COVID-19 patients with blood group A have a higher risk of becoming severe cases compared to non-A blood groups

Background
The risk factors associated with COVID-19 disease severity are still being investigated. Individual susceptibility to viral infections has been known to be associated with the ABO blood group.

Objectives
This study aims to determine the association between the ABO blood group and disease severity in COVID-19.

Material and methods
This is an observational study with a prospective design. Patients were followed during treatment, and clinical outcomes were recorded, being severe or mild-moderate cases. A total of 207 confirmed COVID-19 patients who underwent treatment from November 2020 to January 2021 were included in this study. Chi-square analysis was used to determine the association between blood group A and other blood groups with the occurrence of severe cases. Multiple logistic regression analysis was used to obtain the adjusted odds ratio (OR) and determine the effect of confounding variables.

Results
We found a significant association between blood group A and disease severity, though not for any other blood group. By using multiple logistic regression analysis, blood group A was independently associated with disease severity with an adjusted OR (95% confidence interval (CI)) of 2.36 (1.07–5.23) (p = 0.034).

Conclusions
COVID-19 patients with blood group A have a higher risk of becoming severe cases compared to non-A blood groups.