2019 Volume 68 Issue 3 Pages 476-480
We analyzed the cause of nonspecific reactions of the reagent “Determiner CL IL-2R NX” for the measurement of the soluble interleukin-2 receptor. Furthermore, the basic performance of this improved reagent and its inhibitory effect on nonspecific reactions were investigated. The improved reagent was added to suppress the causative agent. As a result of the analysis of the cause of nonspecific reactions using the improved reagent that was added to suppress alkaline phosphatase (ALP), fibrin and HAMA, it was revealed that ALP participated in nonspecific reactions. We performed a dilution analysis of a sample for nonspecific reactions. The sIL-2R value of the undiluted sample analyzed using the currently used reagent was 42,946 U/mL, but it decreased and became 1,904 U/mL after 8-fold dilution. On the other hand, the sIL-2R value obtained using the improved reagent was similar to those of the diluted and undiluted samples. We measured the sIL-2R value of nonspecific samples using the improved reagent that changed the concentration of ALP, which was a causative agent of nonspecific reactions, to examine the suppression of such reactions. As a result, the nonspecific reactions were inhibited by tenfold those of a currently used reagent. Satisfactory precision, accuracy, and linearity were obtained with the improved reagent. In summary, our results suggest that the improved reagent “Determiner CL IL-2R NX” showed sufficient performance for routine examinations and its basic performance is equal to that of the currently used reagent. Moreover, the nonspecific reactions with ALP were inhibited. However, it was considered that further examinations using different samples are necessary because we were able to analyze only one nonspecific sample in this work.
