Less circulating mucosal-associated invariant T cells in patients with cervical cancer.

OBJECTIVE: Mucosal-associated invariant T cells (MAITs) are important for immune defense against infectious pathogens and regulation of various inflammatory diseases. However, their roles in cancer are rarely reported. Since cervical cancer is one of the diseases involving mucosal tissue, we try to investigate the association between circulating MAITs and cervical cancer. MATERIALS AND METHODS: Blood samples were obtained from patients with cervical cancer (n = 47) and healthy individuals (n = 39). We determined phenotypic MAITs in peripheral blood mononuclear cells (PBMCs) and evaluated the percentage of MAITs in CD3+ cells by flow cytometry. The percentage of MAITs was stratified according to Federation of Gynecology and Obstetrics (FIGO) staging system in patients with cervical cancer. Progression-free survival (PFS) with respect to the amount of MAITs was also analyzed. RESULTS: The percentage of circulating MAITs in patients with cervical cancer was significantly lower than in healthy group (0.987% vs. 4.008%, p < 0.0001). In subgroup analysis, though not statistically significant, it showed a trend of lower percentage of circulating MAITs in cervical cancer patients with FIGO stage II-IV disease than in patients with FIGO stage I disease (0.4045% vs. 1.098%, p = 0.11). A trend of poor PFS in patients with lower circulating MAITs was also noted. CONCLUSION: MAITs play a crucial role in cancer immunity. The decrease of MAITs in peripheral blood is related to cervical cancer. There is a trend of lower percentage of MAITs in advanced stages and lower percentage of MAITs towards poor PFS in patients with cervical cancer.