Deficiency of pulmonary Vα24 Vβ11 natural killer T cells in corticosteroid-naïve sarcoidosis patients

SummaryInvariant natural killer T (NKT) cells might contribute to the amplified and prolonged T-cell immune response that characterizes sarcoidosis. Therefore, we want to investigate the frequency and distribution of pulmonary invariant NKT cells in corticosteroid-naïve patients with sarcoidosis. We used multi-parameter flow cytometry with antibodies against CD3, CD4, CD8, CD14, CD19, CD45, CD16/56, TCR Vα24, and TCR Vβ11, on bronchoalveolar lavage fluid (BALF), to examine the frequency and distribution of pulmonary invariant NKT cells in 47 newly diagnosed sarcoidosis patients and in 8 control subjects. The frequencies of BALF Vα24 Vβ11 invariant NKT cells were significantly lower in patients with sarcoidosis in comparison to control subjects. Moreover, lower invariant NKT cell frequencies in patients with sarcoidosis significantly correlated with exaggerated BALF lymphocytosis and CD4 T cell responses. This study demonstrated a pulmonary deficiency in the frequency of a subset of T cells with immunoregulatory function in patients with sarcoidosis.