Liver biopsies from psoriatics related to methotrexate therapy. 2. Findings before and after methotexate therapy in 88 patients. A blind study.

Eightyeight patients with severe, recalcitrant psoriasis had liver biopsies performed before and after Methotrexate (MTX) therapy. MTX was given for an average of 26 months as a single, weekly, oral dose of 25 mg maximum. The mean cumulative dose was 1733 mg (range 175-4590 mg). A statistically significant increase in the number of pathological post-MTX liver biopsies was found (p less than 0.0001). Of the 88 patients 6 developed cirrhosis and another 5 developed fibrosis, in all 12.5 per cent, during MTX therapy (95 per cent confidence limits for cirrhosis: 3-14 per cent). There was no statistically significant correlation between the number of pathological post-MTX liver biopsy findings in the 88 patients and the following variables one by one: cumulative dose of MTX, duration of MTX therapy and admitted alcoholic intake during MTX therapy. Cirrhosis and fibrosis did not develop statistically more frequently from pathological than normal pre-MTX liver histology (p = 0.062). The liver damage appeared to be due to a multifactorial interaction of straining factors on the liver during MTX therapy. A multifactorial index comprising: cumulative dose of MTX, admitted alcoholic intake during MTX therapy, age, obesity and, if available, pre-MTX liver histology gave an estimate of the probability of developing cirrhosis or fibrosis during treatment of psoriasis with weekly, oral doses of MTX. For use of MTX therapy in psoriasis the following precautions are suggested: MTX therapy should be used only in disabling cases; a pre-MTX liver biopsy and repeat liver biopsies at regular intervals of 1/2-1 year should be performed, alcohol should be prohibited and frequent inquiries should be made about the patient's alcoholic intake; and strong reliance should not be placed on the SGOT as an indicator of abnormal liver histology.