OBJECTIVES

To study the expression level of plasma miR-106b-5p in primary immune thrombocytopenia (ITP) and its correlation with the levels of T helper 17 cell (Th17) and regulatory T cell (Treg) and the Th17/Treg ratio.

METHODS

A total of 79 children with ITP (ITP group) and 40 healthy children (control group) were selected as subjects. According to the treatment response, the 79 children with ITP were divided into three groups: complete response (=40), partial response (=18), and non-response (=21). Quantitative real-time PCR was used to measure the expression level of miR-106b-5p. Flow cytometry was used to measure the frequencies of Th17 and Treg, and the Th17/Treg ratio was calculated. The correlation of the expression level of plasma miR-106b-5p with the frequencies of Th17 and Treg and the Th17/Treg ratio was analyzed.

RESULTS

Compared with the control group, the ITP group had significantly higher levels of miR-106b-5p, Th17, and Th17/Treg ratio (<0.05) and a significantly lower level of Treg (<0.05). After treatment, the ITP group had significant reductions in the levels of miR-106b-5p, Th17, and Th17/Treg ratio (<0.05) and a significant increase in the level of Treg (<0.05). Compared with the partial response and non-response groups, the complete response group had significantly lower levels of miR-106b-5p, Th17, and Th17/Treg ratio (<0.05) and a significantly higher level of Treg (<0.05). The correlation analysis showed that in the children with ITP, the expression level of plasma miR-106b-5p was positively correlated with the Th17 level and the Th17/Treg ratio (=0.730 and 0.816 respectively; <0.001) and was negatively correlated with the Treg level (=-0.774, <0.001).

CONCLUSIONS

A higher expression level of miR-106b-5p and Th17/Treg imbalance may be observed in children with ITP. The measurement of miR-106b-5p, Th17, Treg, and Th17/Treg ratio during treatment may be useful to the evaluation of treatment outcome in children with ITP.