PNEUMONITIS COMPLICATING LOW-DOSE METHOTREXATE THERAPY FOR RHEUMATOID-ARTHRITIS - DISCREPANCIES BETWEEN LUNG-BIOPSY AND BRONCHOALVEOLAR LAVAGE FINDINGS

Two very similar cases of drug-induced pneumonitis complicating treatm ent of rheumatoid arthritis with low-dose methotrexate are presented. Diagnosis was suggested by clinical history and findings, but the bron choalveolar lavage showed a high percentage of neutrophils, an unusual feature in methotrexate-induced pneumonitis. Transbronchial lung biop sies (TBB) confirmed the diagnosis by showing interstitial lymphocytic infiltrate with microgranulomas. Although histologic findings are not strictly pathognomonic, when a differential diagnosis has to be made with infectious and rheumatoid lung disease, TBB appears to be of grea t promise.