cytokines and GBI markers, including intestinal fatty-acid-binding protein-2 (FABP2), d-lactate, and faecal calprotectin (FCAL), were quantified by electrochemiluminescence/ELISA. Correlations between analytes and clinical metadata with univariate and multivariate analyses were performed.

RESULTS

Faecal (F) IL-1β, interferon gamma, tumour necrosis factor alpha, IL-21, IL-17A/F, and IL-22 were significantly elevated in AD vs. SC (q <0.01). F-IL-23 was significantly elevated in AD vs. HC (p = 0.0007). FABP2/d-lactate were significantly increased in faeces in AD vs. SC and AD vs. HC (p <0.0001) and in plasma (p = 0.0004; p = 0.011). F-FABP2 correlated most strongly with disease severity (Spearman's rho: Child-Pugh 0.466; p <0.0001; model for end-stage liver disease 0.488; p <0.0001). FCAL correlated with plasma IL-21, IL-1β, and IL-17F only and none of the faecal analytes. F-cytokines and F-GBI markers were more accurate than plasma in discriminating AD from SC.

CONCLUSIONS

FC profiling represents an innovative approach to investigating the localised intestinal cytokine micro-environment in cirrhosis. These data reveal that AD is associated with a highly inflamed and permeable gut barrier. FC profiles are very different from the classical innate-like features of systemic inflammation. There is non-specific upregulation of TH1/TH17 effector cytokines and those known to mediate intestinal barrier damage. This prevents mucosal healing in AD and further propagates BT and systemic inflammation.

LAY SUMMARY

The gut barrier is crucial in cirrhosis in preventing infection-causing bacteria that normally live in the gut from accessing the liver and other organs via the bloodstream. Herein, we characterised gut inflammation by measuring different markers in stool samples from patients at different stages of cirrhosis and comparing this to healthy people. These markers, when compared with equivalent markers usually measured in blood, were found to be very different in pattern and absolute levels, suggesting that there is significant gut inflammation in cirrhosis related to different immune system pathways to that seen outside of the gut. This provides new insights into gut-specific immune disturbances that predispose to complications of cirrhosis, and emphasises that a better understanding of the gut-liver axis is necessary to develop better targeted therapies.

Recurrence of spontaneous bacterial peritonitis in cirrhosis: novel predictors

BACKGROUND AND AIMS

Recurrence of spontaneous bacterial peritonitis (SBP) is still a matter of debate. We conducted this study to evaluate the probable factors that predict the recurrence of SBP in patients who recovered from the first episode of SBP and the long-term outcomes of SBP recurrence.

METHODS

One hundred twenty-four patients diagnosed with liver cirrhosis, SBP and did not receive secondary prophylaxis either with norfloxacin or other antibiotics were included in this prospective cohort pilot study. Clinical, biochemical and ascitic fluid analysis parameters were evaluated. Ascitic fluid interferon-γ-induced protein (IP-10), calprotectin, interleukin-6 and tumor necrosis factor-α were measured by ELISA.

RESULTS

Of these, 76 patients survived with an in-hospital mortality rate of 38.7%. The survivors were classified into two groups according to recurrence and nonrecurrence of SBP and survival time, clinical parameters and cause of death were investigated. Thirty-one participants had one or more attacks of SBP, with a recurrence rate of 40.8% within one-year follow-up. Before discharge, multivariate analysis showed that ascitic IP-10 (≥1220 pg/ml), ascitic calprotectin (≥550 ng/ml), serum albumin (≤2.5 g/dl), nonuse of prophylactic β-blockers and use of proton-pump inhibitors (PPIs) were the independent variables in predicting recurrent SBP. Sepsis-related organ failure was the most common etiology of mortality in the recurrent SBP group within 3 and 6 months.

CONCLUSION

Increased ascitic calprotectin and IP-10, hypoalbuminemia, nonuse of prophylactic β-blockers and use of PPI were independently associated with increased SBP recurrence rate. Sepsis-related organ failure was the most common etiology of mortality.

