Oral vancomycin is not associated with meaningful changes in liver-related endpoints among adults with primary sclerosing cholangitis: A randomized, placebo-controlled trial.

An elevated alkaline phosphatase should first be confirmed to be of hepatic origin: confirm with an elevated GGT, or use ALP isoenzyme fractionation or 5'-nucleotidase to separate liver from non-hepatic (e.g., bone) sources. GGT should NOT be used as a standalone screening test in the absence of otherwise-abnormal liver chemistries, and GGT is not specific (elevated in >50% of alcohol users without overt liver disease). Patients with an elevated ALP, with or without elevated bilirubin, should be tested for primary biliary cholangitis with an anti-mitochondrial antibody (AMA). Once ALP is confirmed to be of hepatic origin, obtain a liver ultrasound to assess the hepatic parenchyma and bile ducts: biliary dilatation suggests an extrahepatic cause, while a non-dilated biliary system suggests an intrahepatic cause. Patients with an elevated ALP, with or without elevated bilirubin, should also be tested for primary sclerosing cholangitis with cholangiography by MRCP (or ERCP) together with serum IgG4, because some extrahepatic cholestatic disease (e.g., PSC, HIV/AIDS cholangiopathy) may not be visible on ultrasound; a history of cholangitis or of colonic inflammatory bowel disease further raises suspicion but is not a prerequisite for obtaining cholangiography. Liver biopsy is generally not required; about 80% of isolated ALP elevations can be diagnosed from history, physical exam, routine labs, and chest X-ray.