Association analysis between T helper type 17 cells, regulatory T cells and mycosis fungoides

Abstract

Objective To investigate the changes of T helper type 17 (Thl7) cells and regulatory T (Treg) cells in different stages of mycosis fungoides.Methods Flow cytometry was performed to determine the percentage of Treg and Th17 cells in peripheral blood from 28 patients with mycosis fungoides (MF),13 patients with large plaque parapsoriasis (PP),17 patients with lichen planus (LP) and 10 healthy human controls,and immunohistochemistry to detect the expressions of forkhead box protein 3 (FOXP3) and interleukin (IL)-17 in tissue specimens from 40 patients with MF,13 with PP,17 with LP and 10 healthy human controls.Statistical analysis was carried out by one-way analysis of variance and Pearson correlation analysis.Results As far as the percentage of Treg cells in peripheral blood was concerned,MF,PP and LP patients were significantly higher than the healthy controls (8.09％ ± 1.68％,6.53％ ± 1.67％ and 2.84 ％ ± 1.16％ vs.1.01％ ± 0.35,all P＜ 0.05),PP patients were higher than LP patients and healthy controls (both P ＜ 0.05),and LP patients were higher than healthy controls (P ＜ 0.05).The percentage of Th17 cells in peripheral blood was significantly increased in MF patients compared with PP patients,LP patients and healthy controls (3.22％ ± 0.82％ vs.2.46％ ± 0.79％,1.38％ ± 0.47％ and 0.59％ ± 0.30％,all P ＜ 0.05).Elevated expression rate of FOXP3 was observed in MF,PP and LP lesions as compared with normal skin (14.94％ ± 4.46％,11.95％ ± 4.72％,6.32％ ± 2.81％ vs.3.43％ ± 1.79％,all P ＜ 0.05),and in MF and PP lesions compared with LP lesions (both P ＜ 0.05),but no significant difference was observed between MF and PP lesions (P ＞ 0.05).There was a significant increase in the expression rate of IL-17 in MF lesions compared with PP lesions,LP lesions and normal skin (15.89％ ± 4.27％ vs.12.02％ ± 3.34％,4.84％ ± 1.93％ and 2.62％ ± 0.89％,all P ＜ 0.05).The Th17/Treg ratio in peripheral blood was significantly lower in MF and PP patients than in LP patients and healthy controls (0.41 ± 0.11 and 0.39 ± 0.12 vs.0.50 ± 0.06 and 0.57 ± 0.19,all P ＜ 0.05).A positive correlation was observed between the proportion of Thl7 cells and Treg cells (r =0.423,P ＜ 0.05) in patients with early-stage MF,but not in those with tumor-stage MF.The proportion of Th17 cells decreased,but that of Treg cells continuously increased in patients with tumor-stage MF.However,no significant difference was noted in the proportion of Thl7 cells or Treg cells among patients with different stages of MF.Conclusion The imbalance between Treg and Th17 cells may be involved in the occurrence and development of MF. Key words: Mycosis fungoides; T lymphocytes, regulatory; Th17 cells