A novel serum index for accurate diagnosis of spontaneous bacterial peritonitis in cirrhotic patients without other infections

Background

The accurate non-invasive diagnosis of spontaneous bacterial peritonitis (SBP) in patients with decompensated liver cirrhosis has not been achieved yet. The aim of the study was to obtain an unmistakable diagnosis of SBP using a new simple serum bioscore, made by combined measurement of procalcitonin (PCT), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP), which we called the PEC index. This cross-sectional analytic study comprised 178 cirrhotic patients with ascites (60 patients with SBP and 118 patients with sterile ascites), after excluding non-SBP infection, during the period from March 2019 until September 2019. In all participants, serum levels of PCT, ESR, and CRP were measured, and PEC index was calculated [PEC index = PCT × (ESR + CRP)].

Results

Patients with SBP (n = 60) had significantly higher serum PEC index than those with sterile ascites (n = 118) (41.0/31.2–93.0 vs. 9.9/5.9–15.0, P < 0.001). PEC index distinguished culture positive cases significantly (P < 0.001). Using receiver operating characteristic (ROC) statistics, the sensitivity and specificity of PCT, at a cutoff value of 0.590 ng/mL, for SBP diagnosis, were 81.67% and 93.33%, respectively (area under the curve [AUC] = 0.879; 95% confidence interval [CI] 0.809–0.948). The sensitivity and specificity of ESR, at a cutoff value of 27.0 mm/hour, were 73.33% and 61.67%, respectively (AUC = 0.679; 95% CI 0.581–0.776). The sensitivity and specificity of CRP, at a cutoff value of 21.0 mg/L, were 93.33% and 51.67%, respectively (AUC = 0.736; 95% CI 0.639–0.833). While, the sensitivity and specificity of PEC index, at a cutoff value of 20, were highest (98.33% and 96.67%, respectively, AUC = 0.977; 95% CI 0.940–0.996).

Conclusion

Serum PEC index makes an accurate noninvasive diagnosis of SBP, after excluding other infections.

Ascitic calprotectin as a useful marker in the diagnosis of spontaneous bacterial peritonitis in adults

Background

Ascitic fluid polymorphonuclear leucocyte count (PMN) is known to be the gold standard for spontaneous bacterial peritonitis (SBP) diagnosis. The aim of this work was to assess ascitic calprotectin for SBP diagnosis. Serum C-reactive protein (CRP), high sensitivity C-reactive protein (hsCRP), nitrous oxide, ascitic PMN, ascitic leucocyte esterase and ascitic calprotectin were measured.

Results

The average age of our patients was 55.25 ± 7.89 years, mostly males (n = 51, 63.8%), anti-HCV antibodies were positive in (n = 61, 76.3%). Sixty-four patients (80%) were Child-Pugh C and their average MELD was 24.29 ± 8.06. Patients with SBP had statistically significant higher median MELD score (26.5 vs. 19) and higher average Child-Pugh score (12.18 ± 1.74 vs. 10.5 ± 1.97). Forty patients had SBP and 40 patients were without SBP. Both the serum and ascitic nitrous oxide did not differ statistically between patients with and without SBP. In contrast, patients with SBP had higher median serum CRP (49 vs. 12 mg/dL), hsCRP (58,000 vs. 23,750 ng/dL) and ascitic calprotectin (7.57 vs. 1.1 ng/mL). The ascitic leucocyte esterase test was positive in 95% of SBP patients in contrast to 2.5% patients without SBP. Ascitic calprotectin >2 ng/mL had 90% sensitivity, 92.5% specificity, 92.3% positive predictive value and 90.2% negative predictive value. MELD, CRP, hsCRP and ascitic calprotectin are independent predictors of SBP.

Conclusion

Ascitic calprotectin is a useful marker for SBP diagnosis.

Mansoura simple scoring system for prediction of spontaneous bacterial peritonitis: lesson learnt

BACKGROUND AND OBJECTIVE

Spontaneous bacterial peritonitis (SBP) is a common bacterial infection with life-threatening sequelae in cirrhotic ascites. The purpose of this retrospective cohort study was to recognize the predictors of SBP to build up a noninvasive system to exclude or establish an episode of SBP.

