Lung Disease Associated with Methotrexate Therapy

Summary: A patient with diffuse interstitial pneumonitis attributed to methotrexate therapy is reported. Respiratory function tests revealed restrictive lung disease and marked impairment of diffusing capacity. The histological diagnosis was established by open lung biopsy. There was considerable relief of symptoms after administration of corticosteroids, the radiographic abnormalities cleared and tests of lung function showed some improvement. However, residual changes were present when the lungs were examined at autopsy following his death three months later.