New BRP for human plasma calibrated for coagulation factors V, VIII, XI and XIII - collaborative study for establishment of batches 1 and 2.

A human plasma reference preparation in International Units (IU) must be used in each potency assay of the human coagulation factors V, VIII and XI in human plasma pooled and treated for virus inactivation, according to the European Pharmacopoeia (Ph. Eur.) monograph 1646 and general chapters 2.7.4 and 2.7.22 respectively, and in the potency assay of human coagulation factor XIII in fibrin sealant kits, according to Ph. Eur. monograph 0903. International reference standards for all of these factors are now established, however, regional reference standards were not available for the required routine use. It was therefore proposed by European OMCLs and manufacturers to establish a European reference preparation, and it was the goal of this study to accomplish that. Two candidate biological reference preparations (BRPs), separate lyophilisation lots of the same normal human plasma bulk material, were calibrated against the International Standards (ISs) for human coagulation factors V, VIII, XI and XIII. Twelve European laboratories including OMCLs and manufacturers participated. The candidate material was tested against the ISs in 4 separate assays for each factor using the methods described in the relevant Ph. Eur. monographs and general chapters. No discernable difference was noted between the activities of the 2 candidates. They were shown to be suitable for their intended use and it was recommended to assign to both batches a potency of 0.73 IU/mL for factor V, 0.74 IU/mL for factor VIII, 0.59 IU/mL for factor XI and 0.79 IU/mL for factor XIII. Candidate batch B is proposed to be used first as lot 1, followed upon its depletion by candidate batch A (lot 2). The BRP batches will be monitored regularly for potency throughout their lifetime. EDQM BRP batches 1 and 2 of coagulation factors V, VIII, XI and XIII plasma were formally adopted by the Ph. Eur. Commission at their session in June 2011.