Potential prognostic value of intracellular cytokine detection by flow cytometry in pulmonary sarcoidosis

In pulmonary sarcoidosis, differential cytokine production in the lungs could be related to variable prognosis of patients at different stages of disease. Twenty patients with pulmonary sarcoidosis (10 at radiographic stage I and 10 at stages II-IV), as well as 10 age-matched healthy volunteers participated in the study. A 4-colour flow cytometric technique was used to measure interferon-γ (IFN-γ), interleukin (IL)-2, tumour necrosis factor-α (TNF-α), IL-4, and IL-13 production in phorbol myristate acetate (PMA)/ionomycin-stimulated CD4+ and CD8+ T cells from bronchoalveolar lavage fluid (BALF) and peripheral blood (PB) of patients, and PB of control subjects. CD4+ T cells from patients showed higher expression of IFN-γ in BALF than in PB. Significant correlations were observed between the percentages of BALF CD4+ and CD8+ T cells expressing intracellular IFN-γ, IL-2, and TNF-α. Stage I patients had lower percentages of IFN-γ-producing CD4+ and CD8+ T cells, as well as TNF-α-producing CD8+ T cells, in BALF (but not in PB) than stage II-IV patients. A decreased TH1 and TC1 response was demonstrated in BALF of patients at stage I of disease, which could explain their anticipated better prognosis.