Course of pulmonary sarcoidosis with and without corticosteriod therapy as determined by pulmonary function studies

Abstract

Serial pulmonary function studies over a six year period in forty-three patients with pulmonary sarcoidosis are reported. Twenty patients received corticosteroid therapy at some time during the course of their illness. The single breath carbon monoxide diffusing capacity (Dco), the vital capacity (Vc), and the maximal mid-expiratory flow rate (MMF) were the principal indices followed. On the basis of the single breath diffusing capacity for carbon monoxide, the patients were divided into two groups: those with mild impairment of pulmonary function (Dco greater than 65 per cent of predicted normal), and those with severe impairment of pulmonary function (Dco 65 per cent of predicted normal or less). Pulmonary function improved spontaneously in only a small percentage of patients with sarcoidosis. Indeed, the diffusing capacity fell in some patients despite complete clearing on the x-ray film of the chest. Corticosteroids produced improvement in all but one of the patients with severe impairment of pulmonary function, but with the cessation of therapy reversion to the previous status occurred in most. Corticosteroid therapy had no consistent beneficial effect on patients in whom pulmonary function was only mildly impaired initially.