Comparison of Methods for Identifying Early Methotrexate-Induced Hepatotoxicity in Patients with Rheumatoid Arthritis

Hepatotoxicity may complicate therapy with methotrexate in patients with rheumatoid arthritis. Prevention of cirrhosis may depend upon early identification of liver damage, usually accomplished by serial biopsy. To determine the adequacy of noninvasive methods for identifying hepatotoxicity, 22 sets of data were obtained in patients undergoing therapy with methotrexate for rheumatoid arthritis. Comparisons were made between liver biopsy, hepatocellular enzymes and two noninvasive radioisotopic methods that have been shown to be abnormal in hepatocellula disease: the rate constant of excretion of the 14 C-aminopyrine and the time from injection to peak hepatic affinity of 99m c-diisopropylimidodiacetic acid