2.1. Patients and healthy controls
For primary screening, the total number of 120 cases, including 97
COVID-19 patients and 23 healthy controls, were recruited in this study.
Healthy control samples were collected from the Blood Transfusion
Organization of Iran 5 months before the COVID-19 epidemic in Iran and
stored at -20 °C. All patients were laboratory-confirmed positive for
SARS-CoV-2 by real time PCR using throat or nasopharyngeal swab
specimens. Patients’ sera were collected during routine clinical testing
and incubated at 56 °C for 30 minutes to inactivate viruses and then
stored at -20 °C until use. The mean age and standard deviation of
patients and controls were 58.6±15.8 and 50.5±5.1, respectively. The
patients group included 63 male and 34 female subjects, and the healthy
control group included 18 males and 5 female individuals. All patients
were admitted to Imam Khomeini hospital affiliated to Tehran University
of Medical Sciences. Physical examination and pulse oximetry were
performed for all patients, and chest CT scanning was performed for
suspicious cases. Patients with the following criteria were admitted; 1)
saturation of oxygen (SpO2) level <93% without supplementary
oxygen and 2) characteristics of COVID-19 disease on the patient’s CT
scan, i.e., involvement of more than half of the lungs. Also, patients
with comorbidities and severe symptoms or signs of COVID-19 on their CT
scan with normal SpO2 levels were admitted. Major clinical
manifestations observed in patients include fever, cough, dyspnea, and
low blood oxygen saturation levels. Serum samples were collected from
all patients 3-7 days after hospital admission.
Patients were classified into severe and non-severe groups. Severe
illness included patients who had SpO2 <60% or required
intensive care unit (ICU) or received invasive (mechanical) ventilation.
Altogether, 49 patients (50.5%) were classified as severe, and 48
patients (49.5%) were non-severe.
Subsequently, 66 of 97 screened patients with the highest levels of NP
and RBD-specific antibodies were selected for Pepscan analysis. The mean
age and standard deviation of the selected patients were 59.6±15.1. They
included 44 male and 22 female patients which 45 (68.2%) were in severe
condition of disease and 21 (31.8%) were non-severe.
This study was approved by the Ethical Committee of the National
Institute for Medical Research Development (NIMAD) of Iran
(IR.NIMAD.REC.1399.194). Written consent was obtained from all patients
included in this study or their legal representatives.