Antigen tests detect proteins

Antigen tests detect proteins. reported to have poor sensitivity in comparison with PCR [34,35]. However, in 2020, the opinion was divided on the usefulness of antigen tests. There were many negative reports. Mouse monoclonal to HK1 Scohy pointed out that a rapid immuno-chromatographic test for the detection of SARS-CoV-2 antigen provided the poor sensitivity (30.2%) compared with gold standard PCR, suggesting that it should not be used alone as the frontline testing for COVID-19 diagnosis [36]. Mak also indicated that a rapid immuno-chromatographic antigen test was 105-fold less detection-sensitive than PCR for SARS-CoV-2, and it detected only between 11.1% and 45.7% of PCR-positive samples obtained from COVID-19 patients [37]. They concluded that a rapid antigen test can serve only as an adjunct to the PCR test. On the other hand, there are some papers insisting that rapid antigen tests should be used for the first-line diagnosis of COVID-19. Mertens and colleagues used an immunochromatographic assay for DTP348 the rapid detection of SARS-CoV-2 antigen and found 57.6% sensitivity and 99.5% specificity, with an accuracy of 82.6% [38]. Even though the sensitivity appeared low, the specificity was high enough, and the detection time was only 15 min. Thus, they suggested that the antigen tests are complementary to the PCR. There was another report to recommend the use of antigen tests in the diagnosis of SARS-CoV-2 infection to control the spread of infection [26]. Various other reports regarding the performance of the commercially available rapid antigen tests have been published from Germany [39], India [40], Italy [41], Spain [42,43], Thailand [44], and USA [45]. All these results indicated that the sensitivity was decent (70.6%C100%) and the specificity was high DTP348 (96%C100%). The results from a meta-analysis of published papers showed that the average sensitivity was 56.2% (95% CI: 29.5% to 79.8%), and the average specificity was 99.5% (95% CI: 98.1% to 99.9%) [25]. That is, the high specificity of antigen tests for COVID-19 was remarkable. From the viewpoint of the emergency use listing procedure (EUL) by the WHO [46], we could find the 2 2 antigen tests: Panbio COVID-19 Ag Rapid Test by Abbott Rapid Diagnostics and STANDARD Q COVID-19 Ag Test by SD BIOSENSOR [47,48]. Some papers reported that the sensitivity was not so high for these antigen tests even though they were a little better than the tests that were not listed on EUL [49C51]. As can be seen, the antigen tests generally had low sensitivity and high specificity. Regarding the problem of specificity, we noted two papers on a commercially available DTP348 antigen test in Japan [52]. One is the paper reported by Hirotsu and colleagues, describing that, in comparison with the PCR results, the antigen test based on chemiluminescence enzyme immunoassay exhibited 55.2% sensitivity and 99.6% specificity, with a 91.4% overall agreement rate [53]. They concluded that this antigen test may be helpful for monitoring viral clearance in hospitalized patients, because the specificity was so high (i.e., 99.6%). In other words, the false-positive results seemed very rare. However, the other paper reported by Ogawa excited attention that this antigen test may offer some false-positive results [54]. The Ministry of Health, Labour, and Welfare of Japan enables the definitive analysis of COVID-19 without PCR when the antigen test shows positive [55]. Consequently, Ogawa warned that the use of antigen checks in Japan, which are prone to false positive, may create a situation in which false-positive individuals who are not infected with SARS-CoV-2 are at risk of nosocomial illness [54]. That is, the use of antigen checks is dangerous for admission into a hospital. Recently, new techniques have been utilized for antigen checks of SARS-CoV-2. A study using a fluorescence immunochromatographic antigen test for SARS-CoV-2 showed 93.9% sensitivity and 100% specificity for the patients who displayed the symptoms within a week [56]. The authors suggested that this antigen test will become an important tool in situations with limited access to molecular methods. Another study using a fluorescence immuno-chromatographic assay also offered good data concerning both the level of sensitivity and specificity [57]. This showed the level of sensitivity was 75.6%, and the specificity was 100%. These results suggest that fluorescence immunochromato-graphic antigen checks are potentially useful for COVID-19 analysis in the early phases of illness. In addition, there is a quick detection system achieved by an integration of nanozyme and enzymatic.