Intestinal permeability correlates with disease activity and DNA methylation changes in lupus patients.

OBJECTIVE: Systemic lupus erythematosus (SLE or lupus) is a chronic autoimmune disease that can involve various organ systems. Several studies have suggested that increased intestinal permeability may play a role in the pathogenesis of lupus. The aim of this study was to elucidate the relationship between intestinal permeability, disease activity, and epigenetic changes in lupus patients. METHODS: A total of 25 female lupus patients were included in this study. Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) scores were used as indicator of disease activity. Plasma zonulin levels were measured, using an ELISA, as a marker of intestinal permeability. Genome-wide DNA methylation patterns were assessed in neutrophils for 19 of the lupus patients using the Infinium MethylationEPIC array. Linear regression and Pearson's correlation were used to evaluate the correlation between zonulin concentrations and SLEDAI scores. The relationship between DNA methylation levels and zonulin concentrations was assessed using beta regression, linear regression, and Pearson's correlation, adjusting for age and race. RESULTS: Intestinal permeability positively correlated with disease activity in lupus patients (p-value = 7.60 × 10-3, r = 0.53). DNA methylation levels in 926 CpG sites significantly correlated with intestinal permeability. The highest correlation was identified in LRIG1 (cg14159396, FDR-adjusted p-value = 1.35 × 10-12, adjusted r2 = 0.92), which plays a role in intestinal homeostasis. Gene Ontologies related to cell-cell adhesion were enriched among the genes that were hypomethylated with increased intestinal permeability in lupus. CONCLUSION: Our data suggest a correlation between increased intestinal permeability and disease activity in lupus patients. Further, increased intestinal permeability might be associated with epigenetic changes that could play a role in the pathogenesis of lupus.

Probiotics Supplements Improve the Sarcopenia-Related Quality of Life in Older Adults with Age-Related Muscle Decline.

A pathological increase in intestinal leak is implicated in age-associated muscle loss, termed sarcopenia, and reduced sarcopenia-related quality-of-life (SarQoL). However, the potential therapies remain elusive. We investigated the effects of probiotic supplementation on sarcopenia and SarQoL in geriatric older adults. We randomized sarcopenic men into placebo (age = 71.4 ± 3.9 years, n = 63) and probiotic (age = 73 ± 4.1 years, n = 60) groups for 16 weeks. The probiotic used was one capsule daily of Vivomix 112 billion for 16 weeks. We measured sarcopenia parameters of handgrip strength (HGS) and skeletal mass index (SMI), plasma zonulin (marker of the intestinal leak), and SarQoL using a targeted questionnaire. Probiotics improved the SarQoL scores for locomotion, functionality, and activities of daily living and prevented a decline in cumulative SarQoL observed in the placebo group (all p < 0.05). Probiotic supplementation also reduced plasma zonulin and marker of systemic bacterial load. These changes were accompanied by an increase in HGS and maintenance of gait speed in the probiotic group compared to the placebo group. Correlation analysis revealed significant associations of cumulative SarQoL scores with plasma zonulin and HGS in the probiotic group. Collectively, probiotics improved SarQoL and HGS by repairing pathological intestinal leak. Future studies may further dissect the relation between intestinal leak and SarQoL in older adults taking probiotics.

The Association of Intestinal Leak with Sarcopenia and Physical Disability in Patients with Various Stages of Chronic Kidney Disease.

Sarcopenia is related to disease severity in chronic kidney disease (CKD) patients; however, its pathophysiology remains poorly known. We investigated the associations of biomarkers of intestinal leak with sarcopenia in various stages of CKD. We recruited 61-76-year-old male controls and patients with various stages of CKD (n = 36-57/group) for measuring plasma lipopolysaccharide-binding protein (LBP) and zonulin (markers of intestinal leak), handgrip strength (HGS), skeletal mass index (SMI), and gait speed (markers of sarcopenia), and short physical performance battery (SPPB; marker of physical capacity). CKD stages 4 and 5 were associated with lower HGS, SMI, gait speed, and cumulative SPPB scores and a higher sarcopenia prevalence than controls and patients with CKD stages 1 and 2 (all p < 0.05). CKD patients (stages 1 and 2) had elevated plasma zonulin and LBP when compared with CKD stages 4 and 5. Plasma zonulin and LBP exhibited significant correlations with renal function, HGS, gait speed, SPPB scores, and oxidative stress markers in CKD stages 4 and 5 (all p < 0.05). However, similar relations were not found in early CKD. Collectively, intestinal leak may be contributing to sarcopenia and physical disability in the advanced stages of CKD.

