Introduction: This study was conductep to evaluate the involvement of body organs such as the lungs in systemic lupus erythematosus (SLE). Little information exists on lung involvement in lupus patients without respiratory sympwms; we aimed to evaluate the characteristics of lung gas transfer in female SLE patients using carbon monoxide diffusion capacity (DLCO) in comparison with a control group.

Methods: DLCO and lung volume parameters were prospectively measured and analyzed in 76 sequential SLE patients with active disease in our Rheumatology Department in 2005.
Results: The measured transfer factor was lower in female patients with lupus than in the control Group (P£0.001). A similar reduction was observed in volume-corrected transfer factor with stronger statistical significance (P£0.001). Residual volume -and total lung capacity were greater in patients than in the control group (P£0.001).
Conclusions: Reduction of lung transfer factor is a frequent observation in patients with SLE who had no clinical respiratory symptoms. This finding is in favor of alveolocapillary membrane involvement in patients with lupus. Increased residual volume and total lung) capacity may be due to subclinical bronchiolitis.