Pulmonary function in systemic lupus erythematosus patients without respiratory symptoms.

Pulmonary function was studied in 22 patients with systemic lupus erythematosus without pulmonary clinical symptoms. The most striking features were: a) a restrictive functional pattern with hyperinflation, characterized by a decreased vital capacity and increased residual volume; b) alteration of the elastic properties of the lung, with increased pulmonary elastance; c) impairment of the alveolar-capillary gas transfer capacity, with very significant changes of the CO diffusion and arterio-alveolar gradients for O2 and CO2. No marked differences were found in functional disturbance among patients in the active or inactive phase of the disease.