Premium
The effect of recombinant and plasma‐derived prothrombin on prothrombin time in human plasma
Author(s) -
Hansson K. M.,
Björkqvist J.,
Deinum J.
Publication year - 2015
Publication title -
international journal of laboratory hematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.705
H-Index - 55
eISSN - 1751-553X
pISSN - 1751-5521
DOI - 10.1111/ijlh.12293
Subject(s) - turbidimetry , chemistry , prothrombin time , reagent , chromatography , human plasma , coagulation , medicine
Summary Introduction When investigating coagulation assays to measure the effect of infused prothrombin (FII) in in vivo coagulopathy models, we found that addition of FII, plasma‐derived human FII (pd‐ hFII ) or recombinant human FII (r‐ hFII ), to normal plasma resulted in a concentration‐dependent increase in prothrombin time (PT) initiated with Innovin ® . Methods The effect on PT by addition to plasma of either pd‐ hFII or r‐ hFII , using different commercial PT reagents, was studied both by turbidimetry and viscometry. Result Addition of FII to plasma resulted in increased PT when initiated with Innovin ® : PT increased with 20% by doubling the concentration. The prolongation of PT became more pronounced with 2–6000 times diluted Innovin ® . However, by adjustment of the final free Ca 2+ concentration in the assay with diluted Innovin ® from 8.3 to 1.3 mmol/L, no FII‐dependent increase in PT was found. In contrast, no prolongation of PT was found with other commercial PT reagents. A K M = 3 nmol/L was obtained with pd‐ hFII , respectively, r‐ hFII with FII‐depleted plasma using Thromborel ® to initiate PT. Conclusion At normal plasma concentration of FII , addition of FII should not have an effect on PT . The prolonged PT with Innovin ® , but not with other PT reagents, at supranormal FII concentration is an artefact.