Abstract
This study was conducted to evaluate the basic performance of a newly developed squamous cell carcinoma (SCC) assay reagent for the AIA based on fluorescence enzyme immunoassay (FEIA). The reactivity of this reagent with SCC antigens was also evaluated and compared with actual measured values from patients with various diseases. The basic performance of the new reagent was shown to offer good precision and specificity. An evaluation of its correlation with the performance of the reagent used in the ARCHITECT, the conventional assay for SCC, revealed a number of cases with markedly different values. To identify causal factors, the reactivities of the reagents for AIA and ARCHITECT with the recombinant antigens SCCA-1 and SCCA-2 were compared, which showed them to be highly reactive with SCCA-2 and SCCA-1, respectively, suggesting that this difference in reactivity may be a cause of the markedly different values. We also encountered another case of a benign disease with deviating elevated values obtained using the ARCHITECT, in which polymerized SCC antigens resulting from the binding of IgG and SCC antigens in the blood were thought to be associated with the falsely elevated values determined using the ARCHITECT. Other evaluations revealed a high positivity rate for SCC and positivity rates equivalent to those obtained using the ARCHITECT for various other diseases. This study shows that the new SCC assay reagent for the AIA, which offers good precision and specificity and allows measurements to be taken in approximately 20 min, appears to be highly useful in routine laboratory tests, particularly those performed prior to clinical consultation.
