Researchers have made an important discovery that could potentially change the way doctors understand and treat inhibitor development in hemophilia A. The study, “Marginal zone B cells are critical to factor VIII inhibitor formation in mice with hemophilia A,” first appeared in the journal Blood.
Sean R. Stowell, MD, PhD, the study’s senior author, is from the Center for Transfusion Medicine and Cellular Therapies at the Department of Pathology and Laboratory Medicine at Emory University School of Medicine in Atlanta, Georgia. The study found that, in mice, marginal zone B-cells did respond to factor VIII. Marginal zone (MZ) B-cells are primarily found in the spleen, where they serve a vital role in the development of immunity. These cells are involved in the body’s process of identifying and reacting to external antigens in the blood. By demonstrating that MZ B-cells react to factor VIII, researchers have potentially revealed more about how the body forms inhibitors in response to factor VIII treatment.
The researchers wrote that the results “strongly suggest that MZ B-cells play a critical role in initiating FVIII inhibitor formation and suggest a potential strategy to prevent anti-FVIII alloantibody formation in patients with hemophilia A.”
It was also found that by removing MZ B-cells in mice with a genetic factor VIII deficiency they could prevent the formation of inhibitors entirely. However, the authors warned that this process would present a more serious risk in humans. The importance of MZ B-cells and their widespread presence within the body would mean that their total depletion would leave a patient open to a much greater risk of infection.
