In view of the available literature summarized in this review, it can be concluded that the carbohydrate structures on FVIII and VWF play a crucial role in the life-cycle of both proteins. However, many questions still remain unanswered. What is the role of carbohydrate-binding proteins like Galectins and Siglecs in this regard? How do differences in glycosylation between plasma-derived
and recombinant proteins translate in the physiological response to these preparations? For instance, Qadura et al. [44] recently reported that pd-FVIII and rFVIII induce different transcriptional profiles in dendritic cells following their administration in FVIII-deficient mice. It cannot be excluded that differences in the glycosylation profile between both preparations contributes to this phenomenon. Furthermore, rVWF preparations lack the ABO-determinants learn more that are characteristic of pd-VWF. Given the role of these structures in determining the clearance of VWF, it is of interest to investigate how the non-human glycosylation profile on rVWF affects the survival of this protein in humans. The authors stated that they had no interests which might be perceived as posing a conflict or bias. “
“Discrepancies exist for some of the modified coagulation factors when assayed with different one-stage clotting and chromogenic
substrate assay reagents. The aim of this study was to evaluate the performance of a recombinant factor VIII Fc fusion protein (rFVIIIFc), currently in clinical development for the treatment of severe haemophilia A, in a variety of one-stage clotting and chromogenic selleck inhibitor substrate assays in clinical haemostasis laboratories. Haemophilic plasma samples spiked with rFVIIIFc or Advate® at 0.05, 0.20 or 0.80 IU mL−1 were tested by 30 laboratories using their routine procedures and plasma standards. Data were evaluated for intra- and inter-laboratory
variation, accuracy and possible rFVIIIFc-specific assay discrepancies. For the one-stage assay, mean recovery Reverse transcriptase was 95% to 100% of expected for both Advate® and rFVIIIFc at 0.8 IU mL−1. Intra-laboratory percent coefficient of variance (CV) ranged from 6.3% to 7.8% for Advate®, and 6.0% to 10.3% for rFVIIIFc. Inter-laboratory CV ranged from 10% for Advate® and 16% for rFVIIIFc at 0.8 IU mL−1, to over 30% at 0.05 IU mL−1 for both products. For the chromogenic substrate assay, the average FVIII recovery was 107% ± 5% and 124% ± 8% of label potency across the three concentrations of Advate® and rFVIIIFc, respectively. Plasma rFVIIIFc levels can be monitored by either the one-stage or the chromogenic substrate assay routinely performed in clinical laboratories without the need for a product-specific rFVIIIFc laboratory standard. Accuracy by the one-stage assay was comparable to that of Advate®, while marginally higher results may be observed for rFVIIIFc when using the chromogenic assay.