Differenzialdiagnose Ikterus

Jaundice is the result of increased serum bilirubin levels. An initial differentiation of the underlying causes can be made by distinguishing increased conjugated and non-conjugated serum bilirubin and the findings of abdominal ultrasound examination. This combined approach enables a first classification into extrahepatic causes, hepatocellular dysfunction and intrahepatic and extrahepatic forms of cholestasis. In each diagnostic category of jaundice the differential diagnosis can be improved by additional imaging techniques comprising helical CT scanning, MRCP or ERCP, targeted laboratory tests and finally a liver biopsy. Specific difficult-to-diagnose cholestatic diseases include primary biliary cirrhosis (PBC), primary sclerosing cholangitis (PSC), autoimmune hepatitis PBC and PSC overlap syndromes, IgG4 cholangiopathy and familial deficiency of biliary transporters due to mutations in the ATP8B1, ABCB11, ABCB4 and Jag1 genes. Molecular genetic testing enables these familial conditions to be differentiated.