Ameliorative Effects of Larazotide Acetate on Intestinal Permeability and Bacterial Translocation in Acute Pancreatitis Model in Rats.

BACKGROUND: Intestinal barrier dysfunction in acute pancreatitis (AP) may progress to systemic inflammatory response syndrome (SIRS) and multi-organ failures by causing bacterial translocation. Larazotide acetate (LA) is a molecule that acts as a tight junction (TJ) regulator by blocking zonulin (Zo) receptors in the intestine. AIMS: In our study, we aimed to investigate the effects of LA on intestinal barrier dysfunction and bacterial translocation in the AP model in rats. METHODS: Thirty-two male Sprague-Dawley rats were divided into 4 groups; control, larazotide (LAR), AP, and AP + LAR. The AP model was created by administering 250 mg/100 g bm L-Arginine intraperitoneally 2 times with an hour interval. AP + LAR group received prophylactic 0.01 mg/mL LA orally for 7 days before the first dose of L-Arginine. For intestinal permeability analysis, fluorescein isothiocyanate-dextran (FITC-Dextran) was applied to rats by gavage. The positivity of any of the liver, small intestine mesentery, and spleen cultures were defined as bacterial translocation. Histopathologically damage and zonulin immunoreactivity in the intestine were investigated. RESULTS: Compared to the control group, the intestinal damage scores, anti-Zo-1 immunoreactivity H-Score, serum FITC-Dextran levels and bacterial translocation frequency (100% versus 0%) in the AP group were significantly higher (all p < 0.01). Intestinal damage scores, anti-Zo-1 immunoreactivity H-score, serum FITC-Dextran levels, and bacterial translocation frequency (50% versus 100%) were significantly lower in the AP + LAR group compared to the AP group (all p < 0.01). CONCLUSIONS: Our findings show that LA reduces the increased intestinal permeability and intestinal damage by its effect on Zo in the AP model in rats, and decreases the frequency of bacterial translocation as a result of these positive effects.

A leaky gut contributes to reduced sarcopenia-related quality of life (SarQoL) in geriatric older adults.

PURPOSE: The sarcopenia quality-of-life (SarQoL) questionnaire is designed to evaluate the quality of life of sarcopenic patients. A pathological increase in intestinal permeability leads to several systemic diseases, but its contribution to SarQoL is unknown. METHODS: We recruited controls (n = 84, age = 74.6 ± 4.9 years) and sarcopenic (n = 55, age = 76.1 ± 4.2 years) men for validating and adapting a Pashto version of SarQoL. We measured the scores for seven domains of SarQoL, body composition, and handgrip strength (HGS). We also measured plasma zonulin as a marker of increased intestinal permeability. RESULTS: The Pashto SarQoL exhibited adequate discriminative ability, construct validity, internal consistency, and test-retest reliability, without exhibiting the floor and ceiling effect. Sarcopenic patients had higher plasma zonulin and lower scores on SarQoL domains for physical and mental health, locomotion, body composition, functionality, activities of daily living, leisure, and fear, and cumulative SarQoL scores than controls. Plasma zonulin exhibited significant coefficients of determination with Pashto SarQoL domains for locomotion (r2 = 0.217), functionality (r2 = 0.101), activities of daily living (r2 = 0.302), and cumulative SarQoL scores (r2 = 0.168). We also found high efficacies of zonulin in diagnosing low scores for functionality (AUC = 0.785, 95% C.I = 0.708-0.863), activities of daily living (AUC = 0.785, 95% C.I = 0.708-0.863), and cumulative SarQoL scores (AUC = 0.821, 95% C.I = 0.751-0.891). CONCLUSION: Altogether, SarQoL appears reliable in measuring the quality of life in sarcopenic patients. A leaky gut has a potential contribution to reduced SarQoL in sarcopenia.

