World's first rare blood group found in Bangalore woman, marking a historic medical discovery

In a historic medical breakthrough, researchers have discovered a previously unknown blood group in a 38-year-old woman from Kolar district, Karnataka. This extraordinary finding came to light when she was admitted for cardiac surgery and her blood type was found to be incompatible with all available O-positive donor units, despite being categorised as O Rh+. The case was escalated to the Rotary Bangalore TTK Blood Centre and later to the International Blood Group Reference Laboratory (IBGRL) in the UK, leading to the identification of a new antigen – CRIB. This rare discovery has global significance, advancing rare blood group research, improving transfusion medicine safety, and strengthening international collaboration in immunohematology.


Rare blood mystery as O Rh+ type shows universal incompatibility before surgery


The patient, initially identified as O Rh+; the most common blood group, required a routine transfusion ahead of cardiac surgery. However, none of the standard O-positive blood units were compatible. The hospital referred the case to the Advanced Immunohematology Reference Laboratory at the Rotary Bangalore TTK Blood Centre.

“Using advanced serological testing, we found her blood was ‘panreactive’, meaning it reacted with all available samples. Recognising the likelihood of a rare or unidentified blood antigen, we tested 20 family members for compatibility, but none were a match,” noted Dr. Ankit Mathur from the Rotary Centre. Remarkably, her surgery was successfully completed without transfusion, and her samples were sent to IBGRL in Bristol, UK, for further analysis.



First-ever CRIB antigen found in Bangalore woman





After ten months of research and molecular testing, international experts identified a new antigen in the Cromer (CR) blood group system. In recognition of its origin, the antigen was officially named CRIB—with “CR” representing Cromer and “IB” for India, Bangalore.

The discovery was publicly announced at the 35th Regional Congress of the International Society of Blood Transfusion (ISBT) in Milan, Italy, in June 2025. This marks the woman as the first individual globally confirmed with the CRIB antigen. To support individuals with rare or newly identified blood groups, the Rotary Bangalore TTK Blood Centre has established a Rare Donor Registry in partnership with Karnataka State Blood Transfusion, IIH (ICMR, Mumbai), and with support from the International Society of Blood Transfusion.

“This discovery reinforces India’s contribution to rare blood group research. We have previously supported multiple rare blood type cases, including Rh null and In b negative, all documented and presented internationally,” added Dr. Mathur.



Rare blood group breakthrough improves future organ transplant and transfusion safety

Rare blood types pose serious challenges in emergency transfusions, organ transplants, and complex surgeries. Identifying new antigens like CRIB enhances global transfusion safety, improves compatibility testing, and lays the foundation for better donor matching in future medical emergencies. This breakthrough positions India as a key player in global immunohematology research and sets the stage for improved awareness and advanced donor registries for rare blood groups worldwide.




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