Prevalence of inhibitors and clinical characteristics in patients with haemophilia in a middle‐income Latin American country

Abstract

Introduction Development of inhibitors is the most serious complication in patients with haemophilia (PWH). The prevalence of inhibitors in patients with severe haemophilia A (HA) is approximately 25%‐30%. Inhibitor prevalence differs among populations. Some studies report a prevalence of almost twice in Hispanic as compared to Caucasian patients. Most data available, on the prevalence of inhibitors and their predisposing factors, originate from centres in developed countries. Aim Establish the prevalence of inhibitors of FVIII and FIX in Mexico. Methods This was an observational, cross‐sectional and descriptive study. The records of all patients diagnosed with haemophilia A (HA) or B (HB), with and without inhibitors, were included. Clinical and demographical characteristics of patients with inhibitors were assessed. Statistical analysis was performed using IBM SPSS version 22. The Ethics Committees of the various participating institutions approved this study. Results A total of 1455 patients from the 20 participating centres were recruited, from which 1208 (83.02%) had HA and 247 (16.97%) were diagnosed with HB. The presence of inhibitors in severe HA was reported in 93/777(11.96%), and 10/162 (6.17%) in severe HB. Of them, 91.7% exhibited high titres in HA and 100% in HB. Conclusion In Mexico, the general prevalence of inhibitors varies considerably among centres. This study established a basis of comparison for future development and advances in the treatment and follow‐up of patients. These findings also augment our understanding of risk factors related to inhibitor development.

Diminished cortical bone density of long bones among children with haemophilic arthropathy

“…14 In Mexico, its prevalence varied among centers, ranging from 10% to 25%, it is hypothesized that these differences may result from distributions of F8 polymorphisms. 15 The results of the present study demonstrate a statistically significant difference in the cortical bone density of long bones (radius and tibias) of children with haemophilia compared to healthy peers. To our knowledge, the evaluation of peripheral bones in haemophilia using QUS has only been reported in three studies.…”

“…With regard to the presence of inhibitors in our population, recent publications have reported that the prevalence of inhibitor was almost twice as high in African American (37%) or Hispanic patients (46%), as compared to Caucasians (19%) 14 . In Mexico, its prevalence varied among centers, ranging from 10% to 25%, it is hypothesized that these differences may result from distributions of F8 polymorphisms 15 …”

“…Additionally, the authors found a significant negative correlation between HJHS and SoS measured at the tibia (r = ‐0.455, p = 0.034) 8,9 . In middle‐income, developing countries like Mexico, patients are treated in three different health systems: Instituto Mexicano del Seguro Social (IMSS), Secretaria de Salud (SS) and Instituto de Seguridad y Servicios Sociales para los Trabajadores del Estado (ISSSTE), for these reasons, there is a wide range of access to treatments (cryoprecipitate, fresh frozen plasma, and plasma‐derived, and recombinant factor VIII concentrates) 15 . Recurrent bleeding rates can result in loss of joint range‐of‐motion and chronic arthropathy (expressed as higher HJHS scores) in almost all severely affected patients, as seen in other studies 13,17 …”

FVIII inhibitor surveillance in children with hemophilia A in Indonesia: a report from the Indonesian Pediatric Hematology-Oncology Working Group

“…Repeated administration of exogenous FVIII concentrates can result in antibody formation, which is called an inhibitor [ 1 , 2 ]. Inhibitors are most frequently encountered in patients with severe HA (20–30%) [ 3 , 4 ], with the highest incidence occurring during the first 20–30 days of exposure [ 5 , 6 ]. A post-hoc analysis of the Study on Inhibitors in Plasma-Product Exposed Toddlers (SIPPET) also revealed that the highest rate of inhibitor development occurred during the first 10 days of exposure [ 7 , 8 ].…”

A multicentre real-world data study to assess the bleeding rate and management of patients with haemophilia A and factor VIII inhibitors in Argentina

“…The development of neutralizing antibodies against FVIII concentrates is considered one of the most severe complications associated with haemophilia treatment. After repeated exposure to FVIII replacement therapy, 20-30% of patients with severe haemophilia A and up to 5-10% of patients with mild-moderate haemophilia A develop neutralizing antibodies [3][4][5][6]. Patients with persistent inhibitors are at high risk for uncontrolled bleeding and progressive joint disease, with increased morbidity and decreased quality of life [4].…”