NCT04703114

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

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

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 57 (actual)
• Sponsor: Assistance Publique - Hôpitaux de Paris · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

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

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.

Conditions

• Covid19
• SARS-CoV-2

Interventions

Type	Name	Description
DIAGNOSTIC_TEST	Blood count	Blood count at each visit
DIAGNOSTIC_TEST	Blood collection	Blood collection to understanding of the immunological profile at each visit
DIAGNOSTIC_TEST	Nasopharyngeal swab	Research of SARS-CoV-2 infection in nasopharyngeal swab by RT-PCR at day 8 and day 15
DIAGNOSTIC_TEST	Saliva samples	Research of SARS-CoV-2 infection in saliva samples at each visit (excepted inclusion)
DIAGNOSTIC_TEST	Faeces samples	Research of SARS-CoV-2 infection in faeces samples at day 3, day 15 and day 90
GENETIC	Genetic blood collection	Collection to further research at each visit
OTHER	Data collection	Demographics, symptoms, biological constants

Timeline

• Start date: 2021-02-05
• Primary completion: 2021-09-15
• Completion: 2021-09-15
• First posted: 2021-01-11
• Last updated: 2026-03-27

Locations

1 site across 1 country: France