The plasma acute phase reactant pattern was studied in 124 patients with liver disease and 16 healthy individuals undergoing liver biopsy, alpha 1-Antitrypsin levels were found to correlate positively with the extent of hepatocellular damage, inflammatory activity and total biopsy score. Haptoglobin levels correlate negatively with these parameters and particularly with characteristics conducive to portal hypertension. Orosomucoid and fibrinogen were unaffected by extent of disease and activity. These changes result in a typical acute phase reactant pattern, seen most frequently in viral hepatitis and chronic active hepatitis and less frequently in alcoholic liver disease. When present, it has a high specificity and predictive value for detection of liver disease.