Interstitial vasculitis--interstitial lung disease: case studies.

Six patients with interstitial lung disease were tested in a serial fashion to determine response to medications. All patients had biopsy-proven interstitial lung disease. Exercise testing with measurements of PaO2, PaCO2, and DLCO (the diffusing capacity to carbon monoxide) were made before and after exercise to determine the response to medications. Three patients were treated with corticosteroids and three patients with cytotoxic medications. Results of serial testing of gas transfer correlated with improvement of interstitial lung disease as characterized by resting PaO2, symptoms, and maximal duration of exercise. The value of serial exercise testing is of great help in some, but not all patients. The value of serial testing of patients with interstitial lung disease is discussed.