PATIENTS AND METHODS

Of 1194 consecutive patients with cirrhotic ascites, only 966 patients were enrolled in this study. SBP was diagnosed once polymorphonuclear count was at least 250 cells/mm and/or there was a positive ascitic fluid culture result. Biochemical and clinical parameters were evaluated as predictors of SBP. A scoring system was established in the training group of 682 and validated in a second group of 284 participants.

RESULTS

The incidence of SBP was 12.3 and 12% in the training and validation groups, respectively. Age of at least 55 years, mean platelet volume (MPV) of at least 8.5 fl, neutrophil-to-lymphocyte ratio (NLR) of at least 2.5, and C-reactive protein (CRP) of at least 40 mg/l were identified as independent predictors of SBP. A scoring system including these four variables (age, MPV, and NLR with 1 point each, whereas CRP with 2 points) achieves a specificity of 98.2% with a positive predictive value for the diagnosis of SBP of 88.1% (score≥4). At a threshold of 1 point, the negative predictive value is 97.5% with a sensitivity of 92.9%. SBP is not associated with a high Model for End-stage Liver Disease score (P=0.135).

CONCLUSION

The combination of age, MPV, NLR, and CRP in a simple scoring system, Mansoura simple scoring system, supports quick and accurate exclusion or diagnosis of SBP.

Clinical utility of fecal calprotectin: potential applications beyond inflammatory bowel disease for the primary care physician

Fecal calprotectin (FC) is an inflammatory marker released mainly from gastrointestinal granulocytes measured in stool samples. FC is noninvasive, economical, simple, and acceptable for patients. Levels of FC have proven reliable for intestinal inflammation, with good clinical sensitivity, and are useful in screening and monitoring inflammatory bowel disease (IBD), as well as in the differential diagnosis between IBD and irritable bowel syndrome (IBS). Given its advantages, FC represents an attractive biomarker that could be utilized in various gastrointestinal (GI) diseases apart from IBD, and is currently being studied extensively by many research groups with significant amounts of data emerging. In this current review we aim to provide an outline of the utility of FC in distinguishing between IBS and IBD, as well as an up-to-date summary of the available clinical experience concerning FC in various common conditions of the GI tract commonly encountered by gastroenterology practitioners, such as IBS, microscopic colitis, acute gastroenteritis, Clostridium difficile infection, colorectal cancer, diverticular disease, coeliac disease, and other GI conditions.

Hepatocellular Carcinoma Is Associated With Gut Microbiota Profile and Inflammation in Nonalcoholic Fatty Liver Disease

The gut-liver axis plays a pivotal role in the pathogenesis of nonalcoholic fatty liver disease (NAFLD), which is the third leading cause of hepatocellular carcinoma (HCC) worldwide. However, the link between gut microbiota and hepatocarcinogenesis remains to be clarified. The aim of this study was to explore what features of the gut microbiota are associated with HCC in patients with cirrhosis and NAFLD. A consecutive series of patients with NAFLD-related cirrhosis and HCC (group 1, 21 patients), NAFLD-related cirrhosis without HCC (group 2, 20 patients), and healthy controls (group 3, 20 patients) was studied for gut microbiota profile, intestinal permeability, inflammatory status, and circulating mononuclear cells. We finally constructed a model depicting the most relevant correlations among these features, possibly involved in hepatocarcinogenesis. Patients with HCC showed increased levels of fecal calprotectin, while intestinal permeability was similar to patients with cirrhosis but without HCC. Plasma levels of interleukin 8 (IL8), IL13, chemokine (C-C motif) ligand (CCL) 3, CCL4, and CCL5 were higher in the HCC group and associated with an activated status of circulating monocytes. The fecal microbiota of the whole group of patients with cirrhosis showed higher abundance of Enterobacteriaceae and Streptococcus and a reduction in Akkermansia. Bacteroides and Ruminococcaceae were increased in the HCC group, while Bifidobacterium was reduced. Akkermansia and Bifidobacterium were inversely correlated with calprotectin concentration, which in turn was associated with humoral and cellular inflammatory markers. A similar behavior was also observed for Bacteroides. Conclusion: Our results suggest that in patients with cirrhosis and NAFLD the gut microbiota profile and systemic inflammation are significantly correlated and can concur in the process of hepatocarcinogenesis.

