Systemic immunosuppression depletes peripheral blood regulatory B cells in patients with immune thrombocytopenia

Regulatory B (Breg) cells are potentially implicated in the pathogenesis of immune thrombocytopenia (ITP). We analysed a prospective cohort of newly diagnosed steroid naive ITP patients enrolled in the multicentre FLIGHT trial and found that the numbers of Bregs in their peripheral blood were similar to healthy controls. In contrast, Breg numbers were significantly reduced in ITP patients treated with systemic immunosuppression (glucocorticoids or mycophenolate mofetil). We also demonstrate that glucocorticoid treatment impairs Breg interleukin-10 production via an indirect T-cell-mediated mechanism.

Automated summary

Regulatory B (Breg) cells play an important role in the pathogenesis of immune thrombocytopenia (ITP). The numbers of Bregs are significantly reduced in ITP patients treated with immunosuppression, and glucocorticoid treatment impairs Breg interleukin-10 production via an indirect T-cell-mediated mechanism.