Association Between Appendectomy and Fibrosis Progression in Nonalcoholic Fatty Liver Disease

BACKGROUND A two-hit theory explaining the progression of nonalcoholic fatty liver disease (NAFLD) to nonalcoholic steatohepatitis (NASH) and fibrosis is widely accepted. Endotoxins entering the portal vein from the gut are thought to be one cause of this second hit, and the literature frequently mentions associations between gut-derived endotoxins and progression of fibrosis in NAFLD. The appendix regulates intestinal immunity to protect the gut from the invasion of bacteria and antigens. Appendectomy may thus contribute to progression of fibrosis in NAFLD, but this association has not yet been clarified. We therefore investigated the association between appendectomy and progression of fibrosis in NAFLD. METHODS Fifty two patients with NAFLD who underwent liver biopsy in our department were included in this study. Based on Brunt's scores, patients with NAFLD were classified into a mild fibrosis group and advanced fibrosis group. RESULTS History of appendectomy was found to be significantly more frequent in patients with advanced fibrosis than in patients with mild fibrosis (P = 0.014). Multivariate logistic analysis was conducted with age, sex, albumin, platelet count, steatosis grade, and history of appendectomy as covariates and advanced fibrosis as the dependent variable. Significant differences were identified for platelet count and history of appendectomy, identifying these as independent risk factors for advanced fibrosis in NAFLD patients. The odds ratio for appendectomy history was 39.415 (P = 0.044). CONCLUSIONS History of appendectomy was significantly more frequent in NAFLD patients with advanced fibrosis, suggesting that appendectomy may represent a risk factor for advanced fibrosis in NAFLD.