Gut-related molecules as potential biomarkers in patients with decompensated cirrhosis.

INTRODUCTION AND OBJECTIVES: Microbial translocation contributes to cirrhosis progression and complications. This study aims to investigate whether molecules related to intestinal permeability or microbial translocation can serve as prognostic biomarkers in patients with decompensated cirrhosis. MATERIALS AND METHODS: We prospectively evaluated hospitalized patients with decompensated cirrhosis for liver function, complications during hospitalization, in-hospital mortality, composite outcomes of in-hospital mortality and complications, 12-month mortality, and survival rates. Blood samples were collected upon admission, and 1,3 beta-d-glucan, zonulin, calprotectin, and lipopolysaccharide-binding protein were measured using commercial kits. RESULTS: Ninety-one patients with decompensated cirrhosis were enrolled. The mean age was 58 ± 12 years; 57% were male. The three main cirrhosis etiologies were hepatitis C (35%), alcohol (25%), and non-alcoholic steatohepatitis (17%). In terms of liver function, 52% were Child C, and 68% had model for end-stage liver disease ≥15. The in-hospital and one-year mortality rates were 31% and 57%, respectively. Child-Pugh, 1,3 beta-glucan, and model for end-stage liver disease were positively correlated; zonulin was associated with complications during hospitalization (acute kidney injury) and composite outcomes, and calprotectin was associated with all outcomes except 12-month mortality. CONCLUSIONS: Serum calprotectin and zonulin levels emerge as noninvasive prognostic biomarkers for potentially unfavorable outcomes in patients with decompensated cirrhosis.

Predictors of treatment failure of non-steroidal anti-inflammatory drugs in patients with axial spondyloarthritis with focus on haptoglobin, haptoglobin polymorphism and zonulin.

According to the Assessment of SpondyloArthritis International Society-European Alliance of Associations for Rheumatology (ASAS-EULAR) recommendations for the management of axial spondyloarthritis (axSpA), patients should undergo at least two courses of non-steroidal anti-inflammatory drugs (NSAIDs) therapy. In our study, we enrolled axSpA patients both at onset and in a flare who had already been treated with NSAIDs ineffectively. Subsequently, according to the recommendations, they received modified NSAID treatment as another attempt to the first-line drug therapy and were monitored from there. We aimed to identify risk factors for treatment failure after 4 weeks (Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) score ≥ 4) especially amongst zonulin and haptoglobin concentrations, and haptoglobin polymorphism. Treatment failure was observed in 71% of patients, and the following variables were contributed for occurrence of this state: higher zonulin levels, ankylosing spondylitis, X-ray sacroiliitis, magnetic resonance imaging sacroiliitis, long duration of symptoms, high BASDAI, and high value of spinal pain intensity on visual analogue scale. In addition, the following positive correlations were found: haptoglobin concentration with C-reactive protein (r = 0.56; p = 0.0004), and erythrocyte sedimentation rate (r = 0.62; p < 0.0001), as well as between zonulin levels and white blood count (r = 0.5; p = 0.0003). The results of the study presented the identified factors related to the standard treatment failure in axSpA, amongst them zonulin levels. They might be applied to point out the patients for whom the search for a more appropriate method of treatment should be considered.

The failure of biological treatment in axial spondyloarthritis is linked to the factors related to increased intestinal permeability and dysbiosis: prospective observational cohort study.

