bile acid sequestrants such as cholestyramine); antibiotics to treat episodes of ascending cholangitis; and vitamin supplements, as people with PSC are often deficient in fat-soluble vitamins (A, D, E, and K).ERCP and specialized techniques may also be needed to help distinguish between a benign PSC stricture and a bile-duct cancer (cholangiocarcinoma).Liver transplantation is the only proven long-term treatment of PSC. Indications for transplantation include recurrent bacterial ascending cholangitis, decompensated cirrhosis, hepatocellular carcinoma, hilar cholangiocarcinoma, and complications of portal hypertension. Not all patients are candidates for liver transplantation, and some experience disease recurrence afterward. The reasons why some patients develop recurrent PSC remains largely obscure, but surprisingly, those without recurrence of disease (hence protected from recurrence) are characterized by an increased presence of the potentially pathogenic  Shigella species. Prognosis
Estimated median survival from diagnosis until liver transplant or PSC-related death is 21.3 years. Various models have been developed to help predict survival, but their use is generally best suited for research and not clinical purposes. A serum alkaline phosphatase less than 1.5 times the upper limit of normal has been associated with better outcomes, but its use in predicting long-term outcomes is unclear. An IgA isotype autoantibody to the pancreatic GP2 protein (anti-GP2 IgA antibody) is the first verified prognostic biomarker in PSC. The role of anti-GP2 IgA in PSC was simultaneously investigated and reported by two research groups, and later confirmed by others.
Primary sclerosing cholangitis and primary biliary cholangitis are distinct entities and exhibit important differences, including the site of tissue damage within the liver, associations with IBD, which includes ulcerative colitis and Crohns disease, response to treatment, and risks of disease progression. Classification
Primary sclerosing cholangitis is typically classified into three subgroups based on whether the small and/or large bile ducts are affected. The subgroups of PSC include:
Classic PSC
Small-duct PSC
PSC associated with autoimmune hepatitis

Management
No pharmacologic treatment has been approved by the U.S. Food and Drug Administration for PSC. Some experts recommend a trial of ursodeoxycholic acid (UDCA), a bile acid occurring naturally in small quantities in humans, as it has been shown to lower elevated liver enzyme numbers in patients with PSC and has proven effective in other cholestatic liver diseases. However, UDCA has yet to be shown to clearly lead to improved liver histology and survival. Guidelines from the American Association for the Study of Liver Diseases and the American College of Gastroenterology do not support the use of UDCA but guidelines from the European Association for the Study of the Liver do endorse the use of moderate doses (13-15 milligrams per kilogram) of UDCA for PSC.Supportive treatment for PSC symptoms is the cornerstone of management. These therapies are aimed at relieving symptoms such as itching with antipruritics (e.g.