BENGALURU, INDIA: Indian scientists have made a groundbreaking discovery in transfusion medicine and immunohematology. They identified a new and extremely rare blood group antigen called CRIB (Cromer-India-Bangalore) in a 38-year-old woman from Kolar district, Karnataka, after months of intensive testing and collaboration.This finding was officially recognized by the International Society of Blood Transfusion (ISBT) in June 2025, marking the first time this antigen has been identified in a human. It is considered one of the most significant contributions to global hematology in recent decades.

The Case That Shocked the Lab 

The situation began when the woman went to the Rotary Bangalore TTK Blood Centre for a routine pre-surgical blood test. Initially, she was typed as O Rh-positive. However, her blood showed an unusual reaction—it was incompatible with all available donor samples. This rare situation, known as pan-reactivity, prompted immediate further investigation by the center's skilled team of immunohematologists.“We knew we were dealing with something extraordinary,” said Dr. R.S. Hemalatha, chief immunohematologist at the center. “Her blood didn’t just mismatch—it resisted all known compatible blood types. That kind of reaction is a sign of rare or unknown antigens.”

A Decade's Worth of Science in 10 Months 

The center initiated an extensive molecular and serological testing campaign. When local expertise and technology couldn’t solve the puzzle, samples were sent to the International Blood Group Reference Laboratory (IBGRL) in Bristol, United Kingdom. Known for verifying new blood antigens globally, the IBGRL conducted nearly 10 months of analysis.Finally, in mid-2025, IBGRL confirmed that the woman’s red blood cells contained a previously unclassified antigen in the Cromer blood group system, which is linked to the Decay-Accelerating Factor (DAF) protein. This protein is known to play a role in the body’s immune defense.The antigen was unique compared to other known Cromer variants, leading to the name CRIB, which stands for Cromer-India-Bangalore. This naming not only places India on the global map of hematological research but also recognizes the dedication of the local medical team.

What Makes CRIB So Unique? 

The Cromer blood group system is rare, consisting of a family of antigens on the DAF protein. Changes in this protein can lead to new antigenic structures, like CRIB. These antigens are inherited and are not detected through standard ABO or Rh typing.The Kolar woman is the only known person in the world with CRIB. This makes her blood not only unique but also highly vulnerable. In case of trauma, surgery, or any situation needing a transfusion, finding compatible blood would be a major challenge.

The Threat to Patient Safety 

For patients like her, typical transfusion methods can be life-threatening. If she receives blood with antigens her immune system does not recognize, her body might initiate a serious response, causing hemolytic transfusion reactions, which can be fatal.Her case highlights the urgent need for rare blood donor registries and international cooperation. According to Dr. Hemalatha, “This is not just about one patient. CRIB opens the door to identifying more people with rare or unknown antigens. We must build databases, promote global exchanges, and update screening protocols.”

India’s Growing Role in Global Blood Science 

India, known for its rich genetic diversity, is becoming a hub for rare blood group discoveries. The discovery of CRIB reinforces this role and points to the importance of investing in better diagnostics, genetic research, and worldwide data sharing.Organizations like the Rotary Bangalore TTK Blood Centre are at the forefront with top-notch facilities and trained professionals. Their work on CRIB illustrates the value of vigilance, training, and scientific rigor in uncovering what may be hidden.

Global Recognition at ISBT Congress 

In a notable moment for India’s scientific community, the discovery was formally recognized at the International Society of Blood Transfusion (ISBT) Congress in Milan, Italy, in June 2025. CRIB has now been added to the international registry of blood group antigens.This means medical institutions worldwide will start updating their databases, and blood banks may soon begin screening for the CRIB antigen, especially in South Asian populations.

The Path Forward: Building Rare Donor Registries 

The discovery of CRIB is a strong reminder for the medical community to focus on rare blood types. India needs to:- Create a national rare blood donor registry.- Fund genetic screening programs.- Educate the public on the importance of blood donation for rare types.- Promote cross-border cooperation for rare blood sharing.Only then can cases like this be managed effectively without risking lives.

A Singular Discovery with Global Ramifications 

The CRIB blood group discovery marks a pivotal moment in medical science. While it currently affects only one known individual, its implications are far-reaching and could improve outcomes for patients with rare or poorly understood blood types globally.Dr. Hemalatha captured it well: “This is not just a case study. It’s a guiding light for future research, better preparedness, and a deeper understanding of human biology.”