Pulmonary function abnormalities in rheumatoid arthritis subjects with no cardiorespiratory symptoms: DLCO does not add to diagnosis

Pulmonary function was assessed in 23 patients with rheumatoid arthritis (RA) of at least 5 years duration and had no cardio-respiratory symptoms, normal chest examination, chest roentgenogram and EKG. Nine patients (39%) had defect in at least one of the lung function test parameter. Only one patients had mild reduction in diffusion capacity (D_LCO) as the sole defect. This specific subgroup of patients had a higher incidence of abnormalities in their PFT and should have spirometry routinely in their follow up. Performing a more expensive test like D_LCO may be unnecessary as a routine test and its use may be restricted to follow up patients in whom specific therapy has been instituted.