Circulating Th22 cells, as well as Th17 cells, are elevated in patients with renal cell carcinoma.

T-helper (Th) 22 cells serve an essential role in different types of tumors and autoimmune diseases. No research has been conducted to study the role of Th22 cells in the pathogenesis of renal cell carcinoma (RCC). We aimed to evaluate the prognostic value of circulating Th22, Th17, and Th1 cells in RCC patients. Thirty-two newly diagnosed RCC patients and thirty healthy controls were enlisted in the research. Their peripheral blood was collected, and the frequencies of circulating Th22, Th17, and Th1 cells were detected by flow cytometry. Plasma IL-22 concentrations were examined by an enzyme-linked immunosorbent assay (ELISA). Quantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to identify the mRNA expression levels of aromatic hydrocarbon receptor (AHR) and RAR-associated orphan receptor C (RORC) in peripheral blood mononuclear cells (PBMC). Compared with the healthy control group, the frequency of circulating Th22 and Th17 cells and concentrations of plasma IL-22 were significantly increased in RCC patients. However, there was no significant difference in the frequency of Th1 cells. A positive correlation between Th22 cells and plasma IL-22 levels was found in RCC patients. Also, there was a significant positive correlation between Th22 and Th17 cells in RCC patients. An up-regulated expression of AHR and RORC transcription factors were also observed in RCC patients. As tumor stage and grade progressed, the frequencies of Th22 and Th17 cells and the level of plasma IL-22 significantly increased. Meanwhile, there was a positive correlation between Th22 and Th17 cells and RCC tumor stage or grade. Furthermore, patients with high Th22 or Th17 cells frequency displayed a decreased trend in survival rate. Our research indicated that the increased circulating Th22 and Th17 cells and plasma IL-22 may be involved in the pathogenesis of RCC and may be involved in the occurrence and development of tumors. Th22 cells, plasma IL-22, and Th17 cells may be promising new clinical biomarkers and may be used as cellular targets for RCC therapeutic intervention.