Related Experiment Video
Updated: Oct 28, 2025

Author Spotlight: Advancing Immune Monitoring in Critical Care Patients Using Whole Blood Assays
Published on: September 20, 2024
Blood system ABO antigens as risk factor for severity of SARS-CoV-2 infection
Carmen G Torres-Alarcón1, Antonio García-Ruíz2, Cesar R Cañete-Ibáñez3
1Blood Bank Department.
Introduction:
Whether there is an influence of the ABO blood system on SARS-CoV-2 infection is unknown.
Objective:
To analyze if there is an association between the ABO system antigens and susceptibility to and severity of SARS-CoV-2 infection.
Material And Methods:
The frequency of ABO system antigens was compared in 73 confirmed cases of SARS-CoV-2 infection and 52 clinically healthy donors. Infection severity was assessed by comparing the frequency of antigens by disease severity and mortality.
Results:
The risk of suffering from SARS-CoV-2 infection increases in subjects with A vs. non-A antigen (OR = 1.45; 95 % CI: 1.061-1.921). Blood phenotype O reduces the risk of SARS-CoV-2 infection (OR = 0.686; 95 % CI: 0.522-0.903). No differences were found regarding disease severity. In critically ill patients, the risk of mortality increased in subjects with A vs. non-A antigen (OR = 3.34; 95 % CI: 1.417-8.159).
Conclusion:
Blood group A is a risk factor for SARS-CoV-2 infection, but not for disease severity, although in critically ill patients it is a risk factor for mortality.
More Related Videos
Related Concept Videos
The ABO Blood Group
Antigens in the ABO Blood Group System
Antigens are substances that can trigger an immune response, leading to the production of antibodies. In the ABO blood group system,...
Blood Transfusion
Blood Transfusion Overview
A blood transfusion is a medical procedure used to replace blood lost due to injury, surgery, or to treat conditions such as anemia or cancer. During a transfusion, donor blood is...
Blood Transfusion and Agglutination
History
The history of blood transfusion dates back to the 17th century, when early attempts were made in animals. In 1818 James Blundell, a British doctor, performed the first successful human blood transfusion. Later in 1900, Karl...
Blood Types
ABO blood group
ABO antigens are glycoproteins encoded by genes present on...
Blood Typing
Antigens are protein molecules that reside on the surface of red blood cells (RBCs). The ABO and Rh blood typing systems target...
Rh Blood Group

