Abstract
Background: Pulmonary manifestation is one of the most common extra-articular features in rheumatoid arthritis (RA) leading to significant morbidity. Lung function testing helps in identifying the type of respiratory defect. Early detection helps in effective management of the lung involvement in RA.

Aims and Objectives: In this study, we compared the lung function of RA patient with the normal controls.

Materials and Methods: Spirometry was performed in 100 participants (50 RA patients and 50 normal controls). Lung parameters such as forced vital capacity, forced expiratory volume in 1 s, forced expiratory flow in 25-75%, and peak expiratory flow rate were measured. Statistical analysis was performed, P < 0.05 was considered statistically significant.

Result: In this study, restrictive ventilatory defect was seen in 64% of patients, and obstructive ventilatory defect was seen in 10% of patients. Pulmonary function abnormalities are common in asymptomatic rheumatoid patients which were found to be restrictive defect.

Conclusion: Restrictive ventilatory defect may be due to idiopathic pulmonary fibrosis characterized by high levels of rheumatoid factor, antinuclear antibody and deposits of immunoglobulin A, and complement on the alveolar wall. Screening of RA patients with spirometer helps in early detection of pulmonary involvement.