First-of-Its-Kind ‘CRIB’ Blood Group Found in Karnataka Woman, Stuns Experts

A 38-year-old woman from Karnataka’s Kolar district has stunned medical experts with the discovery of the CRIB blood group, a previously unknown antigen. Announced at the 35th Regional Congress of the International Society of Blood Transfusion (ISBT) in Milan, Italy, in June 2025, this world-first finding adds a new dimension to the Cromer blood group system, advancing rare blood group research.

How the CRIB Blood Group Was Found

The breakthrough occurred when the woman, admitted for cardiac surgery, tested as O Rh+, the most common blood group, but her blood was incompatible with all O-positive donor units. Dr. Ankit Mathur, a transfusion medicine expert at the Rotary Bangalore TTK Blood Center, led the investigation.

“Her blood reacted with all test samples,” Mathur explained. Despite testing blood from 20 family members, no compatible match was found. Remarkably, her surgery succeeded without a transfusion, prioritizing patient safety.

The case escalated to the Advanced Immunohematology Reference Laboratory at the Rotary Bangalore TTK Blood Center, which used advanced serological techniques to identify the anomaly. Blood samples were sent to the International Blood Group Reference Laboratory (IBGRL) in Bristol, UK, where ten months of molecular testing confirmed the new CRIB blood group.

Named CRIB (denoting “Cromer” (CR) and “India, Bangalore” (IB)), the antigen is a significant addition to the Cromer system, known for its complex glycoprotein structures.

Impact on Transfusion Safety and Organ Transplants

The CRIB blood group discovery enhances global transfusion safety and organ transplant compatibility. Its unique nature means the patient may need autologous transfusion, storing her own blood after boosting hemoglobin levels.

To support such rare cases, the Rotary Bangalore TTK Blood Center launched a Rare Donor Registry with Karnataka State Blood Transfusion, the Indian Council of Medical Research (ICMR) in Mumbai, and the ISBT. “This registry strengthens our ability to support patients with rare blood types,” Mathur said, citing prior successes with Rh null and In b negative cases.

India’s Role in Immunohematology Research

The CRIB discovery parallels the Gwada Negative antigen, identified in a woman from Guadeloupe living in Paris. India’s contribution to immunohematology research now stands prominent, with the CRIB blood group reinforcing the need for advanced donor registries and global collaboration to improve transfusion medicine.

(Rh/Eth/Pooja Bansal/MSM/SE)