该疾病病因尚不清楚。血清自身抗体的高频率的出现,[12]Hov JR, Boberg KM, Karlsen TH. Autoantibodies in primary sclerosing cholangitis. World J Gastroenterol. 2008;14:3781-3791.http://www.ncbi.nlm.nih.gov/pubmed/18609700?tool=bestpractice.com越来越多的自身免疫性疾病,[13]Saarinen S, Olerup O, Broome U. Increased frequency of autoimmune diseases in patients with primary sclerosing cholangitis. Am J Gastroenterol. 2000;95:3195-3199.http://www.ncbi.nlm.nih.gov/pubmed/11095341?tool=bestpractice.com与炎症性肠病的相关性,及特定的HLA单体型的过度表达[14]Donaldson PT, Norris S. Evaluation of the role of MHC class II alleles, haplotypes and selected amino acid sequences in primary sclerosing cholangitis. Autoimmunity. 2002;35:555-564.http://www.ncbi.nlm.nih.gov/pubmed/12765483?tool=bestpractice.com均提示PSC是一种免疫紊乱介导的疾病。然而,由于PSC发病主要见于男性,且对免疫抑制剂治疗无效,因此并非典型的自身免疫性疾病。PSC患者合并某些HLA单倍型和直系亲属有PSC的病史表明遗传因素非常重要。[15]Bergquist A, Montgomery SM, Bahmanyar S, et al. Increased risk of primary sclerosing cholangitis and ulcerative colitis in first-degree relatives of patients with primary sclerosing cholangitis. Clin Gastroenterol Hepatol. 2008;6:939-943.http://www.ncbi.nlm.nih.gov/pubmed/18674735?tool=bestpractice.com
在遗传性易感人群中激发免疫反应的因素尚不明确。可能的因素为结肠炎患者中在结肠激活的淋巴细胞通过肠肝循环转移至肝脏,[16]Grant AJ, Lalor PF, Salmi M, et al. Homing of mucosal lymphocytes to the liver in the pathogenesis of hepatic complications of inflammatory bowel disease. Lancet. 2002;359:150-157.http://www.ncbi.nlm.nih.gov/pubmed/11809275?tool=bestpractice.com和细菌性胆道感染。[17]Olsson R, Bjornsson E, Backman L, et al. Bile duct bacterial isolates in primary sclerosing cholangitis: a study of explanted livers. J Hepatol. 1998;28:426-432.http://www.ncbi.nlm.nih.gov/pubmed/9551680?tool=bestpractice.com