Saich Rebecca, Chapman Roger
The Department of Gastroenterology, The John Radcliffe Hospital, Headley Way, Headington, Oxford, Oxfordshire, United Kingdom.
World J Gastroenterol. 2008 Jan 21;14(3):331-7. doi: 10.3748/wjg.14.331.
Primary sclerosing cholangitis (PSC) is a chronic progressive disorder of unknown aetiology characterised by chronic inflammation and stricture formation of the biliary tree. Symptoms include itch and lethargy and in advanced cases cholangitis and end-stage liver disease, however increasing numbers of asymptomatic individuals are being identified. The disease is rare in the general population but is strongly associated with inflammatory bowel disease (IBD) affecting up to 5% of patients with ulcerative colitis, with a slightly lower prevalence (up to 3.6%) in Crohn's disease. The strength of this association means that the vast majority (> 90%) of patients with PSC also have IBD, although many may have only mild gastro-intestinal symptoms. Usually IBD presents before PSC, although vice-versa can occur and the onset of both conditions can be separated in some cases by many years. Mean age of diagnosis of PSC is in the fifth decade of life with a strong male predominance. Risk is increased in those with a family history of PSC, suggesting a genetic predisposition and the disease is almost exclusive to non-smokers. The ulcerative colitis associated with PSC is characteristically mild, runs a quiescent course, is associated with rectal sparing, more severe right sided disease, backwash ileitis and has a high risk of pouchitis post-colectomy. Most worrisome is the high risk of colorectal malignancy which necessitates routine colonoscopic surveillance. Cholangiocarcinoma is also a frequent complication of PSC with a 10%-15% lifetime risk of developing this condition. Treatment with high dose ursodeoxycholic acid offers some chemoprotective effects against colorectal malignancy and may decrease symptoms, biochemical and histological progression of liver disease. Small duct PSC patients characteristically have normal cholangiography, and liver biopsy is required for diagnosis, it appears to have a more favourable prognosis. Autoimmune Hepatitis (AIH) is also more prevalent in patients with IBD, with up to 16% of patients with AIH also having ulcerative colitis. A small subgroup of patients have a AIH-PSC overlap syndrome and the management of these patients depends on liver histology, serum IgM levels, autoantibodies, degree of biochemical cholestasis and cholangiography as some of these patients may respond to immunosuppression.
原发性硬化性胆管炎（PSC）是一种病因不明的慢性进行性疾病，其特征为胆管树的慢性炎症和狭窄形成。症状包括瘙痒和乏力，在晚期病例中会出现胆管炎和终末期肝病，然而，越来越多无症状的个体被发现。该疾病在普通人群中较为罕见，但与炎症性肠病（IBD）密切相关，溃疡性结肠炎患者中高达5%患有PSC，克罗恩病患者中的患病率略低（高达3.6%）。这种关联的强度意味着绝大多数（>90%）PSC患者也患有IBD，尽管许多患者可能只有轻微的胃肠道症状。通常IBD在PSC之前出现，尽管也可能相反，并且在某些情况下，两种疾病的发病可能相隔多年。PSC的平均诊断年龄在50岁左右，男性占主导。有PSC家族史的人患病风险增加，提示存在遗传易感性，且该疾病几乎仅见于不吸烟者。与PSC相关的溃疡性结肠炎通常症状较轻，病程呈静止性，与直肠不累及、右侧病情更严重、反流性回肠炎相关，并且在结肠切除术后患袋炎的风险较高。最令人担忧的是结直肠癌的高风险，这需要进行常规结肠镜监测。胆管癌也是PSC的常见并发症，一生中患此病的风险为10%-15%。高剂量熊去氧胆酸治疗对结直肠癌有一定的化学保护作用，并可能减轻症状、改善肝病的生化和组织学进展。小胆管PSC患者的胆管造影通常正常，需要进行肝活检以确诊，其预后似乎较好。自身免疫性肝炎（AIH）在IBD患者中也更为常见，高达16%的AIH患者也患有溃疡性结肠炎。一小部分患者患有AIH-PSC重叠综合征，这些患者的治疗取决于肝组织学、血清IgM水平、自身抗体、生化胆汁淤积程度和胆管造影，因为其中一些患者可能对免疫抑制有反应。
