Respiratory function in systemic lupus erythematosus, scleroderma, and rheumatoid arthritis

Abstract

13 patients with systemic lupus erythematosus (SLE), 9 with scleroderma (SCL), and 10 with rheumatoid arthritis (RA) were subjected to detailed analysis of respiratory function. The typical functional derangement found was compatible with interstitial damage of the lung and included restrictive ventilatory impairment, reduced transfer factor and compliance, and progressive hypoxemia during exercise, whereas airway conductance and gas distribution were little affected. On average, the SCL group showed the greatest and the RA group the slightest functional impairment, the type of impairment being essentially the same in the different disease groups. Definitely abnormal respiratory function was found also in the absence of radiologically visible changes. Measurement of transfer factor and vital capacity were considered as the most useful tests for evaluation of respiratory function in these diseases.