TY - JOUR
T1 - How to interpret and use COVID-19 serology and immunology tests
AU - the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Study Group for Respiratory Viruses (ESGREV)
AU - Ong, David S.Y.
AU - Fragkou, Paraskevi C.
AU - Schweitzer, Valentijn A.
AU - Chemaly, Roy F.
AU - Moschopoulos, Charalampos D.
AU - Skevaki, Chrysanthi
N1 - Publisher Copyright:
© 2021 European Society of Clinical Microbiology and Infectious Diseases
PY - 2021/7
Y1 - 2021/7
N2 - Background: Although molecular tests are considered the reference standard for coronavirus disease 2019 (COVID-19) diagnostics, serological and immunological tests may be useful in specific settings. Objectives: This review summarizes the underlying principles and performance of COVID-19 serological and immunological testing. Sources: Selected peer-reviewed publications on COVID-19 related serology and immunology published between December 2019 and March 2021. Content: Serological tests are highly specific but heterogeneous in their sensitivity for the diagnosis of COVID-19. For certain indications, including delayed disease presentations, serological tests can have added value. The presence of antibodies against SARS-CoV-2 may indicate a recent or past COVID-19 infection. Lateral flow immunoassay (LFIA) antibody tests have the advantages of being easy and fast to perform, but many have a low sensitivity in acute settings. Enzyme-linked immunosorbent assay (ELISA) and chemiluminescence immunoassays (CLIAs) have higher sensitivities. Besides humoral immunity, cellular immunity is also essential for successful host defences against viruses. Enzyme-linked immunospot (ELISpot) assays can be used to measure T-cell responses against SARS-CoV-2. The presence of cross-reactive SARS-CoV-2-specific T cells in never exposed patients suggests the possibility of cellular immunity induced by other circulating coronaviruses. T-cell responses against SARS-CoV-2 have also been detected in recovered COVID-19 patients with no detectable antibodies. Implications: Serological and immunological tests are primarily applied for population-based seroprevalence studies to evaluate the effectiveness of COVID-19 control measures and increase our understanding of the immunology behind COVID-19. Combining molecular diagnostics with serological tests may optimize the detection of COVID-19. As not all infected patients will develop antibodies against SARS-CoV-2, assessment of cellular immunity may provide complementary information on whether a patient has been previously infected with COVID-19. More studies are needed to understand the correlations of these serological and immunological parameters with protective immunity, taking into account the different circulating virus variants.
AB - Background: Although molecular tests are considered the reference standard for coronavirus disease 2019 (COVID-19) diagnostics, serological and immunological tests may be useful in specific settings. Objectives: This review summarizes the underlying principles and performance of COVID-19 serological and immunological testing. Sources: Selected peer-reviewed publications on COVID-19 related serology and immunology published between December 2019 and March 2021. Content: Serological tests are highly specific but heterogeneous in their sensitivity for the diagnosis of COVID-19. For certain indications, including delayed disease presentations, serological tests can have added value. The presence of antibodies against SARS-CoV-2 may indicate a recent or past COVID-19 infection. Lateral flow immunoassay (LFIA) antibody tests have the advantages of being easy and fast to perform, but many have a low sensitivity in acute settings. Enzyme-linked immunosorbent assay (ELISA) and chemiluminescence immunoassays (CLIAs) have higher sensitivities. Besides humoral immunity, cellular immunity is also essential for successful host defences against viruses. Enzyme-linked immunospot (ELISpot) assays can be used to measure T-cell responses against SARS-CoV-2. The presence of cross-reactive SARS-CoV-2-specific T cells in never exposed patients suggests the possibility of cellular immunity induced by other circulating coronaviruses. T-cell responses against SARS-CoV-2 have also been detected in recovered COVID-19 patients with no detectable antibodies. Implications: Serological and immunological tests are primarily applied for population-based seroprevalence studies to evaluate the effectiveness of COVID-19 control measures and increase our understanding of the immunology behind COVID-19. Combining molecular diagnostics with serological tests may optimize the detection of COVID-19. As not all infected patients will develop antibodies against SARS-CoV-2, assessment of cellular immunity may provide complementary information on whether a patient has been previously infected with COVID-19. More studies are needed to understand the correlations of these serological and immunological parameters with protective immunity, taking into account the different circulating virus variants.
KW - Antibodies
KW - COVID-19
KW - Immunity
KW - SARS-CoV-2
KW - Serology
KW - T cell
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U2 - 10.1016/j.cmi.2021.05.001
DO - 10.1016/j.cmi.2021.05.001
M3 - Review article
C2 - 33975005
AN - SCOPUS:85107036432
SN - 1198-743X
VL - 27
SP - 981
EP - 986
JO - Clinical Microbiology and Infection
JF - Clinical Microbiology and Infection
IS - 7
ER -