In a pioneering breakthrough in transfusion science, a woman from Bengaluru has been diagnosed as the first documented case globally of a newly classified extremely rare blood type, termed CRIB.
This rare group, known as Chromosome Region Identified as Blood group (CRIB), is a new antigen within the INRA (Indian Rare Antigen) system, linked to the Cromer blood group family, yet containing a previously undetected marker.
The woman’s blood was incompatible with all known donor samples, including close relatives, displaying panreactivity—a condition where her immune system rejected all standard matches.
CRIB-negative individuals lack a high-frequency antigen present in most humans, making blood transfusion exceptionally challenging. Only donors with an identical CRIB-negative profile can safely donate—a statistical rarity worldwide.
Its discovery is crucial in managing pregnancy complications such as Hemolytic Disease of the Fetus and Newborn (HDFN), where the mother’s antibodies attack fetal red blood cells. Early detection of CRIB can help prevent severe outcomes during gestation.
The group was first identified in a patient from Gujarat, where even global rare blood banks failed to find a match. Genetic evaluation confirmed a novel antigen structure, prompting the International Society of Blood Transfusion to officially recognize CRIB.
Researchers now call for CRIB-specific screening tools, nationwide rare donor databases, and increased awareness in maternal health practices, especially in ethnically diverse regions like India.