Olfactory Function is Affected in Patients with Cirrhosis Depending on the Severity of Hepatic Encephalopathy

INTRODUCTION AND AIM

Olfactory functions are altered to a variable degree by chronic liver disease. Few studies including only small populations of patients emphasized the possibility of hepatic encephalopathy (HE) influencing olfactory nervous tasks. So far, no study has explicitly focused on olfactory function depending on the severity of HE as assessed by objective diagnostic procedures. Thus we performed a study using the "Sniffin' Sticks" test system, critical flicker-fusion frequency (CFF) and clinical West Haven criteria.

MATERIAL AND METHODS

54 cirrhotic patients with liver cirrhosis were included. Furthermore, 43 adult volunteers participating as a non-cirrhotic control group. Olfactory testing was performed using the "Sniffin' Stick" test battery (Burghart Medizintechnik, Wedel, Germany) which renders a widely-used tool both in clinical and research settings for the assessment of olfactory threshold, odor identification and discrimination. Several complications of cirrhosis were diagnosed by reference methods. Statistical analysis of cirrhosis-associated complications and their relation to olfactory function was performed. Assessment of HE and classification of different stages were performed according to clinical criteria (West- Haven criteria) and according to CFF, which was determined using a portable analyzer.

RESULTS

Olfactory function was significantly reduced in cirrhotic patients (in 61.1%) compared to controls (p &lt; 0.001). Among cirrhotics patients, the prevalence of olfactory deficits (hyposmia, anosmia) increased with the severity of HE as assessed by CFF and clinical criteria (p = 0.008 and p = 0.097, respectively). No correlation was observed between olfactory deficits and severity of liver disease as assessed by Child-Pugh-Score, etiology of cirrhosis and complications of cirrhosis such as ascites and portal venous hypertension.

CONCLUSIONS

Olfactory testing serves as a screening tool for HE and may facilitate grading of HE-severity.

Bacterial translocation in patients with liver cirrhosis: physiology, clinical consequences, and practical implications

The gut liver axis is an operative unit that works to protect the human body against potentially harmful substances and microorganisms, maintaining the homeostasis of the immune system. Liver cirrhosis profoundly alters this complex system. The intestine becomes more permeable allowing the translocation of bacteria, bacterial products and fragments into the portal circulation, triggering an abnormal local and systemic inflammatory response and a condition of perpetual immunologic alarm. This immune-inflammatory disorder related to dysbiosis is involved in the development of liver damage and liver cirrhosis complications and increases intestinal permeability in a vicious circle. Areas covered: The most relevant studies on bacterial translocation, the mechanism of intestinal barrier dysfunction and its consequences in patients with liver cirrhosis have been revised through a PubMed search. Data have been discussed with particular regard to their significance in clinical practice. Expert commentary: The assessment of bacterial translocation and intestinal permeability is not currently used in clinical practice but may be useful to stratify patients' prognosis.

Homocysteine: a new diagnostic marker in spontaneous bacterial peritonitis

BACKGROUND AND AIMS

The diagnosis of spontaneous bacterial peritonitis (SBP) depends primarily on a polymorphonuclear leukocyte cell count more than 250/mm. This method is invasive, and not diagnostic in all variants of SBP; we aimed to assess serum homocysteine as a precise indicative marker for the diagnosis of all variants of SBP.

PATIENTS AND METHODS

A total 323 consecutive ascitic patients were registered in this prospective work. Serum and ascitic fluid of homocysteine were evaluated utilizing an enzyme-linked immunosorbent assay.