BACKGROUND: A significant number of patients with axial spondyloarthritis (axSpA) do not respond to biological therapy. Therefore, we decided to investigate the specificity of this group of patients and, in particular, whether haptoglobin (Hp), its polymorphism and zonulin, in addition to other clinical features, are predictors of poor response to biological treatment. METHODS: 48 patients with axSpA who were unsuccessfully treated with standard drugs were converted to biological treatment, and from this time on, a 12-week follow-up was started to assess the failure of biological treatment (Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) decrease < 2 points). Predictors of treatment failure were identified using logistic regression analysis. RESULTS: 21% of subjects had biological treatment failure. Patients who had a higher zonulin level, a history of frequent infections, were older, had inflammatory bowel disease (IBD), had a lower Hp level at the time of inclusion in biological therapy showed an increased risk of treatment failure. CONCLUSIONS: The results of the study support the hypothesis that the effectiveness of biological treatment of axSpA is limited by changed microbiota and intestinal epithelial barrier dysfunction, as an increased risk of biological treatment failure was observed in patients who were older, had higher zonulin level, IBD and repeated courses of antibiotics due to frequent infections. Therefore, starting biological treatment should be followed by reducing intestinal permeability and regulating the disturbed gut microbiome.

Zonulin and copeptin relation to some metabolic markers in school-aged obese children.

BACKGROUND: Using Zonulin and Copeptin as potential obesity markers in children, hasn't yet been focused. AIM: To evaluate the association between serum levels of both Zonulin and Copeptin with the obesity markers, and to assess their role as metabolic disturbance predictors in obese children. METHODS: A case-control study comprised 111 Egyptian children (45 males and 66 females); aged 6-10 years to avoid the effect of puberty (prepubertal). They were classified according to their body mass index (BMI) percentiles into: 72 obese (BMI ≥ 95th ), and 39 control ones (BMI > 15th - <85th ), based on the Egyptian Growth Charts for children and adolescents. Anthropometric parameters and blood pressure were measured, and body composition analysis, lipid profile, Zonulin, and Copeptin levels were assessed. RESULTS: The obese group showed a significantly higher value of Copeptin and a lower value of Zonulin than the control one Also, the obese group showed significant negative correlations between Zonulin and both anthropometric obesity markers and body composition, whereas Copeptin showed significant positive ones. Moreover, significant positive correlations were found between Copeptin and both body weight and fat distribution. Insignificant correlations were observed between both serum Zonulin and Copeptin levels and blood pressure and lipid profile. CONCLUSION: Zonulin and Copeptin cannot be used as metabolic disturbance predictors, among Egyptian children, as they were insignificantly correlated with lipid profile or blood pressure.

Beneficial Effects of Probiotic Lactobacillus paraplantarum BGCG11 on Pancreatic and Duodenum Function in Diabetic Rats.

Diabetes mellitus, as a chronic metabolic disorder, significantly impacts the pancreas and among other organs, affects duodenal function. Emerging evidence suggests that probiotics can exert beneficial effects on gut health and metabolism. In our previous research, we evaluated the probiotic Lactobacillus paraplantarum BGCG11 primarily for its protective properties against diabetic rats' damaged liver and kidneys. In this work, we further examined the effects of probiotic strain BGCG11 on the function of the duodenum and pancreas in diabetic rats. We explored the potential mechanisms underlying the probiotic's effects, focusing on general indicators of diabetes, the architecture and morphology of pancreatic islets, duodenal integrity (measuring the transfer of fluid and serum zonulin level), and the modulation of gut microbiota composition. Our findings reveal the protective and regulatory roles of L. paraplantarum BGCG11 in mitigating diabetes-induced pancreatic and duodenal dysfunction regardless of its application time (pre- or post-treatment), highlighting its therapeutic potential in managing diabetes-related gastrointestinal complications.

Metformin effects on plasma zonulin levels correlate with enhanced physical performance in osteoarthritis patients with diabetes.

