[Carriers of haemophilia: Experience of a French university hospital]

Bleeding risk in hemophilia A and B carriers: comparison of factor levels determined using chronometric and chromogenic assays

BACKGROUND

Predicting the bleeding risk in hemophilia A and B carriers (HAC, HBC) is challenging.

OBJECTIVE

The objectives of this study were to describe the bleeding phenotype in HAC and HBC using the standardized Tosetto bleeding score (BS); to determine whether the BS correlates better with factor levels measured with a chromogenic assay than with factor levels measured with chronometric and thrombin generation assays; and to compare the results in HAC and HBC.

METHODS

This ambispective, noninterventional study included obligate and sporadic HAC and HBC followed at a hemophilia treatment center between 1995 and 2019.

RESULTS AND CONCLUSION

The median BS (3, range 0-21 vs. 3.5, range 0-15, P  = ns, respectively) and the abnormal BS rate (35.6% vs. 38.2%, P  = ns) were not significantly different in 104 HAC and 34 HBC (mean age: 38 years, 6-80 years). However, some differences were identified. The risk of factor deficiency was higher in HBC than HAC. Specifically, Factor VIII activity (FVIII):C/Factor IX activity (FIX):C level was low (<40 IU/dl) in 18.3% (chronometric assay) and 17.5% (chromogenic assay) of HAC and in 47% and 72.2% of HBC ( P  < 0.001). Moreover, the FIX:C level thresholds of 39.5 IU/dl (chronometric assay) and of 33.5 IU/dl (chromogenic assay) were associated with very good sensitivity (92% and 100%, respectively) and specificity (80% for both) for bleeding risk prediction in HBC. Conversely, no FVIII:C level threshold could be identified for HAC, probably due to FVIII:C level variations throughout life.

Risk of osteoporotic fractures as a consequence of haemophilia: A nationwide population-based cohort study

AIM

Low bone mineral density occurs more commonly in patients with haemophilia (PWH) than the general population. However, the risk of haemophilia-related osteoporotic fractures has not been well established. We aim to explore the relationship between haemophilia and the development of osteoporotic fractures following haemophilia.

METHODS

This was a nationwide population-based cohort study based on the data in the Taiwan National Health Insurance Research Database (TNHIRD). Patients who were diagnosed with haemophilia were selected. A comparison cohort was formed of patients without haemophilia who were matched according to age and sex. The incidence rate and the hazard ratios (HRs) of new-onset osteoporotic fractures were calculated for both cohorts.

RESULTS

The haemophilia cohort consisted of 75 patients, and the comparison cohort comprised 300 matched control patients without haemophilia. The risk of osteoporotic fractures was higher in the haemophilia cohort than in the comparison cohort (HR = 5.41, 95% confidence interval [CI] = 2.42-12.1, P < 0.001). After adjustments for age, sex, comorbidities, urbanizations and socio-economic status, PWH were 4.37 times more likely to develop osteoporotic fractures (95% CI = 1.88-10.17, P = 0.001) as compared to matched cohort. In addition, the incidence of newly diagnosed osteoporotic fractures was significantly increased after 5-year follow-up durations.

CONCLUSION

Though our study by TNHIRD presented methodologic flaws by its design nature, we observed that haemophilia may increase the risk of osteoporotic fractures and the cumulative incidence was significantly higher for PWH diagnosed more than 5 years. Clinicians should pay particular attention to osteoporotic fractures following haemophilia in PWH as they age.