Exhaled cytokines in systemic lupus erythematosus with lung involvement

Abstract

Introduction An inflammatory process in systemic lupus erythematosus (SLE) affects many organs including the lungs. Interleukin (IL) 6 and IL-10 are suggested to play an important role in the pathogenesis of SLE. Objectives The aim of the study was to evaluate IL-6 and IL-10 levels in the exhaled breath condensate (EBC) and bronchoalveolar lavage fluid (BALF) of patients with and without pulmonary involvement in SLE. Patient s and methods The study included 34 patients with SLE and 31 healthy controls evaluated using high-resolution computed tomography, pulmonary function tests, the Systemic Lupus Activity Measure (SLAM), and IL-6 and IL-10 measurement (by an enzyme-linked immunosorbent assay) in the BALF and EBC. Result s The mean IL-6 and IL-10 concentrations in the BALF and the IL-10 concentration in the EBC were higher in patients with SLE compared with healthy controls (4.03 ±8.3 vs. 0.62 ±1.2 pg/ml, P <0.0001; 5.54 ±1.85 vs. 0.00 ±1.82 pg/ml, P <0.0001; 8.28 ±2.7 vs. 0.00 ±1.68 pg/ml, P <0.0001, respectively). The IL-10 level in the EBC correlated with SLE activity (r = -0.40, P = 0.019). The SLAM was significantly higher and the total lung capacity was significantly lower in patients with pulmonary manifestation of SLE compared with those without such complications (8.00 ±3.17 vs. 6.00 ±2.31, P = 0.01; 88.00 ±28.29 vs. 112 ±21.08 % predicted, P = 0.01; respectively). In patients with pulmonary involvement, correlations were observed between the IL-10 level in the EBC and the percentage of lymphocytes in the BALF (r = -0.5, P = 0.04). Conclusions Our results indicate that IL-6 and IL-10 are involved in the pathogenesis of SLE. The measurement of IL-10 in the EBC may be a useful biomarker of SLE activity. It is likely that IL-10 protects against pulmonary manifestations of SLE. Copyright 2013 by Medycyna Praktyczna, Kraków.