PURPOSE: Metformin (MTF) shows promise in protecting against physical decline in osteoarthritis (OA), but how it works remains unclear. We studied MTF's effects on gut permeability and its link to physical performance in OA patients. METHODS: We studied four groups: control (n = 72), OA non-diabetic (n = 58), OA diabetic on MTF (n = 55), and OA diabetic on other anti-diabetics (n = 57). We measured zonulin levels, as intestinal permeability marker, hand-grip strength (HGS), Oxford knee scoring (OKS) to determine OA severity, and short performance physical battery (SPPB) to determine physical functions. RESULTS: Patients suffering from OA showed a reduction in HGS and SPPB scores with raised plasma zonulin than controls, irrespective of disease severity. MTF decreased plasma zonulin levels and improved OKS, gait speed, HGS, and SPPB scores in OA patients. However, OA patients taking other anti-diabetic medications demonstrated higher levels of plasma zonulin, reduced HGS, and SPPB scores. Furthermore, a robust correlation of plasma zonulin and HGS, OKS, gait speed, and SPPB scores in OA patients on MTF was observed. Moreover, we found reduced oxidative stress and inflammation associated with these alterations in OA patients treated with MTF. CONCLUSION: MTF improves HGS and physical performance by lowering zonulin levels, preserving gut permeability in OA patients.

Biochemical Modulators of Tight Junctions (TJs): Occludin, Claudin-2 and Zonulin as Biomarkers of Intestinal Barrier Leakage in the Diagnosis and Assessment of Inflammatory Bowel Disease Progression.

BACKGROUND: Considering the increasing worldwide prevalence of inflammatory bowel disease (IBD), the early diagnosis of this disease is extremely important. However, non-invasive diagnostic methods remain limited, while invasive techniques are the most commonly used in daily practice. Therefore, there is a serious need to find new non-invasive biomarkers of IBD. METHODS: The serum profiles of occludin, claudin-2, and zonulin were assessed in IBD patients using the ELISA method. The levels of the analyzed biomarkers were measured before and after a year of anti-inflammatory treatment, which was a tumor necrosis factor α (TNF-α) inhibitor (adalimumab) in patients with ulcerative colitis (UC) and conventional therapy in patients with Crohn's disease (CD). RESULTS: In IBD patients, the serum level of occludin (p < 0.001) decreased compared to healthy individuals, while the level of claudin-2 (p < 0.001) increased. Additionally, zonulin (p < 0.01) concentration increased in CD patients compared to the control group. The highest diagnostic ability was presented by occludin measurements with the area under the curve (AUC) of 0.959 (95% CI 0.907-1) in UC and 0.948 (95% CI 0.879-1) in CD. Claudin-2 also demonstrated very good ability in diagnosing UC and CD with AUC values of 0.864 (95% CI 0.776-0.952) and 0.896 (95% CI 0.792-0.999), respectively. The ability of zonulin to diagnose CD was estimated as good with an AUC of 0.74 (95% CI 0.598-0.881). Moreover, a significant correlation was identified between C-reactive protein (CRP), claudin-2 (r = -0.37; p < 0.05), and zonulin (r = -0.44; p < 0.05) in UC patients. Treatment with adalimumab improved the level of occludin, claudin-2, and zonulin in UC patients, while anti-inflammatory conventional therapy decreased the concentration of zonulin in CD. CONCLUSIONS: Occludin and claudin-2 measurements present significant utility in diagnosing both UC and CD, while zonulin assessments may be useful in CD diagnosis. Additionally, claudin-2 and zonulin measurements may be helpful in evaluating the intensity of the inflammatory process. Anti-TNF-α treatment improved the value of occludin, claudin-2, and zonulin, indicating its beneficial effect on the integrity of tight junctions in UC.

Effectiveness of rifaximin and probiotics for the correction of intestinal permeability in patients with metabolic-associated fatty liver disease in combination with type 2 diabetes mellitus.

