Induction of immune tolerance, the future of the registry

Factor VIII (FVIII) inhibitors are IgG antibodies that neutralize the procoagulant activity of FVIII, rendering hemorrhages difficult to manage. There may exist a genetic predisposition with consequent imbalance of T and B cell function. Efforts at inhibitor eradication in the last 20 years have produced a multitude of immune tolerance induction (IIT) protocols with variable outcome. Data derived from the International Registry indicate that inhibitor titer at outset of IIT and dose of FVIII concentrate used are important predictors of success. Future Registry activities should identify optimally standardized IIT regimens designed on the basis of patient likelihood to achieve tolerance and should provide further understanding of T and B cell interaction in the treatment process.