Effect of methotrexate on pulmonary involvement in patients with rheumatoid arthritis

Objective: The aim of this study is to determine the effects of methotrexate (MTX) therapy on pulmonary involvement in patients with rheumatoid arthritis (RA). Method: Fifty‐five non‐smoking RA patients were included in the study. Routine laboratory investigations, pulmonary function tests (PFT), high resolution computed tomography (HRCT) and arterial blood gas analysis were performed in all of the patients. Randomly dividing the patients into two groups, the first group were given 7.5 mg/week MTX and the second group were given 250 mg/day chloroquine phosphate. At the end of the sixth month all the tests and the analysis were repeated and evaluated by using χ² and Student's t‐test; P < 0.05 was considered statistically significant. Results: At the beginning of the study, HRCT examination revealed 92.7% pulmonary involvement in 55 RA patients. At the sixth month although the RA patients in the chloroquine group did not show any difference, RA patients in the MTX group displayed statistically significant increases in their pulmonary involvement (P < 0.05). Patients in the MTX group also displayed significant decreases at FEV₁/FVC and significant increases at FEV₁ in PFT and O₂ saturation (P < 0.05, P < 0.05 and P < 0.01, respectively). In the chloroquine group we observed significant increases in FEV₁ and vital capacity (P < 0.05). Conclusion: Although the MTX therapy increases the risk of pulmonary involvement in patients with RA, it also increases the ventilation which in turn increases the functional capacity of the patient. Considering the beneficial effect on the radiological progression of the disease, we think that MTX therapy should be taken into account as the first choice in the treatment of RA.