OBJECTIVE: Aim: To investigate the effectiveness of rifaximin and probiotics for the correction of intestinal permeability in patients with metabolic-associated fatty liver disease (MAFLD) in combination with type 2 diabetes mellitus. PATIENTS AND METHODS: Materials and Methods: The prospective interventional randomized investigation included 68 patients with MAFLD in combination with type 2 diabetes, who were examined and divided into the 2 groups of treatment. RESULTS: Results: The serum levels of interleukin (IL) - 6, IL-10 and zonulin, indicators of liver functional activity, liver attenuation coefficient between treatment group vs. control group after 2 weeks, 1 month, 3 and 6 months of therapy were significant differed. The serum levels of IL-6 and zonulin significantly decreasing and increasing of IL-10 in the treatment group after 2 weeks, 1, 3 and 6 months of combined therapy. When comparing of stool short-chain fatty acids concentration between treatment group vs. control group after 2 weeks, 1 month, 3 and 6 months of therapy the levels of acetic, butyric and propionic acids significantly differences and increase in their levels were established. CONCLUSION: Conclusions: The results of the study in dynamics during 6 months show that the additional appointment of rifaximin, multispecies probiotic and prebiotic to metformin in patients with MAFLD and type 2 diabetes led to the elimination of subclinical inflammation, modulation of the permeability of the intestinal barrier and lowering increased intestinal permeability, as well as to the lower serum activity of liver aminotransferases and decrease the stage of steatosis.

Unlocking the link between haptoglobin polymorphism and noninfectious human diseases: insights and implications.

Haptoglobin (Hp) is a polymorphic protein that was initially described as a hemoglobin (Hb)-binding protein. The major functions of Hp are to scavenge Hb, prevent iron loss, and prevent heme-based oxidation. Hp regulates angiogenesis, nitric oxide homeostasis, immune responses, and prostaglandin synthesis. Genetic polymorphisms in the Hp gene give rise to different phenotypes, including Hp 1-1, Hp 2-1, and Hp 2-2. Extensive research has been conducted to investigate the association between Hp polymorphisms and several medical conditions including cardiovascular disease, inflammatory bowel disease, cancer, transplantation, and hemoglobinopathies. Generally, the Hp 2-2 phenotype is associated with increased disease risk and poor outcomes. Over the years, the Hp 2 allele has spread under genetic pressures. Individuals with the Hp 2-2 phenotype generally exhibit lower levels of CD163 expression in macrophages. The decreased expression of CD163 may be associated with the poor antioxidant capacity in the serum of subjects carrying the Hp 2-2 phenotype. However, the Hp 1-1 phenotype may confer protection in some cases. The Hp1 allele has strong antioxidant, anti-inflammatory, and immunomodulatory properties. It is important to note that the benefits of the Hp1 allele may vary depending on genetic and environmental factors as well as the specific disease or condition under consideration. Therefore, the Hp1 allele may not necessarily confer advantages in all situations, and its effects may be context-dependent. This review highlights the current understanding of the role of Hp polymorphisms in cardiovascular disease, inflammatory bowel disease, cancer, transplantation, hemoglobinopathies, and polyuria.

Human coagulation factor X and CD5 antigen-like are potential new members of the zonulin family proteins.

Zonulin is a physiologic epithelial and endothelial permeability modulator. Zonulin increases antigen trafficking from the gut lumen into the bloodstream and in between body compartments, a mechanism linked to many chronic inflammatory diseases. Upon its initial discovery, it was noted that zonulin was not a single protein, but rather a family of structurally and functionally related proteins referred to as the zonulin family proteins (ZFPs). ZFPs are members of the mannose associated serine proteases (MASP) family and are the result of high mutation rates leading to many zonulin polymorphisms. Pre-haptoglobin 2, the precursor of haptoglobin 2, was identified as the first eukaryotic member of the ZFPs, and properdin, a key positive regulator of the alternative pathway, as a second member. In this study, we report two additional proteins that are likely ZFPs. Human coagulation factor X (FX) and CD5 antigen-like (CD5L). Both FX and CD5L recombinant proteins were detected by anti-zonulin antibody in Western immunoblot analysis, and both proteins decreased epithelial barrier competency of Caco-2 cell monolayers as established by the Trans Epithelial Electrical Resistance (TEER) assay. These results indicate that FX and CD5L have structural and functional similarities with previously identified ZFPs and, therefore, can be considered new members of this family of proteins.

Acid Suppression and Antibiotics Administered during Infancy Are Associated with Celiac Disease.

