Study of the Immunological and Virological Response of Patients With COVID-19 and Presenting an Asymptomatic or Pauci-symptomatic Form (AMBUCOV)

Study Overview
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Brief Summary
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The purpose of this study is to describe the immunological and virological response of patients infected with CoV-2-SARS and presenting an asymptomatic or mildly symptomatic form, in particular the innate and adaptive response as well as the virological clearance kinetics. The research hypothesis is that patients with an ambulatory form of SARS-CoV-2 infection, whether asymptomatic or mildly symptomatic, are able to mount an innate and adaptive immunological response capable of rapidly clearing the virus, in contrast to severe forms in which an early deficit of type 1 IFN response has been demonstrated, possibly responsible for a defect in the control of viral replication in the blood.

Detailed Description
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A new coronavirus (SARS-CoV-2) was identified in December 2019 in the Wuhan region of China and is currently causing a global pandemic. The disease, named COVID-19, causes an influenza syndrome associated with respiratory signs, but there are also asymptomatic and pauci-symptomatic forms. Approximately 2 to 3% of patients, primarily patients with pre-existing chronic diseases and the elderly, develop a very severe form responsible for an acute respiratory distress syndrome (ARDS) that can lead to death. It has been shown that patients with a severe and critical form had an impaired type 1 interferon response, with decreased plasma levels of IFN-alpha2 in the most severe patients compared to hospitalized patients with a moderate form, and undetectable levels of IFN-beta. This lack of type 1 IFN response was associated with greater viral persistence in the blood and an exaggerated inflammatory response mediated primarily by the NF-kB pathway. Almost all studies published to date on immune system disruption during CoV-2-SARS infection included mainly hospitalized patients requiring oxygen therapy due to their severity, assessed at the time of clinical worsening. Thus, there is no or little data on immunological response profiles, particularly on type 1 IFN response but also on other aspects of the immunological response (adaptive cellular and humoral immunity), and its relationship with viral clearance kinetics during ambulatory forms of SARS-CoV-2 infection, whereas these forms represent more than 95% of the clinical forms. The asymptomatic and pauci-symptomatic forms managed on an outpatient basis represent the most common form of CoV-2-SARS infection, with a favourable outcome in almost all cases. A better description and understanding of the immunological profile, including type 1 IFN response and viral clearance kinetics in saliva, blood and feces, during asymptomatic and mild clinical forms will allow the identification of the major players in the immune response against SARS-CoV-2, and thus better define the responses that are lacking in severe patients.

Official Title
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Study of the Immunological and Virological Response of Patients Infected With SARS-CoV-2 and Presenting an Asymptomatic or Pauci-symptomatic Form

Conditions
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Covid19, SARS-CoV-2

Intervention / Treatment
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* Diagnostic Test: Blood count
* Diagnostic Test: Blood collection
* Diagnostic Test: Nasopharyngeal swab
* Diagnostic Test: Saliva samples
* Diagnostic Test: Faeces samples
* Genetic: Genetic blood collection
* Other: Data collection


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult patients Nasopharyngeal PCR positive for SARS-CoV-2 within 48 hours prior to inclusion in the study protocol, carried out in one of the participating outpatient screening centers Symptomatic patients (nasopharyngeal screening positive due to suggestive symptoms) or asymptomatic (nasopharyngeal screening positive due to screening after contact with a positive subject) Patients who have been informed and signed the consent Pregnant and breastfeeding women who may be included in the study. Exclusion Criteria: Patients with criteria for hospitalization at the time of diagnosis (seriousness criteria, impossibility of staying at home) Non-consent or inability to obtain consent, Patient with dementia or not authorized, for psychiatric reasons or intellectual failure, to receive information on the protocol and to give informed consent, Patient under guardianship / curatorship

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Symptomatic<br>40 symptomatic patients to COVID-19 infection | Diagnostic Test: Blood count<br>* Blood count at each visit<br>Diagnostic Test: Blood collection<br>* Blood collection to understanding of the immunological profile at each visit<br>Diagnostic Test: Nasopharyngeal swab<br>* Research of SARS-CoV-2 infection in nasopharyngeal swab by RT-PCR at day 8 and day 15<br>Diagnostic Test: Saliva samples<br>* Research of SARS-CoV-2 infection in saliva samples at each visit (excepted inclusion)<br>Diagnostic Test: Faeces samples<br>* Research of SARS-CoV-2 infection in faeces samples at day 3, day 15 and day 90<br>Genetic: Genetic blood collection<br>* Collection to further research at each visit<br>Other: Data collection<br>* Demographics, symptoms, biological constants<br>|
| Experimental: Asymptomatic<br>40 asymptomatic patients to COVID-19 infection | Diagnostic Test: Blood count<br>* Blood count at each visit<br>Diagnostic Test: Blood collection<br>* Blood collection to understanding of the immunological profile at each visit<br>Diagnostic Test: Nasopharyngeal swab<br>* Research of SARS-CoV-2 infection in nasopharyngeal swab by RT-PCR at day 8 and day 15<br>Diagnostic Test: Saliva samples<br>* Research of SARS-CoV-2 infection in saliva samples at each visit (excepted inclusion)<br>Diagnostic Test: Faeces samples<br>* Research of SARS-CoV-2 infection in faeces samples at day 3, day 15 and day 90<br>Genetic: Genetic blood collection<br>* Collection to further research at each visit<br>Other: Data collection<br>* Demographics, symptoms, biological constants<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Interferon response | Concentration of type I, type II and type III Interferon in peripheral blood | Up to 90 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Immunology : cytokines | Concentration of IL-6, TNF-alpha, IL-8, calprotectin in peripheral blood | Up to 90 days | 
| Immunology : cell population | Proportions of monocytes, B cells and T cells in peripheral blood | Up to 90 days | 
| Immunology : proteins | Concentration of anaphylatoxins C3a and C5a in peripheral blood | Up to 90 days | 
| Immunology : pathways | Screening for genetic mutations involved in the interferon pathway | Up to 90 days | 
| Immunology : antibody response | Concentration of antibodies directed against spike protein and nucleocapsids | Up to 90 days | 
| Virology : Nasopharyngeal Viral clearance kinetics | Viral clearance kinetics in nasopharyngeal samples | Up to 90 days | 
| Virology : Saliva Viral clearance kinetics | Viral clearance kinetics in saliva | Up to 90 days | 
| Virology : faeces viral clearance kinetics | Viral clearance kinetics in faeces | Up to 90 days | 
| Virology : peripheral blood viral clearance kinetics | Viral clearance kinetics in peripheral blood | Up to 90 days | 
| Virology : sequencing | Analysis of virus mutations, especially of the gene encoding spike protein | Up to 90 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Covid19, SARS-CoV-2, Immunology