[Rational diagnosis in liver diseases].

A rational diagnostic procedure has to be not only scientifically should but also economically reasonable. One has always to ask to what purpose the diagnosis shall serve. The diagnosis is mainly necessary for the treatment of a patient. This includes aiming at a causal therapy, informing the patient about cause and meaning of his symptoms, and also considering prognosis and, if necessary, prophylaxis. In liver disease the following investigations are obligatory: history, signs and symptoms and a minimal set of tests (SGPT, SGOT, gamma-GT, serum bilirubin, urobilinogen in the urine). The next level of diagnostic measures evolves out of several questions: in case of acute disease: etiology (infections; toxic?); evidence of chronic liver disease; differentiation between intra- and extrahepatic cholestasis; evidence of a circumscript lesion of the liver; associated reaction of the liver in connection with other extrahepatic diseases. Serum bilirubin is of relatively little importance except for disturbances of the bilirubin metabolism. The same is true for serum iron except for the diagnosis of hemochromatosis. Blood coagulation tests are of great value for the diagnosis and evaluation of acute and chronic liver disease as are immunologic and serologic investigations (HBsAg, HBcAg, Anti-HBeAg, Anti-HVA, ANF, SMA).