Nonsevere hemophilia A: often overlooked, but not forgotten

Nonsevere hemophilia A (NSHA) patients have received relatively little clinical and research attention as compared with their severe counterparts. There is increasing recognition that despite their milder bleeding phenotype, the management of NSHA can be a challenge, with most management decisions largely inferred from severe hemophilia A data. This review focuses on some of the more recent developments in the field of NSHA.

Epidemiologic studies suggest that NSHA remain under-recognized and under-diagnosed globally. As the NSHA population ages, they are susceptible to age-related comorbidities. Large cohort studies of NSHA report that the most common primary cause of death is malignancy. NSHA patients have a lifetime risk of inhibitor development with increasing exposure to factor VIII concentrate. Even so, not all patients with inhibitors will require eradication treatment, irrespective of bleeding phenotype at time of inhibitor development.

As there are currently no evidence-based strategies for inhibitor eradication in NSHA patients, preventive strategies are critical to mitigate inhibitor risk in NSHA. There is a need for active surveillance of NSHA patients by hemophilia treatment centers to address hemophilia-related issues and other age-related comorbidities, in collaboration with primary care physicians and other subspecialists.