Disse inhibitorer er normalt IgG- immunoglobuliner, der retter sig mod faktor VIII prokoagulant- aktiviteten, og som kvantificeres i Bethesda- enheder (BE) pr. ml plasma ved hjælp af Nijmegen- modifikationen af Bethesda- analysen.
These inhibitors are usually IgG immunoglobulins directed against the factor VIII procoagulant activity, which are quantified in Bethesda Units (BUs) per ml of plasma using the Nijmegen modification of the Bethesda assay.