RESULTS

Participants were classified into a non-SBP group, including 262 participants and 61 patients with SBP. Serum and ascitic homocysteine were considerably elevated in the SBP group than in the non-SBP group (17.94±7.57 vs. 11.75±5.68 μmol/l; P<0.001 and 14.70±5.45 vs. 9.75±4.55 μmol/l; P<0.001). At a cutoff value of 17.79 μmol/l, serum homocysteine had 89.3% specificity and 95.1% sensitivity for distinguishing SBP (area under the curve: 0.932) and, at a cutoff value of 16.1 μmol/l, ascitic homocysteine had 84.4% specificity and 92.7% sensitivity for distinguishing SBP (area under the curve: 0.901). Both were positively correlated with the polymorphonuclear count, C-reactive protein, Child-Pugh score, and Model For End-Stage Liver Disease score as well as negatively correlated with the protein content in the ascitic fluid and estimated glomerular filtration rate. After SBP therapy, there was a marked reduction in serum and ascitic homocysteine levels.

CONCLUSION

This study demonstrates that serum and ascitic homocysteine are considerably higher in SBP participants versus non-SBP patients. Serum homocysteine may provide a reliable and noninvasive diagnostic marker for all variants of SBP.

Within-Stool and Within-Day Sample Variability of Fecal Calprotectin in Patients With Inflammatory Bowel Disease: A Prospective Observational Study

BACKGROUND AND GOALS

The use of fecal calprotectin (FC) as a stool biomarker for differentiating inflammatory bowel disease (IBD) from IBS has been well validated, and there is a strong correlation between FC and the presence of endoscopic inflammatory lesions. However, recent studies have demonstrated intraindividual sample variability in patients with IBD, possibly limiting the reliability of using a single sample for monitoring disease activity. Our aim was to assess the within-stool and within-day sample variability of FC concentrations in patients with IBD.

STUDY

We examined a cross-sectional cohort of 50 adult IBD patients. Eligible patients were instructed to collect 3 samples from different parts of the stool from their first bowel movement of the day and 3 samples from each of up to 2 additional bowel movements within 24 hours. FC concentrations were measured by a rapid, quantitative point-of-care test using lateral flow technology (Quantum Blue). Descriptive statistics were used to assess FC variability within a single bowel movement and between different movements at different FC positivity cutoffs.

RESULTS

Within a single bowel movement, there was clinically significant sample variability ranging from 8% to 23% depending on the time of the day or on the FC positivity cutoff value. Between bowel movements, there was clinically significant sample variability ranging from 13% to 26% depending on the FC positivity cutoff.

CONCLUSIONS

Considering a single FC sample, the first sample of the day with an FC positivity cutoff of 250 μg/g provided the most reliable indication of disease activity.

Bacterial translocation markers in liver cirrhosis

Bacterial translocation (BT) is an important mechanism in the development of infection in liver cirrhosis. The migration and colonization of bacteria and/or bacterial products from the bowel to mesenteric lymph nodes is a controlled process in healthy persons. Increased intestinal permeability, bacterial overgrowth and defect of gut-associated lymphatic tissue promote impaired BT in cirrhotics. We reviewed the reports on markers used for the evaluation of BT published between 1987 and 2016. We focused on the clinical consequences of BT in cirrhosis, as indicated by the values of the BT markers. Patients with cirrhosis are reported to have elevated levels of surrogate markers associated with BT compared with controls. The most widely used BT parameters are C-reactive protein, procalcitonin, bacterial DNA, endotoxin or lipopolysaccharide, lipopolysaccharide binding protein, calprotectin, and bactericidal/permeability increasing protein. High levels of these factors in serum and/or ascitic fluid in humans may be associated with advanced liver disease, hemodynamic instability, high levels of proinflammatory cytokines, susceptibility to the development of severe or recurrent infections, acute-on-chronic liver failure, hepatic encephalopathy, hepatorenal syndrome and poor prognosis during follow up. In conclusion, high levels of BT markers are associated with a high inflammatory response, increased complications of liver cirrhosis and occasionally high fatality rates.

Bacterial translocation in critical illness

Bacterial translocation involves the passage of intestinal bacteria to extraintestinal sites and has been shown to increase morbidity and mortality in critical illness. This review outlines the pathophysiology of bacterial translocation, host defence mechanisms, and reviews the evidence for the clinical management of critically ill patients in order to minimise the negative outcomes associated with bacterial translocation.

