Abstract Number: PB0507
Meeting: ISTH 2021 Congress
Theme: Hemophilia and Rare Bleeding Disorders » Hemophilia - Clinical
Background: Regulatory T cells (Tregs) play a crucial role in the tolerance of FⅧ. CD4+CD25+CD127–Treg cells, IL-35, IL-10 and TGF- β may be involved in the formation of inhibitors in patients with hemophilia A.
Aims: To determine the expression of Tregs, IL-35, IL-10 and TGF- β in patients with hemophilia A and to explore its possible mechanism in the formation of inhibitors.
Methods: This study included 43 patients with hemophilia A(6 with factor VIII inhibitors and 37 without inhibition of factor Ⅷ) and 20 healthy controls. Among the 43 patients in the hemophilia A group,13 were diagnosed with mild or moderate hemophilia A，whereas 30 were severe. The expression rate of CD4+CD25+CD127–Tregs in peripheral blood was detected by flow cytometry, while the levels of IL-35, IL-10 and TGF- β in plasma were detected by enzyme-linked immunosorbent assay (ELISA).
Results: 
Hemophilia A patients with factor Ⅷ inhibitor feature reduced levels of CD4+CD25+CD127- Treg cells and plasma IL-35
In comparison of healthy controls, hemophilia A patients featured decreased levels of Tregs, for both FVIII inhibitor-positive and -negative group, where the inhibitor-positive group showed the lowest level of Tregs. However, there were no significant differences in the number of Tregs between different disease severity(Fig1 B).Plasma IL-35 and TGF-β concentrations were lower in the inhibitor-positive patients compared to inhibitor-negative patients. The level of plasma IL-10 in patients with hemophilia A was significantly lower than that in healthy controls, but there was no significant difference between inhibitor-positive group and inhibitor-negative group. The level of CD4+CD25+CD127–Treg cells in peripheral blood was positively correlated with the levels of IL-35, TGF- β and IL-10.Serum IL-35 level was positively correlated with serum IL-10 and TGF-β (Fig).
Conclusions: The formation of inhibitors in patients with hemophilia A may be related to the abnormality of CD4+CD25+CD127–Treg cells, and cytokines IL-35 and TGF- β may also be involved.
To cite this abstract in AMA style:
Yan ZY, Yan Z, He H, Xie Y, Wang L, Wu W, Chen S, Yan Y, Yang J. Hemophilia A Patients with Factor Ⅷ Inhibitor Feature Reduced Levels of CD4+CD25+CD127- Treg Cells and Plasma IL-35 [abstract]. Res Pract Thromb Haemost. 2021; 5 (Suppl 2). https://abstracts.isth.org/abstract/hemophilia-a-patients-with-factor-%e2%85%b7-inhibitor-feature-reduced-levels-of-cd4cd25cd127-treg-cells-and-plasma-il-35/. Accessed October 1, 2023.« Back to ISTH 2021 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/hemophilia-a-patients-with-factor-%e2%85%b7-inhibitor-feature-reduced-levels-of-cd4cd25cd127-treg-cells-and-plasma-il-35/