# Relationship between blood group (ABO) and risk of COVID-19 infection in a patient cohort in Tehran, Iran

## TL;DR

This study found that people with blood type A are more likely to contract COVID-19 compared to those with blood type O.

## Contribution

The study provides evidence of a significant association between ABO blood types and susceptibility to COVID-19 infection.

## Key findings

- 100% of patients with confirmed COVID-19 had blood type A.
- Blood type A showed a significantly higher ratio compared to blood type O (P=0.009).
- The study suggests blood type A individuals are at higher risk of infection than blood type O individuals.

## Abstract

Background and purpose. Coronavirus (COVID-19) is a contagious disease causing severe acute respiratory syndrome which had a catastrophic effect on the world population and resulted in more than 2.9 million deaths worldwide. Epidemiological investigations have recently announced blood type has an association with the incidence of COVID-19 infection. Consequently, research in this regard can be effective in determining a person’s susceptibility to a viral infection. Therefore, we investigated the relationship between blood types and the risk of COVID-19 in patients admitted to Khorshid laboratory, Tehran, Iran.

Materials and methods. From January to March 2020, 50 nasal and throat swapb samples of patients’ secretions were obtained from patients who were admitted to Khorshid laboratory. They were confirmed to have COVID-19 virus RNA and real-time polymerase chain reaction (PCR)-ABI, and their blood type was determined simultaneously. After collecting data to determine the relationship between COVID-19 infection and blood type, a confidence interval of 90 % was considered using SPSS 16.

Results. The mean age of the patients was measured at 38.4±6.3 years. According to PCR results, 100 % of the subjects with COVID-19 showed blood type A. In addition, the ratio of blood type A to the percentage of reference type O was higher (P=0.009).

Conclusion. There was a significant relationship between ABO blood type and susceptibility to COVID-19. As the current study suggests, those with blood type A are at a higher COVID-19 infection risk than those with blood type O.