Basic performance evaluation of a liquid-type prothrombin time kit “HemosIL ReadiPlasTin”

Abstract

In the past, most prothrombin time (PT) reagents were required to add special dissolving solution or purified water. Recently, several companies have released liquid-type PT kits that are easy to prepare. This time, we report on the basic performance evaluation of a liquid-type PT kit, “HemosIL ReadiPlasTin” (I.L.Japan Co., Ltd.), using ACL TOP 550 CTS (I.L.Japan Co., Ltd). Two concentrations of control plasma and post-test residual patient plasma were used as samples. The repeatability was less than 1.5% CV after 10 times measurements, and the onboard stability was less than 3.0% CV after 14 days of measurements twice a day. The dilution linearity was confirmed up to 144.3% for PT activity and the limit of detection was 5.7%. The effect of comorbidities was less than 5% change in each case. The effect of heparin was less than 10% up to 1.25 U/mL. The correlation with the conventional reagent was y = 0.987x − 0.0138, r = 0.9978 for PT-INR. The preparation time was less than 1 minute for the study reagent, whereas the conventional reagent was about 34 minutes. The basic performance of the HemosIL ReadiPlasTin was very good and correlated well with the conventional reagent. The conventional reagent was taken more than 30 minutes to prepare, and there was a risk of solvent dispensing errors, whereas the study reagent could be used immediately by simply mixing two liquid vials, which was considered to have very high usability and significantly reduce the burden on medical technologist.