Factor VIII inhibitors. Immune tolerance induction: is it cost effective? We know too little

The development of an inhibitor in a hemophiliac is a serious clinical problem. Many inhibitors have high titers, and thus one cannot guarantee hemostasis. The prevalence of this transfusion-transmitted disease reaches as high as 35%, even with newer products. The costs of product use for inhibitor patients are significantly higher than for those without an inhibitor. For more than 20 years, using the concept of antigen overload, several regimens have existed for the induction of immune tolerance to eradicate these inhibitors. Registries exist reviewing the results of these regimens in the United States and internationally. Although much has been garnered about predictors of outcomes, we have much to learn about who the ideal candidates are, what optimal regimens are, and when to stop, as well as how to maintain a success. The costs of managing an inhibitor patient with and without human immunodeficiency virus (HIV) have caused managed care programs to seriously challenge the use of these regimens. Data are needed to provide the cost benefit of immune tolerance.