Analysis of Commercial Assays for the Detection of SARS-CoV-2 Antibodies or Antigens

Abstract

Background: COVID-19 produced by SARS-CoV-2 infection has spread worldwide. There is a growing need for immunological assays to detect viral specific antibodies or viral antigen. Current standard of diagnosis is reverse-transcriptase polymerase chain reaction (RT-PCR) in nasopharyngeal swabs. However, serological tests can be used to determine previous exposure to the virus and complement the diagnosis. IgM and IgG SARS-CoV-2 specific antibodies can be detected as early as one week after infection and assays can be useful to test large groups of individuals. This work revised the available information concerning assays that detect antibodies and antigens for SARS-CoV-2. Methods: Three sources of information were used: technical data sheets (TDS), web pages of the company’s products, and published articles in Pubmed with reference to the use of diagnostic kits. All the information was revised until April 5th 2020. Results: There were 226 tests coming from 20 countries, mainly from China. TDS were found only in 50 (22.1%). Most assays detect specific antibodies (n 180) based on immunochromatography methods (n 110) and use blood-derived samples (n 105). Assays for antibodies detection measured mainly IgM/IgG (n 112) and the most common procedure time was <20 min (n 83). Internal control referred as sensitivity and specificity was found only in 18.6% (n 42) of the assays. The majority of the tests are currently for in vitro diagnosis (IVD). A total 165 articles were found on PubMed, 15 were included and only 4 used the commercial kits reviewed. Conclusions: Due to the urgency of producing diagnostic tests for SARS-CoV-2, there is a broad offer of kits. Many tests need additional information for their application. The data collected may be useful in the selection of assays, but more and higher quality information is needed.