OBJECTIVE: To investigate potential differences in circulating levels of T regulatory(Treg)/T helper 17(Th17) cells, related inflammatory cytokines and specific transcription factors in healthy individuals and patients with psoriasis conforming to one of three Traditional Chinese Medicine(TCM) syndromes: blood-heat syndrome(BHS), blood-stasis syndrome(BSS) and blood-dryness syndrome(BDS).METHODS: Sixty-seven patients with psoriasis were recruited and assigned to one of three corresponding TCM syndrome groups: BHS(n = 40), BSS(n = 14) and BDS(n = 13 patients).The control group comprised 21 healthy individuals.The circulating levels of Treg/Th17 cells in peripheral blood were assessed using flow cytometry; the levels of inflammatory cytokines interleukin(IL)-10 and tumor necrosis factor(TNF)-α by enzyme-linked immunosorbent assay; and the m RNA expression of T cell-specific transcription factors retinoic acid-related orphan receptor γt(RORγt) and forkhead box P3(Foxp3) by quantitative real-time PCR.RESULTS: The ratio of Th17 cells and the levels of TNF-α and RORγt were all significantly higher in the BHS and BSS groups than the control group(P < 0.05), while the ratio of Treg cells and the levels of IL-10 and Foxp3 mRNA in the BHS group were significantly lower compared with the control group(P < 0.05).No significant differences were seen between the BSS group and the control group.The ratio of Th17 cells and the levels of TNF-α and RORγt in the BDS group were not significantly different from those of the control group; however, the ratio of Treg cells and the levels of IL-10 and Foxp3 were all lower than those in the healthy controls(P < 0.05).CONCLUSION: Compared with healthy individuals,the ratio of Th17 cells and the levels of related cytokines were higher, while the ratio of Treg cells and the levels of related cytokines were lower, in the peripheral blood of psoriasis/BHS patients; corresponding results for the BSS and BDS groups also showed differences.We propose that patterns of differentiation of immunological cells in psoriasis patients are reflected in corresponding TCM blood syndromes.