ABSTRACT
The aim of this study is to evaluate the effect of blood groups (BGs) on Covid-19 contraction and prognosis and to reveal the coefficients. Patients who referred to Covid-19 outpatient clinics and had an established diagnosis of Covid-19 were included in the study. Their BGs, previous diagnoses and blood examination findings were retrospectively analyzed. Duration of hospitalization, clinical course and survival were recorded. The mean age of 365 subjects, 210 female and 155 male, was 45,5 years. Subjects with BG A developed Covid-19 at significantly higher rates (p = 0.001), while BG O was found associated with lower rates (p = 0.005). Lymphocyte count was found lower (p = 0.035) and rate of lung parenchymal involvement was higher (p = 0.003) in patients with Rh antigen. It was found that a higher percentage of patients with B BG required treatment in the intensive care unit (ICU) compared to other ABO BGs (p = 0.015). These results suggest a higher risk of Covid-19 contraction in the population with BG A and lower risk for BG O population while indicating poorer prognosis for patients with BG B. Copyright © 2022 Ondokuz Mayis Universitesi. All rights reserved.
ABSTRACT
OBJECTIVE: In this period when mutant strains are increasing all over the world, studies on how much humoral immunity will protect against the Severe Acute Respiratory Syndrome 2 (SARS-CoV-2) are quite limited. The aim of our study is to investigate the positivity and antibody levels of the COVID-19 reverse transcription polymerase chain reaction (RT-PCR) test, the frequency of SARS-CoV-2 re-infection, and the protective antibody level against re-infection. METHODS: Patients who were positive for COVID-19 IgG antibody between 1 July and 31 August were included in our study. The COVID-19 RT-PCR test positivity, age, gender and comorbidities of these patients were recorded before this date. The COVID-19 RT-PCR test positivity of these patients was followed from the National COVID-19 Database between September 1, 2020 and February 28, 2021. RESULTS: 1665 patients (female: male 683: 982, mean age 40.6+/-13.4 years). Among all patients, 14 patients had reinfection and the frequency of reinfection was 0.8%. It was observed that the frequency of reinfection was more frequent in patients with PCR negative (p<0.001). The IgG cut-off value causing reinfection was found to be 11.9 (AUC: 0.844, 79.2% sensitivity, 78.6% specificity) (p<0.001). CONCLUSION: Humoral antibodies against SARS-CoV-2 were protective against COVID-19 reinfection, 0.8% of the patients had reinfection and the resultant reinfection was mostly seen in PCR negative patients who were asymptomatic.