The Role of T Follicular Helper Cells and T Follicular Regulatory Cells in the Pathogenesis of Autoimmune Hemolytic Anemia

Autoimmune hemolytic anemia (AIHA) is an acquired autoimmune disease mediated by antibodies against the patient’s red blood cells. However, the underlying mechanisms for antibody production are not fully understood. Previous studies of etiology and pathogenesis of AIHA mainly focus on autoreactive B cells that have escaped tolerance mechanisms. Few studies have reported the function of T(FH) and T(FR) cells in the process of AIHA. The present study aimed to explore the potential mechanism of T(FH) and T(FR) cells in the pathogenesis of AIHA. With the model of murine AIHA, increased ratios of T(FH):T(FR), elevated serum IL-21 and IL-6 levels, and upregulated Bcl-6 and c-Maf expression were reported. Also, adoptive transfer of purified CD4(+)CXCR5(+)CD25(-) T cells from immunized mice promoted the induction of autoantibody in the AIHA mouse model. Altogether, our data demonstrate the important role of T(FH) cells for control and induction of AIHA. In the light of the key contributions of T(FH) cells to the immune response in AIHA, strategies aimed at inhibiting the T(FH) development or function should be emphasized.