ABSTRACT
Background: The current treatment of haemophilia is replacement of factor VIII or IX which is effective till development of inhibitor against factors. There has been no study on factor VIII inhibitors in Southern Odisha using Nijmegen朆ethesda assay. This study was planned with objectives to screen factor VIII inhibitors in hemophilia-A patients, to do quantitative estimation of it using Nijmegen-Bethesda assay and to explore factors associated with development of inhibitors. Methods: This cross-sectional study was carried out from September 2016 to August 2018 in Department of pathology, MKCG medical college, Berhampur. Haemophilia-A patients coming to MKCG medical college and registered Haemophilia-A cases under Haemophilia society of Berhampur were included. Patients denying consent and having multiple clotting factors deficiencies were excluded. 1.8ml blood was collected. Mixing study was done to screen factor VIII inhibitors and then in positive cases inhibitors level measured by Nijmegen-Bethesda method. All data were analysed using SPSS (version 16.0).Results: 70 cases of Hemophilia-A patients were studied. Majority (50%) were with severe hemophilia-A. 7 patients developed inhibitors where 3 were high and 4 were low responders. Inhibitor level ranged from 0.8 to 64 Nijmegen-Bethesda units. Patients with severe hemophilia A, more than 10 transfusions and who switched to receive recombinant FVIII from other blood products developed inhibitors which were significant.Conclusions: Severity of hemophilia, increase frequency of transfusion and switching of blood products significantly increases chances of inhibitor development and hence intensive inhibitor screening is needed in these cases. Quantification of inhibitor is needed to monitor treatment and to manage bleeding episodes effectively.
ABSTRACT
El desarrollo de inhibidores anti factor VIII de la coagulación sanguínea es el mayor problema en las complicaciones inherentes al tratamiento de los pacientes con hemofilia A. Este estudio estuvo dirigido a establecer la frecuencia de casos con inhibidor del factor VIII en un grupo de 41 pacientes con hemofilia A que asistieron a la consulta hematológica de un Banco de Sangre, y los factores asociados al nivel de respuesta del inhibidor anti VIII. Se utilizó el método de coagulación para la cuantificación del factor VIII, y ensayo Bethesda para la determinación del inhibidor. Los resultados del estudio mostraron que existió mayor prevalencia de hemofilia A severa (53,7%) seguido del grado leve (34,2%) y el moderado (12,2%). De los pacientes estudiados 27 presentaron inhibidor anti VIII y de este grupo 92,6 % eran de baja respuesta (< 5 UB/L), detectándose con mayor frecuencia en casos con hemofilia severa (36,6%), así como también en aquellos pacientes que tenían un rango de edad entre 1 y 10 años (31,7%) y que habían utilizado de manera continua el factor VIII en dosis inferiores a 1000 UDS, sin encontrar diferencias significativas con dosis mayores utilizadas. Por otro lado, la hemartrosis fue la manifestación clínica más frecuente en los hemofílicos (62,8%). Se concluye que el desarrollo de inhibidores de baja respuesta estuvo relacionado fundamentalmente con la gravedad de la enfermedad, con la edad y con el tiempo de exposición al factor VIII de reemplazo.
ABSTRACT
Factor VIII inhibitors are produced during or after coagulation factor VIII (FVIII) therapy in hemophilia A patients. These inhibitors are usually detected by a modified Bethesda assay or an enzymelinked immunosorbent assay (ELISA). In this study, we used the Bethesda assay to determine the incidence of FVIII inhibitors in 75 fresh plasma samples obtained from 50 hemophilia A patients, and then used ELISA and the Bethesda assay to determine the titres of these inhibitors after the samples had been frozen and thawed. The samples from the screening Bethesda assay were centrifuged and stored at -70degrees C in accordance with the assay guidelines. Subsequently, these samples were thawed and analyzed using ELISA and the Bethesda assay. The incidence of inhibitors in hemophilia A patients was 20.0%. Among the 35 inhibitor-positive samples identified in the screening Bethesda assay, 16 were positive in ELISA while only 4 were positive in the repeated Bethesda assay. In this study, the ELISA technique showed a higher sensitivity than the Bethesda assay in the detection of FVIII inhibitors in samples that were subjected to freezing and thawing procedures; this was because the Bethesda assay could not identify the FVIII inhibitors that were degraded after freezing and thawing.