2026 Volume 75 Issue 2 Pages 320-327
The basic performance of the newly developed TP antibody measurement reagent ‘TPAb-Latex ‘SEIKEN’’ was evaluated and compared with four pre-existing reagents. The basic performance of ‘SEIKEN’ demonstrated the following favorable outcomes: the precision exhibited a coefficient of variation (CV) of less than 3% within the concentration range pertinent to positive decision-making; the measurement range extended from 5 to 500 U/mL; the prozone check functioned effectively; and there was no interference from coexisting substances. The overall percentage agreement with the three pre-existing reagents, which were based on the latex agglutination turbidimetric assay, was Reagent A 97.0%, Reagent B 95.8%, and Reagent C 92.8%, respectively. Immunoblotting identified the presence of IgG and/or IgM in all samples deemed positive by ‘SEIKEN’ (5 specimens) among the 18 specimens that exhibited discordant results with the reference reagents. Consequently, the disagreement is unlikely to be attributed to false positives resulting from non-specific reactions of ‘SEIKEN’. Furthermore, the specimen tested positive exclusively with the ‘SEIKEN’, which identified the presence of IgM (TpN17). The ‘SEIKEN’ successfully detected TP antibodies in the seroconversion panel in agreement with immunoblotting on day 31, marking the earliest detection among the reagents tested. This indicates that the ‘TPAb-Latex ‘SEIKEN’’ exhibits high reactivity to TpN17-IgM and potentially possesses enhanced sensitivity during the early stages of infection.