Ascitic Calprotectin is a Novel and Accurate Marker for Spontaneous Bacterial Peritonitis

BACKGROUND

Spontaneous bacterial peritonitis (SBP) is a known complication of advanced cirrhosis and presents a high mortality rate. A polymorphonuclear (PMN) cell count >250/μl in the ascitic fluid is the current gold standard for diagnosing SBP.

AIM

We evaluated the accuracy of a point-of-care test (POCT) for ascitic calprotectin in diagnosing patients with SBP.

METHODS

Eighty-eight patients admitted with decompensation of liver cirrhosis were studied including 41 patients (46.6%) with SBP. Ascitic calprotectin was measured using a quantitative POCT developed by Bühlmann^® .

RESULTS

Calprotectin levels correlated with PMN cell count and other inflammatory markers and were significantly higher in patients with SBP. An optimal cutoff of calprotectin above 1.57 μg/ml presented high sensitivity (87.8%), specificity (97.9%), and positive (97.3%) and negative (90.2%) predictive values for diagnosing SBP. Using calprotectin selectively in patients with a serum albumin-ascites gradient above 11 g/l further increased the sensitivity and negative predictive values of the test.

CONCLUSION

Ascitic calprotectin appears to be a reliable method for diagnosing SBP in patients with liver cirrhosis. It may present an alternative to other conventional diagnostic methods.

Gut epithelial barrier dysfunction in human immunodeficiency virus-hepatitis C virus coinfected patients: Influence on innate and acquired immunity

Even in cases where viral replication has been controlled by antiretroviral therapy for long periods of time, human immunodeficiency virus (HIV)-infected patients have several non-acquired immunodeficiency syndrome (AIDS) related co-morbidities, including liver disease, cardiovascular disease and neurocognitive decline, which have a clear impact on survival. It has been considered that persistent innate and acquired immune activation contributes to the pathogenesis of these non-AIDS related diseases. Immune activation has been related with several conditions, remarkably with the bacterial translocation related with the intestinal barrier damage by the HIV or by hepatitis C virus (HCV)-related liver cirrhosis. Consequently, increased morbidity and mortality must be expected in HIV-HCV coinfected patients. Disrupted gut barrier lead to an increased passage of microbial products and to an activation of the mucosal immune system and secretion of inflammatory mediators, which in turn might increase barrier dysfunction. In the present review, the intestinal barrier structure, measures of intestinal barrier dysfunction and the modifications of them in HIV monoinfection and in HIV-HCV coinfection will be considered. Both pathogenesis and the consequences for the progression of liver disease secondary to gut microbial fragment leakage and immune activation will be assessed.

Markers of bacterial translocation in end-stage liver disease

Bacterial translocation (BT) refers to the passage of viable bacteria or bacterial products from the intestinal lumen, through the intestinal epithelium, into the systemic circulation and extraintestinal locations. The three principal mechanisms that are thought to be involved in BT include bacterial overgrowth, disruption of the gut mucosal barrier and an impaired host defence. BT is commonly observed in liver cirrhosis and has been shown to play an important role in the pathogenesis of the complications of end stage liver disease, including infections as well as hepatic encephalopathy and hepatorenal syndrome. Due to the importance of BT in the natural history of cirrhosis, there is intense interest for the discovery of biomarkers of BT. To date, several such candidates have been proposed, which include bacterial DNA, soluble CD14, lipopolysaccharides endotoxin, lipopolysaccharide-binding protein, calprotectin and procalcitonin. Studies on the association of these markers with BT have demonstrated not only promising data but, oftentimes, contradictory results. As a consequence, currently, there is no optimal marker that may be used in clinical practice as a surrogate for the presence of BT.

Fecal calprotectin use in inflammatory bowel disease and beyond: A mini-review

Given the number of inflammatory disorders affecting the gastrointestinal tract directly and indirectly, coupled with the considerable overlap with functional disorders, it is evident that more useful noninvasive diagnostic tests are required to aid with diagnosis. If these tests can also have some utility for individual patient follow-up in terms of disease activity and response to treatment, as well as providing forewarning of disease relapse, it would be extremely useful information for the clinician. One recently described test that may fulfill several of these attributes is based on leakage of a mononuclear cell cytoplasmic protein, calprotectin, along the intestinal tract, which can then be quantified in feces. This has been used to distinguish patients exhibiting symptoms of irritable bowel syndrome from patients with inflammatory bowel disease, with a measure of success greater than with currently used techniques. The present article summarizes the experience with this test used in inflammatory bowel disease, as well as a variety of gastrointestinal disorders.

