P023 Serological markers of intestinal barrier function in patients with primary sclerosing cholangitis after liver transplantation

Abstract

Abstract Background Primary sclerosing cholangitis (PSC) is a chronic cholestatic disease associated with inflammatory bowel disease. Liver transplantation (LT) is the only curative treatment for most patients with PSC. Recurrence of PSC (rPSC) is a common long-term complication after liver transplantation in this patient group, affecting graft survival and overall patient survival. There are several lines of evidence indicating that dysregulation of the microbiome and gut barrier dysfunction are key etiologic factors in the pathogenesis of PSC. The aim of this study was to evaluate serological markers of intestinal barrier function in patients with PSC after LT and in control group, to determine potential biomarkers for rPSC. Methods This is a cross-sectional study of patients after LT for PSC at the Institute for Clinical and Experimental Medicine, Prague. The control group consists of patients who underwent liver transplantation for alcohol-related liver disease and/or hepatocellular carcinoma. The rPSC was assessed by MRCP and/or liver biopsy according to the Mayo criteria. IBD status was assessed by endoscopy, biopsy, and faecal calprotectin. We performed ELISA for Zonulin and Reg3a. The Kruskal-Wallis and Mann-Whitney test were used to evaluate the statistical differences. Results A total of 85 patients were included in the study after LT for PSC and 56 controls. rPSC was detected in 18 (21.18%) patients. IBD was diagnosed in 77 (90.5%) patients, of which 3 (3.9%) were categorised as Crohn’s disease. The remainder, 82 patients, were classified as ulcerative colitis, 41.9% with right-sided predominance and 24.3% with back-wash ileitis. The IBD treatment consisted of 5-ASA in 58 patients, azathioprine in 12 patients, vedolizumab in 5 patients, anti-TNFa in 1 patient and 9 patients were on 10 mg or more of prednisone or equivalent. MayoDAI was evaluated at the time of the visit with mean 1.74 (SD ±2.06). There was a significant difference in Reg3a levels between patients with IBD and control subjects (p<0.05, Figure 1.). No significant difference in Reg3a levels was found between rPSC patients and controls (p=0.3). Interestingly, Zonulin levels were significantly higher in the control group than in PSC patients with or without IBD (p<0.001). No significant difference in Reg3a and Zonulin was found between PSC and rPSC patients and between patients in remission and with active IBD. Conclusion Reg3a was associated with PSC-IBD in patients with PSC after LT, but its association with rPSC is unclear and should be investigated in a prospective setting. Zonulin reached higher levels in the control group.