Analysis of Inflammatory Cells with Immunuhistochemical Method in Bronchoalveolar Lavage Fluids of Sarcoidosis Patients

Objective: Sarcoidosis is a systemic disease with an unclear pathogenesis. Pulmonary involvement develops in 50% of cases. Pathologic events like uncontrolled T cell proliferation and release of harmful mediators seen in pulmonary sarcoidosis may be explained with immunologic mechanisms. Pulmonary sarcoidosis has been shown to be related to an increased production of Th1 cytokines and an activation of macrophages. However, cytokine expression in sarcoidosis has not been systematically studied yet. In this study, we aimed to investigate the cell types responsible for initiation and maintanence of inflammatory reactions in the lungs of sarcoidosis patients and expression of cytokines, which are the chemical mediators that may be important for the management of these inflammatory reactions. Material and Methods: In this study, slides prepared in cytocentrifuge from bronchoalveolar lavage (BAL) fluids obtained from 7 sarcoidosis patients and 7 healthy controls were used. All samples were immune stained with CD4 and CD8 monoclonal antibodies and distribution of T-cell subtypes were investigated. Additionally, a T-helper (Th1) cytokine, interferon gamma (IFN gamma) and a macrophage marker, CD68 expression were immunohistochemically analyzed. Results: A significant increase (p=0.002) was detected in lymphocyte count in cytocentrifuge preparates from BAL fluids of sarcoidosis patients compared to healthy controls. The analysis of T lymphocyte subgroups revealed that CD4 (+) helper T cells (Th) (21.59 +/- 0.87%) were higher compared to CD8 (+) supressor T cells (Ts) (10.40 +/- 0.59%). Th/Ts (CD4+/CD8+) ratio was 2/1 in the sarcoidosis group. T cells with IFN gamma expression were encountered in BAL slides of sarcoidosis patients. Giant cells, lymphocytes and polymorphonuclear leucocytes were also present in addition to macrophages in the sarcoidosis group with CD68 expression. Conclusion: Our findings demostrate that T lymphocyte elevation is an important factor contributing to the pathogenesis of sarcoidosis and increased lymphocytes prefer Th1 type cytokine expression.