The limitations in the originally devised assay for activated protein C resistance led to the development of a modified assay.
Other variations of the activated protein C resistance assay have been developed.
For the first 6 months of life, the reference range for the original assay for activated protein C resistance was found to be higher than in individuals older than 6 months.
Factor V--deficient plasma contains normal factor VIII molecules and, therefore, its use will mask any mutation in the patient's factor VIII that allows it to resist degradation by activated protein C.
One method of reporting a result for activated protein C resistance involves the use of a normalized ratio.
The original assay, despite its limitations, is undergoing evaluation to determine whether the numerical test result for activated protein C resistance provides information regarding hypercoagulability in the absence of factor V Leiden by a DNA-based method.
Diagnostic Algorithm for Assessment of Activated Protein C Resistance and Factor V Leiden
In the Recombinant Human Activated Protein C Worldwide Evaluation in Severe Sepsis (PROWESS) study, the incidence of bleeding with drotrecogin alfa (activated) was 3.
Because this product is a recombinant form of a human protein, antibodies to activated protein C may develop.
In a phase II trial designed to assess the safety and utility of recombinant human activated protein C, 131 patients were randomized to receive placebo (n = 41) or 1 of 4 doses of drotrecogin alfa (activated) for 48 or 96 hours (12).
They also concluded that recombinant human activated protein C produced a dose-dependent improvement in markers of inflammation and coagulation commonly associated with severe sepsis and produced a trend towards decreased mortality (12).
Drotrecogin alfa (activated) is a recombinant form of human activated protein C.
Efficacy and safety of recombinant human activated protein C for severe sepsis.