ABSTRACT
Introduction: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), a new strain of RNA viruses causes coronavirus disease in human. Though some studies suggested different blood group types as risk factors for Coronavirus Disease 2019 (COVID-19) infection, the association between blood groups and the COVID-19 infection may not be the same in various societies with different genetic statuses. Also, no studies so far have investigated the relationship between COVID-19 severity and ABO blood groups in Iran and developing countries according to the World Health Organisation (WHO) criteria. Aim: To evaluate the association between blood types and the severity of COVID-19 infection. Materials and Methods: This cross-sectional study enrolled 171 patients infected with SARS-CoV-2 {49 severe (severe or critical) and 122 non severe (mild to moderate)}, who were admitted to hospitals of Mazandaran University of Medical Sciences, Sari, Iran from April 2020 to June 2020. To evaluate the distribution of the blood group, 171 COVID-19 patients were compared with the reported data of Iranian population blood groups. The severity of COVID-19 infection was determined based on WHO criteria including clinical symptoms, radiological findings, and signs of organ dysfunction. The associations between ABO blood groups and the severity of COVID-19, were evaluated using Pearson's Chi-square. Results: The distribution of the blood group in 171 patients with COVID-19 was not different compared to the reported general Iranian population blood group (p-value=0.344). Evaluation of the association between ABO blood groups and the severity of COVID-19 showed that patients with blood group type B developed severe COVID-19 infection compared to other blood types who showed mild or moderate conditions (p-value=0.048). Mortality due to COVID-19 was not statistically different between the ABO blood group and Rh (p-value=0.96, p-value=0.27 respectively), but the frequency of patients with Rh-negative that needed intubation and mechanical ventilation was higher compared to Rh-positive patients (p-value=0.003). Conclusion: A positive correlation was found between blood type B and COVID-19 severity. Also, mechanical ventilation was significantly more in Rh-negative patients.