Low serum level of 25‐OH vitamin D relates to Th17 and treg changes in colorectal cancer patients

BACKGROUND: Serum 25‐hydroxyvitamin D [25(OH)D] level alters in colorectal cancer (CRC) development. Regulatory T (Treg) cells and T‐ helper type 17 (Th17) cells are involved in immune response. Th17‐mediated proinflammatory responses contribute to tumorigenesis, and Treg plays different roles in different periods of CRC. Vitamin D deficiency is associated with significant variations in peripheral immune cells. This study investigated the relationship between Th17 and Treg cells and 25(OH)D level in CRC. METHODS: Ninety‐five CRC patients were included, as well as 80 healthy controls during the same period at the Affiliated Hospital of Jiangnan University. 25(OH)D level was analyzed through electrochemiluminescence (ECLIA). Th17 and Treg levels were evaluated through flow cytometry. Serum levels of interleukin (IL)‐10, IL‐17, IL‐23, and transforming growth factor‐β (TGF‐β), were analyzed through commercial enzyme‐linked immunoassay (ELISA) kits. RESULTS: 25(OH)D levels were downregulated in the serum of CRC patients. Decreased 25(OH)D level contributed to CRC pathogenesis. Decreased 25(OH)D level in CRC correlated with increased Treg and Th17 cell ratios and TGF‐β1, IL‐10, IL‐17, and IL‐23 levels in peripheral blood. CONCLUSION: Decreased 25(OH)D level in the serum of CRC patients had negative correlation with Treg and Th17 ratios and relative cytokines levels.