Manuscript Detail

Title: Different Innate and Adaptive Immune Responses to SARS-CoV-2 Infection of Asymptomatic, Mild, and Severe Cases

Authors: Carsetti, Rita et al

Abstract: SARS-CoV-2 is a novel coronavirus, not encountered before by humans. The wide spectrum of clinical expression of SARS-CoV-2 illness suggests that individual immune responses to SARS-CoV-2 play a crucial role in determining the clinical course after first infection. Immunological studies have focused on patients with moderate to severe disease, demonstrating excessive inflammation in tissues and organ damage. In order to understand the basis of the protective immune response in COVID-19, we performed a longitudinal follow-up, flow-cytometric and serological analysis of innate and adaptive immunity in 64 adults with a spectrum of clinical presentations: 28 healthy SARS-CoV-2-negative contacts of COVID-19 cases; 20 asymptomatic SARS-CoV-2-infected cases; eight patients with Mild COVID-19 disease and eight cases of Severe COVID-19 disease. Our data show that high frequency of NK cells and early and transient increase of specific IgA, IgM and, to a lower extent, IgG are associated with asymptomatic SARS-CoV-2 infection. By contrast, monocyte expansion and high and persistent levels of IgA and IgG, produced relatively late in the course of the infection, characterize severe disease. Modest increase of monocytes and different kinetics of antibodies are detected in mild COVID-19. The importance of innate NK cells and the short-lived antibody response of asymptomatic individuals and patients with mild disease suggest that only severe COVID-19 may result in protective memory established by the adaptive immune response.

Journal: Front Immunol

Curator: Hancock Lab

Reviewer: Aris Floratos

Author-provided data:

paper: Carsetti, R., Zaffina, S., Piano M. E., Terreri, S., Corrente, F., Capponi, C., Palomba, P., Mirabella, M., Cascioli, S., Palange, P., Cuccaro, I., Milito, C., Zumla, A., Maeurer, M., Camisa, V., Vinci, M. R., Santoro, A., Cimini, E., Marchioni, L., Nicastri, E., Palmieri, F., Agrati, C., Ippolito, G., Porzio, O., Concato, C., Onetti M. A., Raponi, M., Quintarelli, C., Quinti, I. and Locatelli, F. (2020). Different Innate and Adaptive Immune Responses to SARS-CoV-2 Infection of Asymptomatic, Mild, and Severe Cases. Front Immunol https://www.ncbi.nlm.nih.gov/pubmed/33391280/
contributor: Rita Carsetti
contributor_organization: Bambino Gesù Children’s Hospital
contributor_email: rita.carsetti@opbg.net

- description: NK cells were reduced and monocytes increased in patients with severe COVID-19. We show that the ratio between NK cells and monocytes was <1 in asymptomatic individuals, >1 in patients with mild disease and even higher in severe cases.
- exact_source: Figure 1C D and E
- tissue: PBMC
- immune_exposure: COVID-19 infection
- cohort: 20 asymptomatic SARS-CoV-2-infected cases; 8 patients with Mild COVID-19 disease; 8 cases of Severe COVID-19 disease.
- comparison: asymptomatic vs mild vs severe from the first positive swab
- repository_id: not applicable
- platform: not applicable
- response_components:
- response_behavior:
  - - description: Severe patients have the highest levels of IgG and IgA. Our most interesting observation is the different kinetics of response in asymptomatic and mild disease forms of infection. The early and transient IgM, IgA, and IgG responses distinguish asymptomatic individuals from mild-disease patients, who have a slower, but more persistent antibody production.
    - exact_source: Figure 6
    - tissue: Serum
    - immune_exposure: COVID-19 infection
    - cohort: 20 asymptomatic SARS-CoV-2-infected cases; 8 patients with Mild COVID-19 disease; 8 cases of Severe COVID-19 disease.
    - comparison: asymptomatic vs mild vs severe from the first positive swab
    - repository_id: not applicable
    - platform: not applicable
    - response_components:
    - response_behavior:

Spreadsheet: Link to curation spreadsheet