The prothrombin time assay, in conjunction with rivaroxaban calibrators, showed reduced interlaboratory variation when expressed as concentrations and may be useful for measuring peak plasma levels.
Does the prothrombin time assay with rivaroxaban calibrators provide precise measurement of rivaroxaban plasma concentrations across different laboratories?
The widely available PT assay, when used in conjunction with rivaroxaban calibrators, may be useful for the measurement of peak plasma levels of rivaroxaban.
This study evaluated the prothrombin time (PT) assay for the measurement of plasma concentrations of rivaroxaban using calibrators and controls. The intra- and interlaboratory precision of the measurement was investigated in a field trial involving 21 laboratories. Each laboratory was provided with rivaroxaban calibrators and control plasma samples containing different concentrations of rivaroxaban, and PT reagents. The evaluation was carried out over 2 consecutive weeks using centrally provided and local PT reagents. A calibration curve was produced each day (for inter-run precision), and day-to-day precision was evaluated by testing 3 control plasma samples. A large interlaboratory variation (in seconds) was observed with local PT reagents. The results were less variable when expressed as rivaroxaban concentrations (ng/mL) or when central PT reagent was used (STA Neoplastine CI Plus). The widely available PT assay, in conjunction with rivaroxaban calibrators, may be useful for the measurement of peak plasma levels of rivaroxaban.
Samama et al. (Fri,) reported a other. Prothrombin time (PT) assay with rivaroxaban calibrators vs. Local PT reagents was evaluated on Intra- and interlaboratory precision of rivaroxaban plasma concentration measurement. The prothrombin time assay, in conjunction with rivaroxaban calibrators, showed reduced interlaboratory variation when expressed as concentrations and may be useful for measuring peak plasma levels.