Long-Term Accuracy of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Interferon-γ Release Assay and Its Application in Household Investigation.
Clin Infect Dis
; 75(1): e314-e321, 2022 08 24.
Article
in English
| MEDLINE | ID: covidwho-2188494
ABSTRACT
BACKGROUND:
An immunodiagnostic assay that sensitively detects a cell-mediated immune response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is needed for epidemiological investigation and for clinical assessment of T- cell-mediated immune response to vaccines, particularly in the context of emerging variants that might escape antibody responses.METHODS:
The performance of a whole blood interferon-gamma (IFN-γ) release assay (IGRA) for the detection of SARS-CoV-2 antigen-specific T cells was evaluated in coronavirus disease 2019 (COVID-19) convalescents tested serially up to 10 months post-infection and in healthy blood donors. SARS-CoV-2 IGRA was applied in contacts of households with index cases. Freshly collected blood in the lithium heparin tube was left unstimulated, stimulated with a SARS-CoV-2 peptide pool, and stimulated with mitogen.RESULTS:
The overall sensitivity and specificity of IGRA were 84.5% (153/181; 95% confidence interval [CI] 79.0-89.0) and 86.6% (123/142; 95% CI 80.0-91.2), respectively. The sensitivity declined from 100% (16/16; 95% CI 80.6-100) at 0.5-month post-infection to 79.5% (31/39; 95% CI 64.4-89.2) at 10 months post-infection (Pâ <â .01). The IFN-γ response remained relatively robust at 10 months post-infection (3.8 vs 1.3 IU/mL, respectively). In 14 households, IGRA showed a positivity rate of 100% (12/12) and 65.2% (15/23), and IgG of 50.0% (6/12) and 43.5% (10/23) in index cases and contacts, respectively, exhibiting a difference ofâ +â 50% (95% CIâ +25.4 to +74.6) andâ +21.7% (95% CI +9.23 to +42.3), respectively. Either IGRA or IgG was positive in 100% (12/12) of index cases and 73.9% (17/23) of contacts.CONCLUSIONS:
The SARS-CoV-2 IGRA is a useful clinical diagnostic tool for assessing cell-mediated immune response to SARS-CoV-2.Keywords
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Main subject:
SARS-CoV-2
/
COVID-19
Type of study:
Diagnostic study
/
Experimental Studies
/
Prognostic study
Topics:
Long Covid
/
Vaccines
/
Variants
Limits:
Humans
Language:
English
Journal:
Clin Infect Dis
Journal subject:
Communicable Diseases
Year:
2022
Document Type:
Article
Affiliation country:
Cid
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