The lungs in rheumatoid arthritis--a clinical, radiographic and pulmonary function study

To determine the prevalence and spectrum of pulmonary abnormalities in patients with rheumatoid arthritis (RA) in a developing country.

This was a prospective hospital-based survey of a randomly selected group of patients with RA who were seen in a rheumatic diseases unit.

Groote Schuur Hospital and Princess Alice Orthopaedic Hospital, Cape Town.

A group of 104 patients with RA were randomly selected from a total of 330 patients with RA who were seen in the rheumatic diseases unit. All the patients were interviewed and a clinical assessment, chest radiographs and pulmonary function tests were performed.

Fifty-six patients (53.8%) had evidence of one or more current or previous pulmonary diseases: rheumatoid nodule in 1 (1%), bronchiectasis in 2 (1.9%), fibrosing alveolitis in 5 (4.8%), pneumonia in 5 (4.8%), asthma in 9 (8.7%), pleural disease in 17 (16.3%) and tuberculosis in 25 (24%). Excluding patients who were smokers or ex-smokers or who had coexistent pulmonary disease, there were 20 patients (19.2%) who had pulmonary abnormalities that could be attributed to RA: rheumatoid nodule in 1 (1%), fibrosing alveolitis in 5 (4.8%) (1 of whom also had pleural disease), pleural disease alone in 8 (7.7%), diffusion defect in 5 (4.8%) and airways obstruction in 1 (1%).

This study provides clinical and lung function criteria that allow a clinically useful stratification of abnormalities in relation to a spectrum of common causes of pulmonary dysfunction that need to be distinguished from pulmonary abnormalities caused by RA. Pulmonary abnormalities are common and about 20% of RA patients may have an abnormality related to RA.