Chemokine receptor CXCR3 ligands in bronchoalveolar lavage fluid: associations with radiological pattern, clinical course, and prognosis in sarcoidosis

INTRODUCTION Sustained inflammation in sarcoidosis may lead to lung fibrosis. The activity of numerous chemokines responsible for proliferation and activity of T lymphocytes may play a crucial role in this process and may have predictive value. These include cytokines induced by interferon gamma, such as CXCL9, 10, and 11-ligands of chemokine receptor CXCR3. OBJECTIVES The aim of the study was to estimate the role of CXCR3 ligands in the pathogenesis of sarcoidosis and the predictive value of their concentrations in bronchoalveolar lavage (BAL) fluid. PATIENTS AND METHODS CXCL9, 10, and 11 concentrations in BAL fluid were measured by an enzyme-linked immunosorbent assay in patients with sarcoidosis (n = 59) and controls (n = 34). A total of 46 patients were followed up for 24 months to compare the results between the subgroups with complete remission and with chronic disease. RESULTS Protein-standardized CXCL11 concentrations in BAL fluid from patients with stage II sarcoidosis were higher than in those with stage I (median [interquarile range], 0.95 [0.26-2.39] vs. 0.32 [0.13-0.74] pg/mu g protein, P = 0.02). CXCL10 levels in BAL fluid from patients without Lofgren syndrome were higher compared with those with the syndrome (0.69 [0.51-1.05] vs. 0.40 [0.27-0.70] pg/mu g protein, P = 0.05). None of these markers predicted the chronic course of the disease. CXCL10 levels in BAL fluid correlated with serum angiotensin-converting enzyme, and CXCL11 levels with parenchymal lesions on high-resolution computed tomography. Only nonstandardized CXCL11 concentrations in BAL fluid were higher in sarcoidosis. CONCLUSIONS Our results support the hypothesis that cytokines CXCL9, 10, and 11 may be involved in the pathogenesis of chronic sarcoidosis. However, the lack of notable differences between the sarcoidosis and control groups, as well as the lack of associations with the chronic course suggest that they should not be considered as potential prognostic markers.