Cholestasis in adults (raised ALP and GGT)

• No tests in the community: refer the same day (emergency department, gastroenterologist).
• Warning signs: fever with rigors or right upper quadrant pain (cholangitis), unexplained jaundice, confusion, dilated bile ducts on ultrasound.

• Abdominal ultrasound (not a laboratory test), first.

Fasting laboratory tests

• Alkaline phosphatase, GGT, total and conjugated bilirubin, AST, ALT
• Antimitochondrial antibodies
• Antinuclear antibodies on HEp-2 cells (rim-like or multiple nuclear dots pattern)if needednon-French guidelineImmediately, with anti-mitochondrial antibodies: EASL 2017 recommends looking for both in any patient with unexplained cholestasis ^[5]. Otherwise, they are requested if anti-mitochondrial antibodies are negative (next tab).
• IgM
• PT (if jaundice or prolonged cholestasis)if needednon-French guidelineJaundice or chronic cholestasis: PT may lengthen through vitamin K deficiency (fat malabsorption) ^[4].
• Hepatitis B serologyif needednon-French guidelineMixed pattern (raised transaminases), viral risk factor (country of origin, drug use): viral hepatitis can be cholestatic and is part of the basic aetiological work-up of the BSG ^[2,4].
• Hepatitis C serologyif needednon-French guidelineMixed pattern (raised transaminases), viral risk factor (country of origin, drug use): viral hepatitis can be cholestatic and is part of the basic aetiological work-up of the BSG ^[2,4].
• β-hCG (woman of childbearing potential)if needednon-French guidelineWoman of childbearing potential: look for pregnancy and intrahepatic cholestasis of pregnancy (pruritus in the 2nd and 3rd trimesters) ^[2,6].

Laboratory tests

• Antinuclear antibodies on HEp-2 cells (rim-like or multiple nuclear dots pattern)
• IgG
• ANCA (if inflammatory bowel disease or suspected sclerosing cholangitis)if neededAssociated IBD, young man, biliary-type flares: pointer to primary sclerosing cholangitis; p-ANCA poorly specific, especially in IBD ^[7].
• IgA anti-tissue transglutaminase antibodies (tTG-IgA)if neededSuspected primary sclerosing cholangitis: possible association with coeliac disease, looked for by the AFEF in the initial work-up ^[7].
• Total IgAif neededSuspected primary sclerosing cholangitis: possible association with coeliac disease, looked for by the AFEF in the initial work-up ^[7].
• Anti-smooth muscle antibodies (if unexplained intrahepatic cholestasis)if needednon-French guidelineUnexplained intrahepatic cholestasis with negative anti-mitochondrial antibodies: the ACG (2017) looks for anti-smooth muscle antibodies together with anti-mitochondrial and antinuclear antibodies (primary biliary cholangitis, autoimmune cholangiopathy) ^[6], and the BSG includes them in the aetiological work-up of any abnormal liver test ^[4]; with markedly raised transaminases or IgG, they help to identify an associated autoimmune hepatitis ^[9].
• MR cholangiography (not a laboratory test): most often prescribed by the hepatologist.