PERFORMANCE CHARACTERISTICS OF SNIBE SARS-COV-2 IgM/IgG AND SARS-COV-2 S-RBD IgG SEROLOGICAL ASSAYS

Abstract

Since corona virus emerged, few tests for diagnosis and follow-up of the disease were approved for urgent use by FDA. Serological tests for the presence of SARS-Cov-2-specific M/G and RBD IgG antibodies manufactured by SNIBE were introduced to the market at the beginning of 2020, with a primary recommendation for monitoring and responding to SARS- Cov-2 infection or vaccines. According to the Standard ISO 15189, each laboratory should take special actions before implementation of any new analyses as routine ones. Bearing this in mind, a verification of the chemiluminescence method for antibody detection according to the CLSI EP 15-A2 and CLSI EP 15-A3 protocol was done in our laboratory. Pooled control samples for IgG, IgM and RBG IgG with two levels, as well as serum samples for positive IgG antibodies were used for method verification. As part of the verification procedure, the precision of the method was estimated. The results of the repeatability and coefficients of variation for SARS-Cov-2 IgM/IgG and SARS-Cov-2 S-RBD IgG were equal or less than the manufacturer’s claims, except for negative control RBD IgG samples. Estimated results for within-laboratory precision (reproducibility) as well as coefficients of variation were less or equal to the manufacturer’s claims, except for positive control samples for IgM. We can conclude that the estimated performance characteristics of SNIBE SARS- Cov-2 IgM/IgG and SARS-Cov-2 S-RBD IgG serological assays are consistent with the manufacturer’s claim’ and that they can be introduced in our laboratory.