Fatal pulmonary fibrosis complicating low dose methotrexate therapy for rheumatoid arthritis.

We report the fatal disease course of 2 aged patients with rheumatoid arthritis (RA). Both had respiratory complaints after 10-15 weeks of treatment with methotrexate (MTX). After withdrawal of MTX, and despite the use of corticosteroids and ventilatory support, both died of respiratory failure. Post mortem examination showed extensive pulmonary fibrosis, bronchiolitis obliterans, and hyperplasia of type II pneumocytes. To our knowledge, this is the first report of fatal pulmonary fibrosis following short courses of low dose MTX therapy for RA.