Bleeding in Young Hemophilia Carriers
Bleeding in Young Hemophilia Carriers
2/8/24 Two papers presented at the European Association for Haemophilia and Allied Disorders (EAHAD) annual meeting looked at the characteristics of bleeding in young carriers (up to age 18). The first study looked at girls in the PedNet registry, a collection of data from hemophilia A or B patients in 19 countries who have factor levels of 25% or lower and were born on or after January 1, 2000. The 23 girls who were included had a median age of 10.1 years. The girls included four severes (3A, 1B), four moderates (2A, 2B) and 15 milds (10A, 5B). Joint bleeds occurred in 75% of the severes, 50% of the moderates and 13% of the milds. The median age at first joint bleed was 1.3 years for the severes, 5.4 years for the moderates and 6.3 for the milds. Five subjects were on prophylaxis (3 severe, 2 moderate). In summary, a significant number of the girls had joint bleeding and needed prophylaxis. It is important to screen girls in hemophilia families early in their lives. [EAHAD abstract PO162]
A similar study from Ireland looked at 217 women (115 As, 62 Bs) with a median age of 9.6 years. The women were from hemophilia families, but not all were carriers. Using 40% of normal factor levels as the cutoff between hemophilia and normal, they found 78.3% of the subjects were in the normal range, 47.5% were in the mild range and 0.5% (one subject) was in the moderate range. There were no subjects with severe hemophilia. (Note that internationally, the upper cutoff for hemophilia is a factor level of 40% of normal. However, the U.S. uses 50% as the cutoff. Therefore, in the U.S., there probably would have been more milds with levels between 40 and 50%.)
Only 17% of the subjects received treatment with the majority of those receiving antifibrinolytics and/or DDAVP (for As only). Only 11% of the As receiving treatment took factor VIII and only 4% of the Bs receiving treatment took factor IX. Overall, 20% of the A carriers received treatment compared to only 9% of the Bs. The average age of the girls receiving treatment was 12 years, compared to 9.6 years for the non-treatment group. Some of the non-treatment group will presumably receive treatment as they grow older. The authors conclude: “Our novel data from a large paediatric hemophilia carrier cohort highlight significant bleeding phenotype and treatment burden in these children.” [EAHAD abstract PO067]