Different Susceptibility to SARS CoV-2 Infection Among Health Care Workers Highly Exposed to COVID-19. (CoVEX)

Asociacion para el Estudio de las Enfermedades Infecciosas

Status: Completed

Conditions: Immune Response; Health Care Worker Patient Transmission; Susceptibility, Disease; Receptor Site Alteration

Treatments: Diagnostic Test: Susceptibility to infection

Study type: Observational

Funder types: NETWORK

Identifiers

NCT04402827

EC 162/20

Details and patient eligibility

About

The primary objective of this study is to establish differences in susceptibility to SARS CoV-2 infection among health care workers (HCW) highly exposed to patients with COVID-19 diagnosis. To ascertain this issue, we evaluated:

• Changes in receptor polymorphism (ACE2 and CD26 receptor study.
• SARS-CoV-2 CD4/CD8 T cell response (CTL)
• Different KIR phenotypes

Full description

Only 24% of health care workers (HCW) had developed inmunological response to SARS CoV-2 infection in one centre attending thousands of COVID-19 patients, and with shorteness of personal protective equipments. Our hypothesis is that this relatively low number of infected HCW could be secondary to:

1. Differences in susceptibility to infection mediated by changes in viral receptors. Thus, it is important to characterize and genotyping the main receptor for SARS-CoV-2, ACE2, and other related receptor, such as CD26.
2. Increased cellular immune response, offering cross-immunity against SARS CoV-2 infection by previous exposure to other coronavirus or respiratory pathogens. A specific CD4/CD8 T cell response to viral peptides could respond this question
3. Specific KIR phenotypes (Killer Immunoglobulin-like Receptors): Natural killer cells (NK) response to alterations of class I HLA molecules presented in infected cells. An increase in class I HLA expression could lead to an increase in NK activation by increasing its ability to produce IFN-gamma.

Enrollment: 140 patients

Sex: All

Ages: 18 to 65 years old

Volunteers: No Healthy Volunteers

Inclusion and exclusion criteria

Inclusion criteria

• HCW older than 18 years
• Highly exposed to COVID-19 according to the definition
• Negative (cases) or positive (controls) serology against SARS-CoV-2 infection Exclusion criteria
• Presence of any disease / treatment which could alter the susceptibility (corticoid therapy, chemotherapy, monoclonal antibodies)
• Pregnancy

High exposure definition: direct and continued care of COVID-19 diagnosed patients for 2 weeks or more, without aerosol- generating procedures, with inappropriate personal protective equipment (PPE), or unprotected exposure to patients with COVID-19 during aerosol-generating procedures.

The definition of appropriate PPE was based on previous recommendations. The absence of any part of the PPE constituted an unprotected exposure. We defined the following as aerosol-generating procedures: airway suction, application of a high-flow O2 instrument, bronchoscopy, endotracheal intubation, tracheostomy, nebulizer treatment, sputum induction, positive pressure ventilation, manual ventilation and cardiopulmonary resuscitation.

Trial design

140 participants in 2 patient groups

Cases

Description:

HCW highly exposed (defined as more than 15 days of continued personal attention in ICU, anaesthesia, or Infectious Diseases wards) to patients with a diagnosis of COVID-19 (PCR confirmed), who remained asymptomatic and with a negative serology (IgM and IgG negative). Transient entry or stay in the zone (kitchen personnel, rehab members,...) will be not included.

Treatment:

Diagnostic Test: Susceptibility to infection

Controls

Description:

HCW highly exposed to PCR-confirmed patients with a diagnosis of COVID-19, as defined above, matched by age and sex, who had suffered confirmed SARS CoV-2 disease (positive PCR or after, positive IgG)

Treatment:

Diagnostic Test: Susceptibility to infection