Th17/Treg imbalance in the peripheral blood of patients with psoriasis vulgaris

Abstract

Objective To investigate the imbalance between T helper 17 (Th17) cells and CD4+CD25+ regulatory T (Treg) cells in the peripheral blood of patients with psoriasis vulgaris and its significance. Methods Peripheral blood were collected from 48 patients with psoriasis vulgaris and 32 normal human controls. Pasoriasis area and severity index (PASI) was used to assess the disease severity in these patients. Flow cytometry was performed to determine the percentage of Th17 and Treg cells in peripheral blood, enzyme linked immunosorbent assay (ELISA) to measure the levels of serum interleukin (IL) -17 and IL-10. Results There was a significant increase in the percentage of Th17 cells [(2.70 ± 1.43)% vs. (0.86 ± 0.25)%, P< 0.01] and serum IL-17 level (90.65 ± 29.61 ng/L vs. 48.82 ± 5.49 ng/L, P < 0.01), but a decrease in the percentage of Treg cells [(3.63 ± 1.14)% vs. (7.87 ± 1.26)%, P< 0.01] and serum IL-10 level (17.78 ± 4.09 ng/L vs. 23.76 ± 3.82 ng/L, P <0.01) in patients with psoriasis vulgaris compared with the normal controls. The ratios of Thl7 to Treg cells and serum IL-17 to IL-10 level were significantly higher (0.95 ± 0.76 vs. 0.12 ± 0.06, 5.78 ± 3.19 vs. 2.16 ±0.68, both P < 0.01) in the patients than in the normal controls. The PASI score in patients was positively correlated with the percentage of Th17, serum level of IL-17, Th17/Treg ratio and IL-17/IL-10 ratio (r = 0.97,0.93, 0.99 and 0.97, all P < 0.01), but negatively correlated with the percentage of Treg cells and serum IL-10 level (r = -0.87, -0.90, both P < 0.01). Conclusion The imbalance between Th17 and Treg cells may play an important role in the pathogenesis of psoriasis vulgaris. Key words: Psoriasis; T lymphocytes, helper inducer; T lymphocytes, regulatory; Interleukin-17; Interleukin-10