Antibodies to factor VIII in plasma of patients with hemophilia A and normal subjects

摘要: Non-neutralizing factor VIII (FVIII) antibodies (FVIII-Ab) in hemophilia A may be associated with an abnormal clinical response to FVIII concentrates. Patients inhibitors develop noncoagulation FVIII-Ab after the induction of immunotolerance. Natural detected plasma some healthy subjects. The aim this study was analyze presence 53 normal blood donors and 124 patients (18 had a previous history inhibitor, but only 12 inhibitor at moment performed). FVIIII measured using Bethesda method. were analyzed by specific ELISA assay purified from monoclonal concentrate standard containing 26 units (BU) inhibitor. Purified used coat wells microtiter plate incubated dilutions tested. Bound human IgG incubation polyclonal sheep anti.human alkaline phosphatase conjugate, OD405 quantitated. linear fit obtained (by plotting positivity [OD 405nm] versus BU titer) when serial plasma, titers 0.5 or higher, used. Four different levels distinguished assay: Negative (-) 25 BU. eight subjects (15%): three found moderately positive ( + ) five mildly ). No inhibitory activity detectable whole All hemophilic time for FVIII-Ab. In addition, level correlated corresponding six who negative two positive. Twenty additional (16.12%) whom no FVIII-Ab: 16 four +. mean age significantly higher than that group (p < 0.005). conclusion, 17.7% assay. We propose method analysis could A, least complement functional recovery half-life should assessed test show evidence