Prevalence and Correlation with Disease Severit

Abstract

Inhibitors are antibodies that neutralize coagulation factors. They are immunoglobulin’s, arising in congenitally deficient individuals as a result of administration of missing factors. The development of inhibitors remains one of the most serious complications of replacement therapy in haemophilia A patients. Inhibitors makes control of bleeding difficult as they need higher doses of factors or bypassing agents, these are coasty and are not always available. This problem is under estimated and needs further work up to detect the true incidence and the risk factors and their effect on management. Objectives: To determine the prevalence of inhibitors in patients with haemophilia A and correlate the severity of illness with inhibitors level by measuring FVIII level and FVIII inhibitors. Design:Cross sectional prospective study Setting: Haemophilia clinic in Khartoum Teaching Hospital in the period from January to May 2010. Methods: Eighty patients with haemophilia A were included in the study .All patients were males with different disease severities (mild, moderate and severe). Their ages ranged from 3-60 years. Samples were collected from patients for Factor VIII level and inhibitor quantification. Inhibitor quantification was done by Bethesda assay and expressed inBethesda unit (BU).

Results: Seventeen patients (21.3%) were found to have inhibitors, fifteen patients with low titre inhibitors (18.8%) and two of high titre (2.5%). Those with high titre inhibitors had more frequent visits to haemophilia clinic and received more units of factor VIII during the last month. No correlation was found between the severity of the disease and the number of visits during the last year. Inhibitors are most common among severely diseased patients but the correlation between the severity of the disease and the inhibitors was not significant for those with mild and moderate disease. Conclusion: The prevalence of factor VIII inhibitors in this group of patients with haemophilia A was 21.3% (seventeen patients). Fifteen patients of low titre inhibitors (18.8%) and two of high titre (2.5%).This result was significant asthe prevalence of inhibitors was 15-25% in haemophilia A as mentioned in the literature . Inhibitors are most common among severely diseased patients. Those with inhibitors had more frequent visits and receive more amount offactor VIII concentrate during the last month when compared with patients with no inhibitors .