Aberrant phosphorylation of signal transducer and activator of transcription 3 protein of the CD4+ T cells in patients with primary immune thrombocytopenia

Dexamethasone suppresses the Th17/1 cell polarization in the CD4+ T cells from patients with primary immune thrombocytopenia

INTRODUCTION

Primary immune thrombocytopenia (ITP) is an acquired autoimmune disease with increased Th17 cells in peripheral blood. Th17/1 cells, which were recently characterized as a new differentiated Th17 lineage secreting IL-17 and IFN-γ, play an important role in the pathogenesis of multiple autoimmune diseases. In this study, we investigated whether Th17/1 cells are involved in the pathogenesis of ITP.

MATERIALS AND METHODS

Peripheral blood was obtained from 44 ITP patients and 50 healthy controls. The percentages of T cell subsets were evaluated. We also detected molecular signature of Th17/1 cells in CD4⁺ T cells. Besides, CD4⁺ T cells from ITP patients were treated with dexamethasone, the inhibitor of NF-κB, or rapamycin to evaluate the impact and mechanism of dexamethasone treatment on Th17/1 cells.

RESULTS

We found an elevated percentage and an enhanced specific molecular signature of Th17/1 cells in CD4⁺ T cells in ITP patients. The percentage of Th17/1 cells was correlated positively with Th17 cells in ITP patients and healthy controls. The percentage of Th17/1 cells was correlated with corticosteroid resistance. Dexamethasone reversed the molecular signature of Th17/1 cells and decreased the percentage of Th17/1 cells in vitro. Treatment of dexamethasone and the inhibitor of NF-κB suppressed the phosphorylation of STAT3, while dexamethasone treatment also inhibited the phosphorylation of NF-κB p65.

CONCLUSIONS

Our data suggested Th17/1 cells may contribute to the pathogenesis of ITP and dexamethasone could inhibit Th17/1 cells through NF-κB/STAT3 pathway. These results may provide a potential therapeutic strategy of correcting the Th17/1 cell deviation in ITP.

A biomarker and therapeutical target in immune thrombocytopenia: TNF receptor-associated factor 6

Background: Immune thrombocytopenia (ITP) is an acquired disease characterized by various pathogenetic mechanisms. We aimed to evaluate the value of TRAF6 as a biomarker of pathogenesis in ITP. Methods: 85 newly diagnosed ITP patients and 85 controls were included. Results: In the patient group, mean TRAF6 level was 2348 pg/ml and in the control group, TRAF6 level was 25.57 pg/ml. In corticosteroid-responding patients, TRAF6 levels were lower than nonresponding patients. Discussion: TRAF6 levels were observed to be higher than healthy controls, which suggest a solid relation with ITP pathogenesis. The observation that in patients who present with high TRAF6 levels, there was a significant corticosteroid refractoriness and responsiveness.