Antibodies Responses to COVID-19 Infection in Hospitalized Patients

Summary

1.5. Why this clinical study?

The prevalence of seropositivity following SARS-CoV 2 infection might have its own potential benefits in terms of predicting the end of pandemic and the validity of herd immunity. It is not clear if SARS-CoV 2 infection would have a long-lasting antibody-mediated immunity, and if the antibodies' persistence is dependent on disease severity.depends on the severity of illness. If evidence is provided about the persistence of antibodies that is reflective of the protective immune response, serodiagnosis will be an important tool to identify individuals with various risk for infection, and those who are in need of receiving the forthcoming vaccines.

The here proposed prospective clinical study will test the prevalence of seropositivity following SARS-CoV 2 infection in critically ill patients compared to those who do not require intensive care unit (ICU) admission or invasive ventilation with respect to the IgM and IgG levels.

Conditions

• Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV 2 Infection)
• Hospitalized Patients
• Laboratory-confirmed SARS-CoV 2 Infection

Interventions

DIAGNOSTIC_TEST

Testing procedure for Binding antibodies

Levels of S-specific and N-specific binding antibodies will be measured by enzyme immune-sorbent assay (ELISA). Briefly, a purified, recombinant S or N proteins will be coated into 96-well plates and incubated for 1 hour at room temperature. The plates will be then washed with 1X PBS five times. The unbound regions of the coated S proteins are blocked by 5% non-fat dry milk. After overnight incubation at 4 C. The plates are washed several times with 5X PBS. Patients sera samples are added in duplicate and incubated for 1 hour at room temperature. After several washes. anti-human IgG HRP conjugate is added. After 1-hour incubation at room temperature, the plates are washed with 1X PBS five times 3,3', 5,5' tetramethylbenzidine (TMB) substrate is added to each wells and incubated for 5 minutes. The reaction will be then stopped with 0.2 M sulfuric acid and the absorbance is measured at 450nm.

DIAGNOSTIC_TEST

Neutralizing antibodies

Neutralizing antibodies against the S protein of SARS-CoV-2 are measured by PV microneutralization assay. Briefly, individual plasmids expressing S.fl gene, luciferase genes, and reporter genes are co-transfected into 293T cells to produce luciferase-expressing pseudo-viruses. Then, pseudo-viruses are added at equal volume into 96 well plates and incubated at 37 for 1 hour. Then, the ACE2 expressing 293T cells are added into the 96well pates with 100 ul of patients' sera in duplicates. After, a single round of replication the cells are lysed with lysis buffer. Luciferase activity is measured by the luciferase assay kit. The activity of luciferases is proportional to the number of cells infected. Luciferase activity is then measured by the luminometer device and the neutralization rate is calculated.

Sponsors & Collaborators

• Dammam Medical Complex

  collaborator UNKNOWN

• Institute for Research and medical consultations (IRMC)

  collaborator UNKNOWN

• Imam Abdulrahman Bin Faisal University

  lead OTHER

Principal Investigators

• Mohammed S Alshahrani, MD · Critical Care and emergency Department, Associate Professor, College of Medicine, Imam Abdulrahman Ben Faisal University

• Iman Almansour, PhD · Associate Professor, Department of epidemic disease research, IRMC, IAU

• Mohamed R El Tahan, MD · Anesthesiology Department, Associate Professor, College of Medicine

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2020-08-31

Primary Completion

2020-12-31

Completion

2021-02-28

Countries

• Saudi Arabia

Study Locations