[Effect of Expression Level Changes of M-MDSC to Related Immune Function in Patients with Primary ITP]

To investigate the effect of expression level changes of monocytic myeloid-derived suppressor cells (M-MDSC) to related immune function in the patients with primary immune thrombocytopenia (ITP).

Peripheral blood samples were collected from 53 newly diagnosed ITP patients and 30 healthy volunteers. The quantity of M-MDSC, mRNA levels of Arg-1 and iNOS were detected. CD4⁺T, M-MDSC and CD14⁺HLA-DR⁺ cells were sorted. CD4⁺T cells were marked by CFSE, and the immunosuppressive mechanism of M-MDSC was analyzed.

The count of M-MDSC in peripheral blood of newly diagnosed ITP patients was significantly higher than that in the control group (P < 0.01). However, the expression level of Arg-1 in peripheral blood was not significantly different between the newly diagnosed ITP group and the control group. But the expression level of iNOS in the newly diagnosed ITP patients was significantly higher than that in the control group (P < 0.01). After treatment, the count of M-MDSC in the patients with ITP was significantly lower than before treatment (P < 0.01), which showed that M-MDSC could significantly inhibit the proliferation and secretion of IFN-γ in CD4⁺T cells.

M-MDSC may be related to the disorder of immune tolerance in the patients with ITP, and may become a new index to monitor the curative efficacy of ITP patients.