OBJECTIVE: To investigate why certain at-risk individuals develop celiac disease (CD), we examined the association of proton pump inhibitors (PPI), histamine-2 receptor antagonists (H2RAs), and antibiotic prescriptions in the first 6 months of life with an early childhood diagnosis of CD. STUDY DESIGN: A retrospective cohort study was performed using the Military Healthcare System database. Children with a birth record from October 1, 2001, to September 30, 2013, were identified. Outpatient prescription records were queried for antibiotic, PPI, and H2RA prescriptions in the first 6 months of life. Cox proportional hazards regression was used to calculate the hazard ratio (HR) of developing CD based on medication exposure. International Classification of Diseases, Ninth Revision, Clinical Modification codes identified children with an outpatient visit for CD. RESULTS: There were 968 524 children who met the inclusion criteria with 1704 cases of CD in this group. The median follow-up for the cohort was approximately 4.5 years. PPIs (HR, 2.23; 95% CI, 1.76-2.83), H2RAs (HR, 1.94; 95% CI, 1.67-2.26), and antibiotics (HR, 1.14; 95% CI, 1.02-1.28) were all associated with an increased hazard of CD. CONCLUSIONS: There is an increased risk of developing CD if antibiotics, PPIs and H2RAs are prescribed in the first 6 months of life. Our study highlights modifiable factors, such as medication stewardship, that may change the childhood risk of CD.

Disrupted epithelial permeability as a predictor of severe COVID-19 development.

BACKGROUND: An impaired epithelial barrier integrity in the gastrointestinal tract is important to the pathogenesis of many inflammatory diseases. Accordingly, we assessed the potential of biomarkers of epithelial barrier dysfunction as predictive of severe COVID-19. METHODS: Levels of bacterial DNA and zonulin family peptides (ZFP) as markers of bacterial translocation and intestinal permeability and a total of 180 immune and inflammatory proteins were analyzed from the sera of 328 COVID-19 patients and 49 healthy controls. RESULTS: Significantly high levels of circulating bacterial DNA were detected in severe COVID-19 cases. In mild COVID-19 cases, serum bacterial DNA levels were significantly lower than in healthy controls suggesting epithelial barrier tightness as a predictor of a mild disease course. COVID-19 patients were characterized by significantly elevated levels of circulating ZFP. We identified 36 proteins as potential early biomarkers of COVID-19, and six of them (AREG, AXIN1, CLEC4C, CXCL10, CXCL11, and TRANCE) correlated strongly with bacterial translocation and can be used to predict and discriminate severe cases from healthy controls and mild cases (area under the curve (AUC): 1 and 0.88, respectively). Proteomic analysis of the serum of 21 patients with moderate disease at admission which progressed to severe disease revealed 10 proteins associated with disease progression and mortality (AUC: 0.88), including CLEC7A, EIF4EBP1, TRANCE, CXCL10, HGF, KRT19, LAMP3, CKAP4, CXADR, and ITGB6. CONCLUSION: Our results demonstrate that biomarkers of intact or defective epithelial barriers are associated with disease severity and can provide early information on the prediction at the time of hospital admission.

Sustained release of Lactobacillus casei cell wall extract can induce a continuous and stable IgA deposition model.

Mucosal immune regulation is considered a key aspect of immunopathogenesis of IgA nephropathy (IgAN). Direct experimental evidence clarifying the role of intestinal mucosa attributes in IgAN is lacking. In this study, a mouse model was established via multiple low-dose intraperitoneal injections of Lactobacillus casei cell wall extract (LCWE) emulsified with Complete Freund's Adjuvant (CFA). We found continuous and stable deposition of IgA in glomerular mesangial areas, accompanying high circulating levels of IgA and IgA-IgG complexes. Expression of the key extracellular matrix components collagen IV and fibronectin also increased in the mesangial areas of LCWE-induced mice. IgA+ B220+ B-cell proportion increased in the small intestine (SI), Peyer's patches, inguinal lymph nodes, spleen, and bone marrow. The intestinal barrier was dysfunctional in the LCWE-induced mice, and consistent with this, higher levels of serum zonulin (namely prehaptoglobin-2), a regulator of epithelial and endothelial barrier function, were observed in patients with IgAN. Hematoxylin and eosin staining results indicated that immune tissues such as liver, spleen, and lymph nodes showed an inflammatory response and focal lesions. Glucocorticoid methylprednisolone treatment could alleviate serum IgA and IgA-IgG complex levels and mesangial IgA deposition. Taken together, our results indicate that we have successfully constructed a mouse model with IgA deposition in the mesangial areas of the glomeruli and provide evidence for the connection between the intestinal barrier and elevated circulating IgA and IgA-IgG in IgAN. © 2022 The Pathological Society of Great Britain and Ireland.

