Correlation between mixed APTT test and FⅧ inhibitor in children with hemophilia A / 中华检验医学杂志

ABSTRACT

Objective To predict the critical point of FⅧinhibitor development using the results of incubated APTT mixed test by ROC curve .Methods We retrospectively analyzed the results of APTT mixed test and FⅧinhibitor assay in 343 specimens of children with hemophilia A and performed the ROC curve analysis to define the optimum critical point of FⅧinhibitor .Results The area under the ROC curve (AUC) was 0.973 (95% CI 0.960-0.986,P<0.01).For incubated APTT mixed test, the optimum critical point of inhibitor surveillance (Youden value, 0.824) was 39.7s (sensitivity 87.2%, specificity 95.2%), 53.4s was the optimum cut-off point to distinguish low-titer from high-titer FⅧinhibitor (sensitivity94.6%, specificity 95.0%).Conclusion Our results showed that the APTT mixed test could be taken as a screening test to estimate the existence of inhibitor and distinguish high or low titer .