Predictive values of various liver function tests with respect to the diagnosis of liver disease.
A prospective study of 181 patients suspected of having liver disease was carried out to determine the relative efficiencies of serum bilirubin (total and direct), alkaline phosphatase (AP), gamma glutamyl transferase (GGT), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) with respect to diagnosis. Liver biopsies, liver scans, abdominal ultrasound, and clinical parameters were also tabulated and used independently to evaluate the patient's hepatic status and to determine the final diagnoses in each case. From the results of these tests for the 60 patients who were diagnosed as having liver disease, and the 87 patients who were felt to be free of liver disease, predictive values of the above tests were established. Data from this study suggests that while direct bilirubin is the most specific test, GGT is the most sensitive and has the fewest false negatives in the diagnosis of liver disease.