The use of calgranulin-C (S100A12) and fecal zonulin as possible non-invasive markers in children with inflammatory bowel disease: a clinical study.

Calgranulin-C (S100A12) and zonulin are considered markers of intestinal inflammation. Our aim was to evaluate fecal S100A12 (f-S100A12) and fecal zonulin (f-zonulin) in children with inflammatory bowel disease (IBD), compared to fecal calprotectin (FC) and serum inflammatory markers. We enrolled children with a previous diagnosis of Crohn's disease (CD) and ulcerative colitis (UC). F-S100A12, f-zonulin, and FC were determined by enzyme-linked immunosorbent assay (ELISA). Endoscopic examination was considered in the patients who underwent ileocolonoscopy within 2 weeks from the enrollment. One hundred seventeen children, 39.3% with CD and 60.7% with UC were enrolled. In both CD and UC, there was a significant direct correlation between FC and f-S100A12 levels. In children with CD and UC, both FC and f-S100A12 correlated with markers of serum inflammation. We found difference in FC and f-S100A12 levels between patients in clinical relapse and remission (FC: mean 1027 ± 818 mcg/ml vs 580 ± 695 mcg/ml respectively, p = 0.028; f-S100A12: mean 66.4 ± 48.2 mcg/ml vs 42.7 ± 40 mcg/ml, respectively p = 0.02). Moreover, we found difference in FC between children with endoscopic inflammation and remission (mean 825 ± 779 mcg/ml vs 473.3 ± 492 mcg/ml, respectively p = 0.048), as well as for f-S100A12 (53 ± 43 mcg/ml vs mean 31 ± 33 mcg/ml vs, respectively p = 0.019). No significant results were found for f-zonulin. CONCLUSION: Our data suggest that f-S100A12 and FC are both useful non-invasive biomarkers in the management of pediatric IBD in follow up and in monitoring endoscopic and clinical relapse. WHAT IS KNOWN: • Fecal calprotectin (FC), fecal S100A12 (f- S100A12), and fecal zonulin represent potential noninvasive markers of gut inflammation. • Since S100A12 is predominantly expressed by granulocytes, high levels of f-S100A12 should be more specific for inflammation than FC. WHAT IS NEW: • FC and f-S100A12 were correlated to each other and despite the lack of correlation with disease location, they were associated with endoscopic inflammation and clinical relapse in children with IBD. • No significant correlations were found between f-zonulin and the inflammatory parameters.

From celiac disease to coccidia infection and vice-versa: The polyQ peptide CXCR3-interaction axis.

Zonulin is a physiological modulator of intercellular tight junctions, which upregulation is involved in several diseases like celiac disease (CeD). The polyQ gliadin fragment binds to the CXCR3 chemokine receptor that activates zonulin upregulation, leading to increased intestinal permeability in humans. Here, we report a general hypothesis based on the structural connection between the polyQ sequence of the immunogenic CeD protein, gliadin, and enteric coccidian parasites proteins. Firstly, a novel interaction pathway between the parasites and the host is described based on the structural similarities between polyQ gliadin fragments and the parasite proteins. Secondly, a potential connection between coccidial infections as a novel environmental trigger of CeD is hypothesized. Therefore, this report represents a promising breakthrough for coccidian research and points out the potential role of coccidian parasites as a novel trigger of CeD that might define a preventive strategy for gluten-related disorders in general. Also see the video abstract here: https://youtu.be/oMaQasStcFI.