VPB1167 - Frequency and Quantification of Inhibitors in Congenital Coagulation Disorder Patients - An Experience at Tertiary Care Paediatric Hospital.

Background: Congenital coagulation disorders are found in all racial groups and have a worldwide distribution. Inhibitors can develop in congenital coagulation factor deficiencies. An inhibitor is a polyclonal high affinity immunoglobulin G (IgG) antibody that specifically neutralizes the procoagulant activity of the relevant clotting factor. Bethesda assay is used worldwide as a laboratory investigation to quantify these inhibitors.

Aims: To quantify and calculate the frequency of inhibitors in congenital coagulation disorder patients by using Bethesda assay.

Methods: A cross sectional study carried out in the department of Haematology, Children’s Hospital Lahore, Pakistan for duration of 6 months (from 7th September 2016 to 7th March 2017). Blood samples were taken in Na-citrate (blue top) vials from the study population for PT, APTT, inhibitor screening and quantification by Bethesda assay.

Results: Total 350 children were enrolled in the study out of which 277 (79.1%) were males and 73 (20.9%) were females. The age of these children ranged from 1-15 yrs – 127 (36.3%) patients out of 350 were diagnosed as Hemophilia A, 73 (20.9 %) had Hemophilia B, 38 (10.9%) had rare bleeding disorders &112 (32%) had Von Willebrand disease, 16 (5.77%) patients out of 350 developed inhibitors after getting treatment. All of the 16 patients were from 1-4 yrs of age and were male. Quantifications of inhibitors in these patients was done by Bethesda Assay.

Conclusion(s): Coagulation factor inhibitors can develop against any coagulation factor although the most common are against FVIII (Haemophilia-A). Coagulation factor inhibitor studies includes Bethesda assay to measure inhibitor titre which further guides about treatment.