Factors Involved in the Development of Inhibitory Antibodies in Patients with Hemophilia in Colombia: A Case-Control Study.

Background: The appearance of inhibitory antibodies against antihemophilic factors is one of the most serious complications related to hemophilia.

Objective: The objective of this study was to identify variables and factors related to the development of inhibitory antibodies in a group of patients undergoing antihemophilic therapy in Colombia.

Methods: A case-control study in patients with hemophilia treated in Specialized Healthcare Provider Institutions (IPS-E) in 21 cities of Colombia of any age and with a diagnosis of inhibitory antibodies against factor VIII or IX during 2016. Four controls per case paired by age and type of hemophilia were used. Sociodemographic, clinical, and pharmacological variables were identified and analyzed.

Results: Seventeen patients with inhibitory antibodies and 68 controls with hemophilia were identified. The mean age was 28.3 ± 17.8 years. A total of 94.1% had hemophilia A, and 88.2% of the cases and 50.0% of the controls had severe hemophilia; 47.1% of the cases and 54.4% of the controls were receiving prophylaxis with coagulation factors. Multivariate analysis showed that having severe hemophilia (OR:17.0, 95%CI:1.32-219.60) and lack of knowledge of the coagulation factor with which the patient was treated before entering the care program in the IPS-E (OR:8.9, 95%CI:1.82-43.75) were significantly associated with a higher probability of developing inhibitory antibodies.

Conclusion and relevance: Coagulation factors associated with the development of inhibitory antibodies were severe hemophilia and lack of knowledge of the type of factor used prior to entering the follow-up cohort.