Contributions
Abstract: PB1808
Type: Publication Only
Background
Inhibitors of Factor VIII (FVIII) which arise in up to 35% of patients with hemophilia A causing the most detrimental complications, are usually IgG polyclonal antibodies. Unluckily, the unavailability of the gold standard Bethesda assay that requires expertise in every hemophilia treating centers makes detection of anti FVIII antibodies seems difficult especially for low titer inhibitors.
Aims
To assess the efficacy of ELISA assay for detection of FVIII inhibitors in comparison to the Bethesda test.
Methods
A total of 102 patients with hemophilia A who were screened for inhibitors by APTT then confirmed by Bethesda assay, were tested using enzyme linked immune-sorbent assay (ELISA) for the presence of FVIII specific IgG antibody. Thirty control samples as well as negative and positive samples were included with each run.
Results
Out of all tested samples, 17 (16.7%) were positive by Bethesda assay. Nine samples had high titer (>10 BU), while 8 samples had low titer (<10 BU). In comparison between Bethesda test and ELISA, all the samples that were positive by Bethesda at both high and low titer were detected by ELISA test and all negative samples by Bethesda were also negative by ELISA. Only 6 samples that were positive by Bethesda but at very low titer (< 1BU), were missed by ELISA.
Conclusion
This study results demonstrates strong correlation between the ELISA and Bethesda assay in detecting immune responses to FVIII, as what had been reported in previous literature. ELISA for FVIII antibody detection provides rapid screening test that could be available in small coagulation laboratory.
Session topic: 34. Bleeding disorders (congenital and acquired)
Keyword(s): factor VIII, Inhibitor
Abstract: PB1808
Type: Publication Only
Background
Inhibitors of Factor VIII (FVIII) which arise in up to 35% of patients with hemophilia A causing the most detrimental complications, are usually IgG polyclonal antibodies. Unluckily, the unavailability of the gold standard Bethesda assay that requires expertise in every hemophilia treating centers makes detection of anti FVIII antibodies seems difficult especially for low titer inhibitors.
Aims
To assess the efficacy of ELISA assay for detection of FVIII inhibitors in comparison to the Bethesda test.
Methods
A total of 102 patients with hemophilia A who were screened for inhibitors by APTT then confirmed by Bethesda assay, were tested using enzyme linked immune-sorbent assay (ELISA) for the presence of FVIII specific IgG antibody. Thirty control samples as well as negative and positive samples were included with each run.
Results
Out of all tested samples, 17 (16.7%) were positive by Bethesda assay. Nine samples had high titer (>10 BU), while 8 samples had low titer (<10 BU). In comparison between Bethesda test and ELISA, all the samples that were positive by Bethesda at both high and low titer were detected by ELISA test and all negative samples by Bethesda were also negative by ELISA. Only 6 samples that were positive by Bethesda but at very low titer (< 1BU), were missed by ELISA.
Conclusion
This study results demonstrates strong correlation between the ELISA and Bethesda assay in detecting immune responses to FVIII, as what had been reported in previous literature. ELISA for FVIII antibody detection provides rapid screening test that could be available in small coagulation laboratory.
Session topic: 34. Bleeding disorders (congenital and acquired)
Keyword(s): factor VIII, Inhibitor