Anu Thomas: Understanding the ABO Blood Group System and Its Formation
Anu Thomas, Assistant Professor at Government Medical College, Kozhikode, shared a post on LinkedIn:
“Understanding the ABO Blood Group System and Its Formation
The ABO blood group system is one of the most important classifications in transfusion medicine.
It plays a critical role in ensuring safe blood transfusions and organ transplants.
This system is based on the presence or absence of specific antigens – A and B antigens – on the surface of red blood cells:
- Group A – Has A antigen and anti-B antibodies
- Group B – Has B antigen and anti-A antibodies
- Group AB – Has both A and B antigens and no antibodies
- Group O – Has no antigens but both anti-A and anti-B antibodies
How is it formed?
The ABO blood group is genetically determined and inherited from parents.
It is controlled by the ABO gene, which exists in three forms (alleles): A, B, and O.
- The A and B alleles are co-dominant, meaning both are expressed if present together.
- The O allele is recessive, meaning it only appears when both inherited alleles are O.
These genes influence the production of enzymes that modify the surface of red blood cells, leading to the formation of A or B antigens – or neither in the case of group O.
Why is it important?
Compatibility in the ABO system is crucial. Mismatched transfusions can lead to serious, even life-threatening reactions due to immune responses.
Understanding this system is fundamental in clinical practice, blood banking, and patient safety.”

Stay updated with Hemostasis Today.
-
Jun 26, 2026, 18:28Daniel Pereira Monteiro: Why Is Beta Thalassaemia Major so Severe?
-
Jun 26, 2026, 18:27Pradip Pawar: Cell and Gene Therapy – Transforming Medicine in the 21st Century
-
Jun 26, 2026, 18:26Aviva Schwartz: How Can We Better Protect Patients After an Ischemic Stroke?
-
Jun 26, 2026, 18:25Does Reversing Factor Xa Inhibitors Really Carry as Much Thrombotic Risk as We Think? – RPTH Journal
-
Jun 26, 2026, 18:25Akshat Jain: Novel Therapies in Childhood Blood and Cancer Disorders
-
Jun 26, 2026, 16:57Abdul Muqtadir Abbasi: Anticoagulation in DVT Patients With Hidden Varices Requires Extreme Caution
-
Jun 26, 2026, 16:42Anesa Mulabecirovic: Why Von Willebrand Disease Takes Years to Diagnose in Women
-
Jun 26, 2026, 16:32Kaitlin Lichty: A New Identity Reflecting a Shared Legacy of Bleeding Disorders
-
Jun 26, 2026, 16:07Toong Youttananukorn: The WFH Registry Driving Better Care and Advocacy