Prevalence of pulmonary involvement in rheumatoid arthritis and its relationship to some characteristics of the patients. A radiological and clinical study.

The chest radiographs of 309 patients with rheumatoid arthritis (RA) were compared with those of 309 controls. In RA, lung nodules were present in 0.3% and pleural effusion in 0.6% only. Diffuse reticulonodular fibrosis occurred in 4.5% of the RA patients and 0.3% of the controls (p less than 0.001) and was related to subcutaneous nodules, antinuclear antibodies and high Waaler-Rose titres. Diffuse reticular fibrosis occurred in 6.8% and 5.2% respectively and was related only to age greater than 60 and cigarette smoking. Healed tuberculosis occurred in 17.2% of the RA males and in 6.1% of the male controls (p less than 0.025). Sequelae of pleurisy occurred in 16.2% of the RA females and in 8.1% of female controls (p less than 0.025) and was related to involvement of many joints and high ESR. Sequelae of pleurisy occurred in 24.2% of the RA males and 16.2% of the male controls. The pleuropulmonary findings were not related to the therapy given or to the death rate during a mean follow-up period of 5.7 years.