Bacterial infections in cirrhosis: a position statement based on the EASL Special Conference 2013

Bacterial infections are very common and represent one of the most important reasons of progression of liver failure, development of liver-related complications, and mortality in patients with cirrhosis. In fact, bacterial infections may be a triggering factor for the occurrence of gastrointestinal bleeding, hypervolemic hyponatremia, hepatic encephalopathy, kidney failure, and development of acute-on-chronic liver failure. Moreover, infections are a very common cause of repeated hospitalizations, impaired health-related quality of life, and increased healthcare costs in cirrhosis. Bacterial infections develop as a consequence of immune dysfunction that occurs progressively during the course of cirrhosis. In a significant proportion of patients, infections are caused by gram-negative bacteria from intestinal origin, yet gram-positive bacteria are a frequent cause of infection, particularly in hospitalized patients. In recent years, infections caused by multidrug-resistant bacteria are becoming an important clinical problem in many countries. The reduction of the negative clinical impact of infections in patients with cirrhosis may be achieved by a combination of prophylactic measures, such as administration of antibiotics, to reduce the occurrence of infections in high-risk groups together with early identification and management of infection once it has developed. Investigation on the mechanisms of altered gut microflora, translocation of bacteria, and immune dysfunction may help develop more effective and safe methods of prevention compared to those that are currently available. Moreover, research on biomarkers of early infection may be useful in early diagnosis and treatment of infections. The current manuscript reports an in-depth review and a position statement on bacterial infections in cirrhosis.

Faecal calprotectin as a novel biomarker for differentiating between inflammatory bowel disease and irritable bowel syndrome

The present study aimed to investigate faecal calprotectin as a diagnostic marker to differentiate between patients with inflammatory bowel disease (IBD) and those with irritable bowel syndrome (IBS). A total of 20 healthy control subjects, 26 patients with IBS and 58 patients with IBD, including 22 with ulcerative colitis (UC) and 36 with Crohn's disease (CD), were recruited for the present study. Calprotectin was analysed in stool samples, and C-reactive protein (CRP) and the erythrocyte sedimentation rate (ESR) were assessed in blood samples. CRP and calprotectin levels, and the ESR were observed to be significantly higher in patients with CD and UC compared with those of the healthy control subjects (P<0.0001). Furthermore, in patients with IBD and IBS, significant increases in faecal calprotectin and CRP levels were observed (694.8±685.0 µg/g in IBD vs. 85.8±136.1 µg/g in IBS and 0.851±1.200 mg/dl in IBD vs. 0.16±0.23 mg/dl in IBS, respectively; P<0.0001). Area under the receiver operating characteristic curve analysis revealed that, in patients with IBD, the levels of faecal calprotectin [0.931±0.029; 95% confidence interval (CI), 0.874‑0.987] were significantly higher than that of CRP (0.865±0.041; 95% CI, 0.785‑0.946) and the ESR (0.869±0.042; 95% CI, 0.786‑0.952). These findings indicate that faecal calprotectin may represent a novel biomarker for diagnosing IBD and may be effective in distinguishing between IBD and IBS.

