04-08-2025
Medical Mystery Unfolds: India Discovers Blood Type Never Seen Before; Scientists Stunned By Medical First
Bengaluru: A 38-year-old woman from Kolar district in Karnataka has been identified with a previously unknown blood group, now officially recognised and named CRIB by the International Society of Blood Transfusion (ISBT).
CRIB stands for Cromer India Bengaluru. 'Cromer' refers to the blood group system under which the antigen has been classified. 'India' indicates the country of discovery and 'Bengaluru' marks the city where the blood sample was studied.
The discovery was made during routine testing before the woman was scheduled for cardiac surgery. Doctors at RL Jalappa Hospital in Kolar faced difficulty finding compatible blood, prompting further investigation. When no match could be found from blood banks or among 20 family members, her sample was sent to the International Blood Group Reference Laboratory (IBGRL) in Bristol, the United Kingdom.
After 10 months of analysis, the IBGRL confirmed the presence of a previously unidentified antigen in the Cromer blood group system. This was then reported to the ISBT, whose Red Cell Immunogenetics and Terminology Working Party approved the new antigen and added it to the Cromer system as the 21st known antigen.
According to Dr. Ankit Mathur, additional medical director at the Rotary-TTK Blood Centre in Bengaluru, the patient's red blood cells reacted abnormally in all compatibility tests. 'We could not match her blood with any known group. After extensive testing and global reference checks, a new antigen was confirmed,' he said.
The patient underwent successful heart surgery without needing a transfusion. Due to the unknown blood group at the time, doctors avoided using stored donor blood.
The case highlights potential challenges in emergency transfusion scenarios involving patients with rare or unknown blood types.
Dr. Mathur explained that in such cases, autologous blood transfusion, wherein the patient's own blood is collected and stored before surgery, becomes essential.
The CRIB antigen is not present in any of the woman's family members. Genetic analysis indicates the antigen developed due to partial expression of genes from one parent, with no known complete match so far.
India has previously reported rare blood groups, including the Bombay blood group (hh), first discovered in 1952. CRIB is now added to the list of globally recognised rare blood antigens originating from India.
Dr. Swati Kulkarni, former deputy director at ICMR-NIIH, highlighted the importance of building a national rare blood donor registry. The registry would help match rare blood group patients with compatible donors, especially in high-risk or repeat transfusion cases like thalassemia.
The discovery was formally announced in June 2025 at the 35th International Congress of the ISBT held in Milan, Italy.
