Differences in frequency and regulation of T follicular helper cells between newly diagnosed and chronic pediatric immune thrombocytopenia

The overactivation of TFH cells may contribute to the immunopathogenesis of pediatric ITP. IL-21 and IL-4 serum levels may affect the differentiation of TFH cells in ITP patients. The aberrant balance between BAFFR-BAFF/TACI-BAFF may be a factor that caused the persistent high expression of ICOSL in pediatric cITP, which consequently lead to the over activation of TFH cells in pediatric cITP.