CD4+ FoxP3+ T regulatory cell subsets in myasthenia gravis patients

- A lower production of Treg can be observed in thymoma tissue.
- Immunsuppression and thymectomy lead to changes in the distribution of Treg subpopulations in MG patients.
- MG patients are characterized by a lower frequency of highly immunsuppressive CD45RA+ FoxP3low Treg.

Although myasthenia gravis (MG) is a classic autoantibody-mediated disease, T cells are centrally involved in its pathogenesis. In recent years a number of studies have analyzed the role of CD4+ FoxP3+ regulatory T cells (Treg) in the disease with contradictory results. Here, the generation of Treg was significantly reduced in thymoma as compared to thymic hyperplasia and normal thymus tissue (p = 0.0002). In the peripheral blood, Treg subsets classified according to CD49d, HELIOS and CD45RA expression changed after thymectomy and in the long-term course of immunosuppression. Compared to healthy volunteers the frequency of CD45RA+ FoxP3low Treg was reduced in MG patients in general (p = 0.037) and in particular in patients without immunosuppression (p = 0.036). In our study, thymectomy and immunosuppressive treatment were associated with changes in Treg subpopulations. The reduced frequency of CD45RA+ FoxP3low Treg we observed in MG patients might play a role in MG pathogenesis.