Electrocardiographic Findings Among Asymptomatic Adults With Haemophilia

Abstract Background: People with haemophilia (PwH) are living longer. Therefore, they can develop atherosclerotic cardiovascular disease (ASCVD). Electrocardiogram (ECG) alterations may be a sign of initial ASCVD before the occurrence of symptoms. Objective: To describe the prevalence of resting ECG alterations among PwH adults asymptomatic for ASCVD. Methods: PwH aged ≥ 30 years without previous ASCVD events were considered for the analysis. Resting ECG traces were analysed according to international reference values and the Brazilian Longitudinal Adult Health Study (ELSA-Brasil) results for asymptomatic Brazilian men. Based on the established normal values and using the QT index, we further described the altered ECGs as minor or major changes, according to the Minnesota Code. Differences between prevalences were evaluated by Pearson's χ2 test. Differences between medians were evaluated by the Mann-Whitney U test. A p-value < 0.05 was accepted as statistically significant. Results: A total of 64 PwH were included in the study. Median age was 44 years (interquartile range 35-52). Most patients had haemophilia A (81%) and 47% were severe. The prevalence of obesity, systemic arterial hypertension (SAH), diabetes mellitus (DM), and dyslipidaemia were 16%, 56%, 14%, and 72%, respectively. All the PwH had sinus rhythm, except for one, who had an implanted pacemaker due to idiopathic third-degree atrioventricular block. Altered ECGs were found in 25% and 30% of PwH, according to established criteria and ELSA-Brasil criteria, respectively. Major changes were found in eight (13%) PwH according to the Minnesota Code, including two ECGs with ischaemia-like wall inactivity. Conclusions: The prevalence of altered ECG varied from 25% to 30% among asymptomatic PwH.

Haemophilia B, severe childhood obesity and other extra-haematological features associated with similar 4Mb-deletions on Xq27: Clinical findings, molecular insights and literature update.

INTRODUCTION: Haemophilia B (HB) is associated with pathogenic variants in F9. Hemizygous deletions encompassing the entire F9 and proximate genes may express extra-haematological clinical phenotypes. AIM: To analyse the genotype/phenotype correlations in two unrelated boys with severe early childhood obesity (SCO), global developmental delay (GDD) and similar bleeding phenotype associated with comparable Xq27 deletions spanning the entire F9 and proximate genes, and characterise the pathogenic events estimating the most likely mutational mechanism involved. METHODS: Entire F9-deletions were detected in three hemizygous unrelated probands with HB: two cases, C#1/C#2, presented SCO and GDD and a control patient (Co), who only had severe bleeding symptoms. Dense SNP-array and case-specific STS walking scan allowed characterisation of the deletion breakpoints. Extensive use of bioinformatics, statistics and clinical databases allowed the investigation of genotype-phenotype associations. RESULTS: Patients C#1/C#2 and Co resulted in a complete F9 and additional gene deletions of variable extensions on Xq26.3-Xq27.2 (C#1/C#2/Co: 4.3Mb/3.9Mb/160Kb). C#1/C#2 common deleted gene SOX3 is directly associated with SCO, GDD and pituitary hypothyroidism (PH) whilst C#2 extra-deleted gene MAGEC2 indirectly relates to anal atresia (AA). Breakpoint analysis revealed the involvement of the mechanisms of Alu/Alu recombination for the first time in HB and non-homologous or alternative end-joining. CONCLUSION: Our results represent the first report of unrelated patients with HB, SCO and GDD. This study and the literature update expand the spectrum of clinical findings and molecular insights observed in patients with HB caused by complete F9 and nearby SOX3 and MAGEC2 gene deletions, which may configure a contiguous gene syndrome.

Molecular study of a large cohort of 109 haemophilia patients from Cuba using a gene panel with next generation sequencing-based technology.

