Abstract
Reagents previously used for the measurement of the soluble interleukin-2 receptor (IL-2R) required a dedicated analyzer and could not be used for measurements with a general-purpose automatic analyzer. Recently, the general-purpose reagent “Nanopia IL-2R” based on the Latex turbidimetric immunoassay has been developed; thus, its basic performance was investigated. Satisfactory results were obtained in terms of precision, linearity, and sensitivity. No prozone phenomenon was observed, and there was no interference from substances such as free bilirubin, conjugated bilirubin, chyle, and hemoglobin. A strong correlation was observed between Nanopia IL-2R and Detamina CL IL-2R (r = 0.972, y = 0.97x + 8.83). However, there were two cases in which one sample showed falsely high values and one sample with falsely low values caused by a nonspecific reaction. In the former, IgM in serum was considered to be a cause of the falsely high value, because the nonspecific reaction disappeared when the sample was treated with DTT that inactivates IgM. On the other hand, recoveries were examined for the latter. Recoveries of sIL-2R in the sample with falsely low values were low. Therefore, the substances that interfere with sIL-2R measurement using “Nanopia IL-2R” were considered to be present in serum. In summary, our results suggest that the basic performance of the newly developed reagent “Nanopia IL-2R” was satisfactory and had sufficient performance for routine examination. However, caution is required for samples with falsely high or low values.
