Evaluation of the basic performance of (N-type) Nanopia IL-2R and its inhibitory effect on non-specific reactions

Abstract

Soluble interleukin-2 receptor (sIL-2R) is significantly elevated in patients with non-Hodgkin lymphoma and adult T-cell leukemia/lymphoma (ATL), making it an outstanding serum biomarker of these diseases. While chemiluminescent enzyme immunoassay (CLEIA), enzyme-linked immunosorbent assay (ELISA), and latex turbidimetric immunoassay (LTIA) are routine assays for sIL-2R, non-specific reactions are reportedly more common in LTIA than in CLEIA and ELISA. In the present study, we evaluated (N-type) Nanopia IL-2R—a recently-marketed improved LTIA reagent developed by SEKISUI MEDICAL CO., LTD. to inhibit non-specific reactions—in order to determine its basic performance and its inhibitory effect on non-specific reactions. For the control reagents, we used the conventional LTIA reagent and a CLEIA reagent. The results showed that the improved LTIA reagent had satisfactory basic performance, and that the correlation between serum sIL-2R values determined by CLEIA and those determined by LTIA was higher for the improved LTIA reagent than for the conventional LTIA reagent. In the immunoglobulin absorption test using samples from discrepant cases, the improved LTIA reagent demonstrated a suppressive effect on non-specific reactions mainly caused by IgG. The results of the present study demonstrated that the improved reagent performs sufficiently when used in routine LTIA of serum sIL-2R values. The results also suggest that compared to the conventional LTIA reagent, the improved LTIA reagent strongly inhibits non-specific reactions with immunoglobulin—particularly IgG—in serum samples.