Profiles of Th1, Th2, Th17 and Treg Cells in Patients with Chronic Idiopathic Thrombocytopenic Purpura.

Objective: To explore the profiles of Th1,Th2, Th17 and Treg cells in patients with chronic idiopathic thrombocytopenic purpura.

Methods: Samples of peripheral blood were collected from 30 chronic ITP patients ( 9 males and 21 females), aged 41, 21 being in active stage, and 9 in remission stage, and 9 healthy persons in control (3 males and 6 females), aged 36. Peripheral blood was cultured, and activated with PMA/ionomycin when Th1, Th2 and Th17 cells were detected. Flow cytometry was used to measure the intracellular cytokines interferon (IFN)-γ, interleukin (IL)-4 and interleukin (IL)-17 so as to identify the Th1 cells (CD3⁺ CD8⁻ IFN-γ⁺ IL-4⁻ cells), Th2 cells (CD3⁺ CD8⁻ IFN-γ ⁻ IL-4⁺ cells) and IL-17 cells (CD3⁺ CD8⁻ IL-17⁺ cells); Treg cells were identified to CD4⁺ CD25⁺ Foxp3⁺ cells and uncultured peripheral blood was used to measured the CD4⁺ CD25⁺ Foxp3⁺ cells by flow cytometry. The ratios of Th1/Th2 were calculated.

Results: The Th1/Th2 ratio for patients in active stage was 15.04±9.67, significantly higher than those for patients in remission stage (7.17±5.38, P <0.05) and in control (8.47±3.78, P <0.05); the percentage of Treg cells of the patients in active stage was 0.89±0.58%, significantly decreased than those of patients in remission stage (6.41±1.86%, P <0.001) and in control (6.06±0.85%, P <0.001); the percentage of Th17 cells was 1.94±0.77% for patients in active stage, 2.16±0.52% for patients in remission stage and 1.82±0.58% for patients in control, respectively, and there was no statistic significance between them.

Conclusion: Chronic ITP is a Th1 predominant disease; decreased number and function of Treg cells might be one of mechanisms that cause immune regulation dysfunction in chronic ITP; Th17 cells might not play a role in the development of chronic ITP.