Abstract Background Primary sclerosing cholangitis associated with inflammatory bowel disease (PSC-IBD) is a distinct and treatment-refractory phenotype of colitis. Oral vancomycin has been proposed as a targeted immunomodulatory therapy, but its intestinal efficacy and safety profile remains uncertain. Methods A systematic review and random-effects meta-analysis was conducted to evaluate intestinal outcomes in adults and children with pre-liver transplant PSC-IBD treated with oral vancomycin. Electronic databases including PubMed, SCOPUS, CENTRAL and Embase were systematically searched for studies reporting clinical remission, endoscopic remission and safety endpoints. Eligible studies were pooled using random-effects models with logit transformation for proportions and inverse-variance methods for continuous data, results were visualised using forest plots. Where possible subgroup analysis will be conducted comparing adult and paediatric cohorts. All analysis was conducted on R 4.5.0 using “meta” package. Results Eight studies encompassing 211 patients met inclusion criteria and were used in our analysis. Eight studies reported clinical remission, yielding a pooled rate of 80% (95% CI 67–89; I² = 54.1%), while five studies demonstrated a pooled endoscopic or mucosal remission of 71% (95% CI 34–92; I² = 82.5%). Biochemical outcomes showed marked improvement: five studies reported faecal calprotectin (FCP) normalisation in 84% (95% CI 55–96; I² = 72.1%). Four studies reported C-reactive protein (CRP) normalisation in 96% (95% CI 85–99; I² = 0%). Subgroup analysis was done for available outcomes stratifying data based on paediatric and adult population, yielding a significant difference only for clinical remission (p = 0.0042). High heterogeneity in several outcomes likely reflects differences in study design, patient populations, treatment duration, and outcome definitions. No included studies reported adverse drug events related to oral vancomycin therapy. Conclusion Oral vancomycin is associated with high rates of clinical, endoscopic, and biochemical remission in pre-liver transplant PSC-IBD. To the best of our knowledge this is the first meta analysis exclusively deriving intestinal outcomes, these findings provide quantitative evidence supporting mucosal benefit. However, the considerable heterogeneity and lack of controlled or safety-focused studies warrants caution during interpretation. Results must be confirmed through large scale randomised control trials studying efficacy and safety endpoints. Conflict of interest: Dey, Pritom: No conflict of interest Da’Costa, Jedd: No conflict of interest Bhanderi, Bhuvan: No conflict of interest Joshi, Deepak: No conflict of interest Kent, Alexandra: I have received honoraria/Consultancy/Sponsorship fees from: Lilly, AbbVie, Coloplast, J&J, Pfizer, Takeda, Tillotts, Dr Falk, Galapagos/AlfaSigma Pavlidis, Polychronis: Advisory services/ speaker fees/ conference sponsorship/ research grants: Abbvie, Alfasigma, DrFalk, J&J, Pfizer, Roche, Takeda, Teva
Dey et al. (Thu,) studied this question.