A recent study demonstrated the efficacy of certain immune system cells in restoring immune tolerance in haemophilic mice with factor VIII inhibitors. These are cells are known as FVIII Tregs (Regulatory T cells), i.e. regulatory T lymphocytes that specifically regulate or suppress immune reactions against factor VIII. These cells are normally produced in small quantities by the body, but the Authors of the study developed a technique that allows them to be cultured in vitro and used for therapeutic purposes. The FVIII Tregs obtained in the laboratory, and subsequently infused intravenously into haemophilic mice with inhibitors, were able to suppress the immune reaction against factor VIII and eradicate the inhibitors in all cases except one, in which a significant decrease in the amount of inhibitors produced was nevertheless observed. Other types of Tregs are already being successfully used in the treatment of several diseases, including diabetes, and if the results of this research are confirmed in humans, the use of FVIII Tregs could be a valid therapeutic strategy for the treatment of patients who do not respond positively to ITI (Immune Tolerance Induction), and who account for approximately 30% of subjects with inhibitors.
- Smith B. M. et al, Antigen-specific in vitro expansion of factor VIII-specific regulatory T cells induces tolerance in hemophilia A mice. J Thromb Haemost. 2019; 14