ABSTRACT
A high volume of diagnostic tests is needed during the coronavirus disease 2019 (COVID-19) pandemic to obtain representative results. These results can help to design and implement effective policies to prevent the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Diagnosis using current gold standard methods, i.e., real-time quantitative PCR (RT-qPCR), is challenging, especially in areas with limited trained personnel and health-related infrastructure. The toehold switch-based diagnostic system is a promising alternative method for detecting SARS-CoV-2 that has advantages such as inexpensive cost per testing, rapid, and highly sensitive and specific analysis. Moreover, the system can be applied to paper-based platforms, simplifying the distribution and utilization in low-resource settings. This review provides insight into the development of toehold switch-based diagnostic devices as the most recent methods for detecting SARS-CoV-2.
ABSTRACT
BACKGROUND: Coronavirus disease 2019 (COVID-19) is a global health problem that causes millions of deaths worldwide. The clinical manifestation of COVID-19 widely varies from asymptomatic infection to severe pneumonia and systemic inflammatory disease. It is thought that host genetic variability may affect the host's response to the virus infection and thus cause severity of the disease. The SARS-CoV-2 virus requires interaction with its receptor complex in the host cells before infection. The transmembrane protease serine 2 (TMPRSS2) has been identified as one of the key molecules involved in SARS-CoV-2 virus receptor binding and cell invasion. Therefore, in this study, we investigated the correlation between a genetic variant within the human TMPRSS2 gene and COVID-19 severity and viral load. RESULTS: We genotyped 95 patients with COVID-19 hospitalised in Dr Soetomo General Hospital and Indrapura Field Hospital (Surabaya, Indonesia) for the TMPRSS2 p.Val160Met polymorphism. Polymorphism was detected using a TaqMan assay. We then analysed the association between the presence of the genetic variant and disease severity and viral load. We did not observe any correlation between the presence of TMPRSS2 genetic variant and the severity of the disease. However, we identified a significant association between the p.Val160Met polymorphism and the SARS-CoV-2 viral load, as estimated by the Ct value of the diagnostic nucleic acid amplification test. Furthermore, we observed a trend of association between the presence of the C allele and the mortality rate in patients with severe COVID-19. CONCLUSION: Our data indicate a possible association between TMPRSS2 p.Val160Met polymorphism and SARS-CoV-2 infectivity and the outcome of COVID-19.