INTRODUCTION: In several countries, molecular diagnosis of haemophilia A (HA) and B (HB) is hampered by a lack of resources for DNA analysis. The advent of next-generation sequencing (NGS) has enabled gene analysis at a reasonable cost. AIM: Describe a collaboration between Cuban and Spanish researchers to identify candidate variants and investigate the molecular epidemiology of 106 Cuban haemophilia patients using NGS. PATIENTS/METHODS: The molecular analysis protocol included well-established LR-PCR procedures to detect F8 inversions, NGS with a 30-gene panel to sequence F8 and F9, and multiplex ligation-dependent probe amplification to identify large structural variants. RESULTS: One-hundred and thirty-one candidate variants were identified along F8, F9, and VWF; 72 were unique and 28 (39%) had not been previously recorded. Putative variants were identified in 105/106 patients. Molecular characterization enabled confirmation and reclassification of: 90 HA (85%), 15 HB (14%), and one type 2N VWD (1%). Null variants leading to non-production of FVIII or FIX were common in severe HA (64%), moderate HA (74%), and severe HB (60%), whereas missense variants were frequent in mild HA (57%) and moderate or mild HB (83%). Additional variants in VWF were identified in 16 patients. CONCLUSION: This is the first description of the molecular epidemiology of HA and HB in Cuba. Variants identified in index cases will be of value for local implementation of familial studies and prenatal diagnosis using the molecular approaches available in Cuba. The results of this protocolled genetic study improved the accuracy of the clinical diagnosis and will facilitate management of these patients.

Functional and joint evaluation in a prospective cohort of patients with severe haemophilia.

INTRODUCTION: Arthropathy is the main morbidity of haemophilia. Periodic joint health assessment enables a better understanding of the limitations of these patients. OBJECTIVE: To evaluate the functional and joint performance in patients with haemophilia at one-year follow-up, as well as its association with prophylactic treatment and attendance at scheduled consultations at a haemophilia treatment centre. METHODS: This prospective cohort study included patients with severe haemophilia aged 7 years or more and treated at Fundação Hemocentro de Brasília, Brazil, from January 2014 to December 2018. The Hemophilia Joint Health Score and Functional Independence Score in Hemophilia were assessed at the first consultation and after a one-year follow-up. RESULTS: The study included 69 patients. The mean age at study recruitment was 22.5 ± 4.5 years, 62.3% of patients aged 18 years or older, and 29 patients were receiving primary prophylaxis (38.0%). There was a positive correlation between HJHS and age and a negative correlation between FISH and age. The worsening HJHS was associated with non-primary prophylaxis and non-attendance at scheduled multidisciplinary consultations. The worsening FISH was associated with non-primary prophylaxis. The correlation between FISH and treatment adherence was significant for the delta. CONCLUSION: The older the patient with haemophilia, the higher the probability of a worsening of the HJHS. In the presence of more arthropathies, the older the patient, the worse the FISH. Patients receiving primary prophylaxis show better results in the HJHS and FISH when compared to patients receiving secondary prophylaxis and/or on-demand treatment.

Primary prophylaxis was associated with lower arthropathy in Colombian men with haemophilia B: A longitudinal analysis (2015-2019).

INTRODUCTION: The risk of chronic haemophilic arthropathy (CHA) is related to severity. Evidence suggests that primary prophylaxis (PPr) could reduce CHA incidence and its impact on quality of life. AIM: To evaluate the association between PPr and CHA in Colombian males with haemophilia B (HB) during 2015 to 2019. METHODS: A panel-time analysis was performed with data provided by the National Health System to update a nationwide open cohort of people with congenital coagulopathies. The association was evaluated in a logistic random-effect regression model (LRERM), adjusted by age at diagnosis, prophylaxis dose and frequency, severity, haemarthrosis and high-titre inhibitors. RESULTS: During 2015-2019, a total of 362 men with HB and treated with either, primary, secondary or tertiary prophylaxis were identified. At baseline, CHA prevalence in the cohort was 36.84% (n = 133), median age was 19.0 years (IQR: 10.0-27.0), and median age at diagnosis was 1.0 year (IQR: 0.0-4.0). PPr was prescribed in 37.85% (n = 137), and median dose (IU/Kg/dose) was almost the same for primary vs. secondary/tertiary prophylaxis. Patients in PPr had a lower frequency of severe HB, CHA, haemarthrosis, infectious complications and high-titre inhibitors than those in secondary or tertiary prophylaxis (STPr). In the LRERM, PPr was associated with a significant reduction of 89.70% in the odds of CHA (aOR = 0.103, IC 95%: 0.040, 0.270; P < .001), compared with STPr. CONCLUSIONS: PPr decreased the odds of CHA by 89.70% in males with HB in Colombia. Our findings are consistent with previous studies and support the strategy to prescribe PPr to our patients.

