[Profiles of different subsets of CD(4)(+) T cells in chronic idiopathic thrombocytopenic purpura].

OBJECTIVE

To explore the profiles of Th1, Th2, Th17 and Regulatory T (Treg) cells in patients with chronic idiopathic thrombocytopenic purpura (ITP).

METHODS

Samples of peripheral blood were collected from 35 chronic ITP patients (21 in an active stage group, 5 in a non-remission stage group, 9 in a remission stage group) and also from 18 healthy subjects. Flow cytometry was used to measure the intracellular cytokines interferon (IFN)gamma, interleukin (IL)-4 and IL-17 so as to identify the Th1, Th2 and IL-17 cells. Treg cells were identified with CD(4)(+) CD(25)(+) Foxp3(+) cells and uncultured peripheral blood was used to measure the CD(4)(+) CD(+)(25) Foxp3(+) cells with flow cytometry. The concentrations of IFNgamma, IL-4, IL-17 and IL-10 in plasma specimens were detected with ELISA method and its correlation with peripheral platelets counts and megakaryocytes number was analyzed, respectively.

RESULTS

There were no statistically significant differences between any two of the three groups for the percentage of Th1 cells, Th17 cells and Th1/Th17 ratio. The percentage of Th2 cells was (1.01 +/- 0.88)% in active stage and (1.22 +/- 1.04)% in non-remission stage, being significantly decreased than those in remission stage (1.93 +/- 1.04)% (P < 0.05) and the controls (1.86 +/- 0.59)% (P < 0.05). Th1/Th2 ratio was 15.04 +/- 9.67 in active stage, 11.65 +/- 9.32 in non-remission stage, which were significantly higher than those in remission stage (7.17 +/- 5.38, P < 0.05) and the controls (7.02 +/- 3.01, P < 0.05). The percentage of Treg cells was (0.89 +/- 0.58)% in active stage and (1.46 +/- 1.27)% in non-remission stage, being significantly decreased than those in remission stage (6.41 +/- 1.86)% (P < 0.01) and the control (5.73 +/- 0.71)% (P < 0.01). There was no statistic difference between any two of the three groups for plasma IFNgamma and IL-17 level. The plasma IL-4 level was (2.25 +/- 2.05) ng/L in active stage and (2.33 +/- 2.14) ng/L in non-remission stage, being significantly decreased than those in remission stage (6.00 +/- 4.57) ng/L (P < 0.05) and the controls (5.54 +/- 4.00) ng/L (P < 0.05). The plasma IL-10 level was (5.07 +/- 4.10) ng/L in active stage and (5.66 +/- 4.35) ng/L in non-remission stage, being significantly decreased than those in remission stage (10.92 +/- 6.17) ng/L (P < 0.01) and the controls (14.21 +/- 7.31) ng/L (P < 0.01). The plasma level of IL-10 in patients in active stage was positively related to the platelet counts (r = 0.16, P = 0.03).

CONCLUSION

Deficiency 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.