Gas transfer and pulmonary function tests in women with disseminated lupus erythematosus

BACKGROUND Systemic lupus involves different body organs including lungs. However, there is limited information on the systemic lupus without respiratory symptoms. The aim of this study was to investigate the diffusing capacity of the lung for carbon monoxide in women with disseminated lupus erythematosus and to compare it with a control group. METHODS This prospective study was conducted during 2005 in the Rheumatology Clinic of Alzahra Hospital, Isfahan, Iran. The diffusing capacity of the lung for carbon monoxide and pulmonary parameters were measured using the unrelated samples in 76 female patients with systemic lupus. RESULTS Mean diffusing capacity of the lung for carbon monoxide in patients with lupus was lower than the control group (P ≤ 0.001). The amount of corrected volumetric capacity of carbon monoxide in lungs of patients was significantly different from the control group (P ≤ 0.001). Residual volume and total capacity of lungs in the female patients with lupus were higher than the control group (P ≤ 0.001). CONCLUSION Decreased diffusing capacity for carbon monoxide in lungs of females with systemic lupus without respiratory symptoms is prevalent. It indicates alveolar capillary membrane involvement in these patients. Increased residual volume and total capacity of lungs in these patients can be caused by bronchiolitis.