Clinical evaluation of the ELISPOT method: A new test for COVID-19 using blood

Kobe University and Sysmex Corporation have been engaged in joint research on the ELISPOT method, a new blood test for identifying the novel coronavirus disease (COVID-19). This method makes it possible to detect the immune response of T cells to the novel coronavirus (SARS-CoV-2). Here we provide an overview of the method and the results of the clinical evaluation. This information will also be made available through conference presentations and by paper submission.

Although SARS-CoV-2 is highly infectious and may rapidly develop into a severe condition, many carriers of the virus are asymptomatic. To address this situation, research has been carried out to develop ways in which vaccine efficacy and safety can be assessed, in addition to the tests conducted in the period shortly after SARS-CoV-2 infection through to the treatment / recovery phase. "T-SPOT Discovery SARS-CoV-2" (hereinafter referred to as the "kit"), the research reagent kit developed by Oxford Immunotec Ltd. (HQ: Oxford, the United Kingdom), measures the number of T cells that secrete interferon (IFN) -γ by stimulating an infected SARS-CoV-2 specific antigen and can confirm past exposure to SARS-CoV-2 and latent infection. It will also enable research on immune monitoring and the strength of the immune response to COVID-19 (Figure 1).

Recently, the research group from Kobe University Hospital BioResource Center (Location: Kobe, Japan; Director: Hiroshi Matsuoka) and Sysmex used this kit to examine blood samples collected from 10 uninfected Japanese subjects and 15 Japanese subjects who had recovered from COVID-19. The results obtained so far show enhanced T cell immune responses in all individuals who recovered from COVID-19, while no enhanced T cell immune responses were found in uninfected individuals. This result suggests that the kit can be used to evaluate T cell immune response to SARS-CoV-2 in the Japanese population as well. It could also be utilized to complement PCR tests to measure gene expression, and antibody / antigen tests to measure the characteristics of proteins (Figure 2 and 3).

This kit has been selected by the Vaccines Taskforce established by the British government1 and is used to evaluate vaccines' activation of immune functions. It may also provide important findings that will aid the development of future treatment strategies.

Sysmex and Kobe University will conduct further joint research at the molecular and cellular levels. Both parties will continue to contribute towards the diagnosis and treatment of COVID-19 by disclosing further details regarding T cell immunity and expeditiously establishing a test method suitable for clinical use.

Provided by Kobe University