Closing the serological gap in the diagnostic testing for COVID-19: The value of anti-SARS-CoV-2 IgA antibodies.
J Med Virol
; 93(3): 1436-1442, 2021 03.
Article
en En
| MEDLINE
| ID: mdl-32790181
ABSTRACT
During coronavirus disease 2019 (COVID-19) pandemic, the early diagnosis of patients is a priority. Serological assays, in particular immunoglobulin (Ig)M and IgG anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), have today several applications but the interpretation of their results remains an open challenge. Given the emerging role of the IgA isotype in the COVID-19 diagnostics, we aimed to identify the SARS-CoV-2 IgA antibodies in a COVID-19 population seronegative for IgM. A total of 30 patients hospitalized in San Giovanni di Dio Hospital (Florence, Italy) for COVID-19, seronegative for IgM antibodies, have been studied for anti-SARS-CoV-2 antibodies. They all had a positive oro/nasopharyngeal swab reverse transcription-polymerase chain reaction result. Assays used were a chemiluminescent assay measuring SARS-CoV-2 specific IgM and IgG (S + N) and an ELISA, measuring specific IgG (S1) and IgA antibodies against SARS-CoV-2. Among the 30 patients, eight were positive for IgA, seven were positive for IgG (N + S), and two for IgG (S1), at the first point (5-7 days from the onset of symptoms). The IgA antibodies mean values at the second (9-13 days) and third (21-25 days) time points were even more than twice as high as IgG assays. The agreement between the two IgG assays was moderate (Cohen's K = 0.59; SE = 0.13). The inclusion of the IgA antibodies determination among serological tests of the COVID-19 diagnostic is recommended. IgA antibodies may help to close the serological gap of the COVID-19. Variations among anti-SARS-CoV-2 IgG assays should be considered in the interpretation of results.
Palabras clave
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Inmunoglobulina A
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Prueba Serológica para COVID-19
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SARS-CoV-2
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COVID-19
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Anticuerpos Antivirales
Tipo de estudio:
Diagnostic_studies
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Prognostic_studies
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Screening_studies
Límite:
Adult
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Aged
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Revista:
J Med Virol
Año:
2021
Tipo del documento:
Article
País de afiliación:
Italia