Retrospective analysis of hemophilia B in Turkey: identifying main characteristics and treatment options

Background

Hemophilia B (HB), an X-linked recessive inherited bleeding disorder, exhibits a high prevalence among males.

Objectives

To present the first national cohort of persons with HB to define the demographics, clinical characteristics, and treatment patterns in Turkey.

Methods

This multicenter, retrospective study included 433 alive persons with HB registered in 35 centers between 1961 and 2018. Analyses were performed by age subgroups (0-17 years, 18-64 years, and ≥65 years), disease severity by factor levels (severe, <1 IU/dL; moderate, 1-5 IU/dL; mild, >5 IU/dL). Additionally, patients were stratified based on the initiation year of follow-up at the relevant study center, creating 2 periods: 1993-2006 (referred to as period A) and 2007-2018 (referred to as period B).

Results

Predominantly male (98.6%), the median age at data entry was 22.1 years (n = 429). The majority (49.0%) had moderate HB, followed by severe (30.0%) and mild (15.7%) disease. Of the 377 patients with complete treatment details, 209 (55.4%) were under prophylaxis from their diagnosis onwards, while 79 patients (21.0%) only received on-demand treatment. Additionally, 89 patients (23.6%) initially underwent on-demand treatment and later were switched to prophylaxis. Knees were the primary site of bleeding and the most frequently intervened joints. Most of the major (47.5%) and minor (53.3%) orthopedic procedures were carried out in persons with severe HB, while half of radioactive synovectomy procedures were performed on persons with moderate HB.

Conclusion

This paper describes the demographics, clinical characteristics, and treatments patterns of a large cohort of alive persons with HB on a national scale.