Variations in alveolar cell populations, lymphocyte subsets and NK-cells in different stages of active pulmonary sarcoidosis

BACKGROUND: The type and mode of presentation of pulmonary sarcoidosis (radiologic stage, activity) influence alveolar lymphocyte number and subsets as well as other inflammatory cells. AIM: To investigate the variations in alveolar cells, lymphocyte subsets and NK-cells in different radiological stages of active pulmonary sarcoidosis. METHODS: 85 untreated, newly diagnosed patients (32 male, 53 female), median age 47.2+/-14.7 years were investigated. Patients were classified into chest x-ray stages (33 stage I, 27 stage II, 14 stage III and 11 stage IV disease). Bronchoalveolar lavage was performed with 4 portions of 50 mL. Total cells and cell differentials were counted, while CD3+, CD4+, CD8+, CD19+, CD3-CD16/56+ (NK-cells) and CD3+CD16/56+ (NKT-cells) were determined by flow cytometry. Results: Lymphocytosis was high in all stages. Significant differences were found in: a) CD4 between stages I and II and I and IV. b) CD8 between stages I and IV and c) NK and NKT cells between stages I and III. CONCLUSIONS: Variations were observed in alveolar cells and lymphocyte subsets in different stages of pulmonary sarcoidosis. Cells exhibiting cytotoxic activity were increased with stage progression, CD8 from stage I to IV, NK and NKT cells from stage I to III. These cells may be involved in the inflammatory process regulating granuloma formation.