Genetic testing in bleeding disorders.

The aim of molecular genetic analysis in families with haemophilia is to identify the causative mutation in an affected male as this provides valuable information for the patient and his relatives. For the patient, mutation identification may highlight inhibitor development risk or discrepancy between different factor VIII assays. For female relatives, knowledge of the familial mutation can facilitate carrier status determination and prenatal diagnosis. Recent advances in understanding mutations responsible for haemophilia and methods for their detection are presented. For reporting of such mutations, participation in external quality assessment ensures that essential patient and mutation details are routinely included and that pertinent information is incorporated in the interpretation.

Safe switching from a pdFIX (Immunine®) to a rFIX (Bax326).

The ability to switch between coagulation factors safely is of common interest to haemophilia patients and treating physicians. This is the first formal prospective comparative evaluation of safety, efficacy and incremental recovery of a plasma-derived FIX (pdFIX) and a recombinant FIX (rFIX) in the same haemophilia B patients following a switch from pdFIX Immunine® to a recently developed rFIX Bax326 product. Patients (aged <65 years) who completed a pretreatment study which prospectively documented the exposure to Immunine® and monitored FIX inhibitors while receiving prophylactic treatment were transitioned into pivotal (patients aged 12-65 years) and paediatric (patients aged <12 years) clinical studies investigating prophylaxis and treatment of bleeding episodes with Bax326. None of the 44 patients developed inhibitory or specific binding anti-FIX antibodies during the course of the studies. A total of 38 unrelated adverse events (AEs) were occurred in 20/44 (45.5%) subjects during the Immunine® study. Following a switch to Bax326, 51 AEs were reported in 25/44 (56.8%) subjects. The incidence of AEs related to Bax326 treatment (two episodes of dysgeusia in one patient) was low (2.3%); there were no serious adverse reactions. The comparison between Immunine® and Bax326 demonstrated analogous haemostatic characteristics and annualized bleeding rates. Overall, there is direct evidence indicating a safe and clinically effective transition from a pdFIX (Immunine®) to a newly developed rFIX (Bax326(1) ) for prophylaxis and treatment of bleeding in previously treated patients of all age cohorts with severe or moderately severe haemophilia B.

Polimorfismos intragénicos de los genes de los factores VIII y IX y su utilidad en el diagnóstico indirecto de portadoras de hemofilias A y B / Intragenic polymorphisms of factor VIII and IX genes and their utility in the indirect diagnosis of carriers of haemophilias A and B

Las Hemofilias A y B se consideran enfermedades hereditarias ligadas al sexo debidas a mutaciones en los genes que codifican para los factores VIII y IX respectivamente, ocasionando deficiencia en los niveles de la concentración plasmática de estas proteínas y cuyos roles son los de participar activamente en el mecanismo de la coagulación sanguínea. Se han reportado diversas mutaciones responsables de la alteración de estos genes; razón por la cual resulta poco práctico la aplicación de un método de diagnóstico molecular directo para la identificación de mujeres portadoras, por ello, una estrategia diagnóstica apropiada es el análisis indirecto de polimorfismos ligados al gen. El objetivo de este trabajo fue identificar mujeres portadoras en diversas familias con antecedentes de HA y HB residentes del estado Zulia, en Venezuela, caracterizando polimorfismos intragénicos de los genes del factor VIII y factor IX, los cuales permitieron asignar haplotipos y diagnosticar o descartar el estado portador al 95 por ciento de las mujeres que requerían el estudio para HA y al 100 por ciento para HB.

Haemophilia A and B are considered sex-linked inherited diseases caused by mutations in genes that encode factors VIII and IX, respectively. This results in the deficiency of these proteins plasma levels which are actively involved in the mechanism of blood coagulation. It has been reported that several mutations are responsible for the alteration of these genes, which is why the application of a molecular diagnostic method for the direct identification of female carriers is impractical. An appropriate diagnostic strategy is the indirect analysis of polymorphisms linked to the gene. The aim of this study was to identify female carriers in different families with history of HA and HB that live in Zulia State, Venezuela, characterizing intragenic gene polymorphisms of the clotting factors VIII and IX, which helped to identify and assign haplotypes, to diagnose or to exclude the carrying condition, to 95 percent of women who were needing the study for HA and to 100 percent for HB.