Liver biopsy in methotrexate treated psoriatics: a reevaluation

Abstract

A total of 286 liver biopsies were performed in 139 psoriatics on treatment or considered for treatment with methotrexate. In 56 psoriatics included in this study both pre and post methotrexate biopsies were performed, the average methotrexate dose being 936 mg. None of the data showed statistically significant differences between pre and post methotrexate biopsies, with the exception of an increase in fatty infiltration, found when comparing all pre methotrexate biopsies with the total number of latest post methotrexate samples. As expected, alcohol seemed to be significantly associated with liver fibrosis in pre methotrexate biopsies. An earlier intake of potassium arsenite may be an important factor in some patients, although potassium arsenite alone has not been proved to be the cause of liver damage among psoriatics included in this study. While only 1 of 22 psoriatics with a total normal biopsy had been on arsenite, 6 of 18 of the same group of psoriatics who had fibrosis had been on this drug earlier. Although no statistically significant differences related to fibrosis and cirrhosis could be demonstrated between the various groups of psoriatics it should be noted that in 3 cases liver cirrhosis did appear in a biopsy from a methotrexate treated psoriatic who had no signs of fibrosis or cirrhosis in a pre methotrexate biopsy. This incidence is low in relation to the total number of patients treated. The relatively low incidence of cirrhosis found in the present study, as in earlier studies by this group is believed to be due to the use of an intermittent dosage schedule. The study showed that early fibrosis and cirrhosis seem to appear, with very minor abnormalities in laboratory results. This finding indicates the necessity of performing liver biopsies in the control of psoriatics on long term methotrexate therapy. The difference between biopsies from psoriatics and liver biopsies from control patients may indicate that severity of disease may be a complicating factor in the pathogenesis of the liver damage.