Intestinal epithelial barrier function in liver cirrhosis: an extensive review of the literature

Recent evidence suggests that translocation of bacteria and bacterial products, such as endotoxin from the intestinal lumen into the systemic circulation is a contributing factor in the pathogenesis of chronic liver diseases and the development of complications in cirrhosis. In addition to alterations in the intestinal microbiota and immune system, dysfunction of the intestinal epithelial barrier may be an important factor facilitating bacterial translocation. This review aims to provide an overview of the current evidence of intestinal epithelial barrier dysfunction in human chronic liver diseases and cirrhosis, and to discuss possible contributing factors and mechanisms. Data suggest the presence of intestinal epithelial barrier dysfunction in patients with chronic liver diseases, but are more convincing in patients with cirrhosis, especially in those with complications. The barrier dysfunction can result from both direct and indirect effects of aetiological factors, such as alcohol and obesity, which can cause chronic liver diseases and ultimately cirrhosis. On the other hand characteristics of cirrhosis itself, including portal hypertension, alterations in the intestinal microbiota, inflammation and oxidative stress can affect barrier function of both small and large intestine and may contribute to the development of complications. In conclusion, there are indications for intestinal epithelial barrier dysfunction in patients with chronic liver diseases and especially in patients with cirrhosis, which can be caused by various factors affecting both the small and large intestine.

Role of diabetes mellitus on hepatic encephalopathy

Hepatic encephalopathy is the main cognitive dysfunction in cirrhotic patients associated with impaired prognosis. Hyperammonemia plus inflammatory response do play a crucial role on hepatic encephalopathy. However, in some patients HE appeared without hyperammonemia and patients with increased levels of ammonia could not show cognitive dysfunction. This has led to investigate other factors that could act in a synergistic way. Diabetes mellitus and insulin resistance are characterized by releasing and enhancing these pro-inflammatory cytokines and, additionally, has been related to hepatic encephalopathy. Indeed, patients with diabetes showed raised risk of over hepatic encephalopathy in comparison with non-cirrhotics. Type 2 diabetes mellitus could impair hepatic encephalopathy by different mechanisms that include: a) increasing glutaminase activity; b) impairing gut motility and promoting constipation, intestinal bacterial overgrowth and bacterial translocation. Despite of insufficient clarity about the practicability of anti-diabetic therapy and the most efficacious therapy, we would have to pay a special attention to the management of type 2 diabetes mellitus and insulin resistance in cirrhotic patients.

Metformin inhibits glutaminase activity and protects against hepatic encephalopathy

AIM

To investigate the influence of metformin use on liver dysfunction and hepatic encephalopathy in a retrospective cohort of diabetic cirrhotic patients. To analyze the impact of metformin on glutaminase activity and ammonia production in vitro.

METHODS

Eighty-two cirrhotic patients with type 2 diabetes were included. Forty-one patients were classified as insulin sensitizers experienced (metformin) and 41 as controls (cirrhotic patients with type 2 diabetes mellitus without metformin treatment). Baseline analysis included: insulin, glucose, glucagon, leptin, adiponectin, TNFr2, AST, ALT. HOMA-IR was calculated. Baseline HE risk was calculated according to minimal hepatic encephalopathy, oral glutamine challenge and mutations in glutaminase gene. We performed an experimental study in vitro including an enzymatic activity assay where glutaminase inhibition was measured according to different metformin concentrations. In Caco2 cells, glutaminase activity inhibition was evaluated by ammonia production at 24, 48 and 72 hours after metformina treatment.

RESULTS

Hepatic encephalopathy was diagnosed during follow-up in 23.2% (19/82): 4.9% (2/41) in patients receiving metformin and 41.5% (17/41) in patients without metformin treatment (logRank 9.81; p=0.002). In multivariate analysis, metformin use [H.R.11.4 (95% CI: 1.2-108.8); p=0.034], age at diagnosis [H.R.1.12 (95% CI: 1.04-1.2); p=0.002], female sex [H.R.10.4 (95% CI: 1.5-71.6); p=0.017] and HE risk [H.R.21.3 (95% CI: 2.8-163.4); p=0.003] were found independently associated with hepatic encephalopathy. In the enzymatic assay, glutaminase activity inhibition reached 68% with metformin 100 mM. In Caco2 cells, metformin (20 mM) decreased glutaminase activity up to 24% at 72 hours post-treatment (p<0.05).

CONCLUSIONS

Metformin was found independently related to overt hepatic encephalopathy in patients with type 2 diabetes mellitus and high risk of hepatic encephalopathy. Metformin inhibits glutaminase activity in vitro. Therefore, metformin use seems to be protective against hepatic encephalopathy in diabetic cirrhotic patients.