Factor VIII-specific B-cell response

Factor VIII (FVIII)-specific B-cell responses refer to the adaptive immune process in which B-lymphocytes recognize and produce antibodies against exogenous Factor VIII, a common complication in the treatment of Hemophilia A (1.1.1, 1.3.3). These antibodies, known as inhibitors, neutralize the procoagulant activity of FVIII, leading to treatment failure and increased morbidity (1.3.3, 1.5.3). The response is driven by the activation of FVIII-specific B-cells, which undergo clonal expansion, isotype switching (predominantly to IgG1 and IgG4), and differentiation into long-lived plasma cells and memory B-cells under the influence of T-follicular helper cells and cytokines like B-cell activating factor (BAFF) (1.1.2, 1.4.1, 1.5.1). Therapeutic targeting of these responses involves strategies to induce immune tolerance, such as high-dose Immune Tolerance Induction (ITI), or the use of immunomodulatory agents like rituximab to deplete B-cells (1.2.1, 1.4.1, 1.5.5). Novel approaches under development include FVIII-specific CAR-T cells and bispecific antibodies that selectively target and eliminate the B-cell clones responsible for inhibitor production, aiming to restore the efficacy of FVIII replacement therapy without broad immunosuppression (1.2.2, 1.3.4, 1.5.4).

Other names

Anti-FVIII B-cell responseFVIII inhibitor-producing B-cell responseHumoral immunity to Factor VIIIFVIII-specific B-lymphocyte response

Depletion of B-lymphocytes, inhibition of B-cell survival signals, or specific elimination of FVIII-reactive B-cells to prevent the formation of neutralizing antibodies (inhibitors).