Rare blood types are rare as the name suggests. They have a less occurrence in the general population, making them harder to find in times of medical emergencies. AB negative, B negative, and O negative are those rare blood groups.
For these rare blood groups, the significance of blood donation becomes crucial. By donating blood, individuals contribute to saving lives and improving healthcare outcomes for patients who require transfusions. Every donation can make a significant difference, especially for those with rare blood types who heavily rely on the generosity of donors.
Dr Shailesh Shetty S, Consultant, Emergency Medicine, Aster CMI Hospital, says, “Blood type prevalence varies across populations and geographic regions. While many people are familiar with the basic blood types (A, B, AB, and O), rare blood types pose unique challenges in maintaining an adequate blood supply for those in need. Understanding these rare blood types and encouraging regular blood donation can save lives and ensure the availability of diverse blood types when emergencies arise. Blood type O is the most common [63% world’s population] throughout the world. Rh+ blood is much more common than Rh- blood. A person can only give blood to someone with compatible blood antigens. People with Rh- blood can give blood to both Rh- and Rh+ recipients. However, those with Rh+ blood cannot give to Rh- recipients. AB negative is the rarest of the eight main blood types – just 1% of our donors have it.”
The rarity of a blood type is determined by the presence or absence of certain antigens on the surface of red blood cells. Dr Hari K, Consultant Physician, Apollo Clinic, T Nagar, Chennai explains some examples of rare blood types:
- AB Negative (AB-): AB- is considered to be the rarest blood type in the world, with less than 1% of the global population having this blood type.
- B Negative (B-): B- is also relatively rare, with only about 2% of the population having this blood type.
- A Negative (A-): A- is less common than A positive, with around 6% of the population having this blood type.
- AB Positive (AB+): While AB+ is rarer than the other positive blood types, it is still more common than the negative types mentioned above. Approximately 3-4% of the global population has AB+ blood.
- A1B Negative (A1B-): A1B- is a relatively rare blood type, occurring in about 1% of the population. It is formed when a person has both A and B antigens on their red blood cells and lacks the Rh factor.
- Bombay Blood Group (Oh): The Bombay blood group is extremely rare and is found in a very small number of individuals, primarily in India.
What makes these blood groups rare?
Despite being rare, demand for AB-negative blood is low and we don’t struggle to find donors with AB-negative blood. However, some blood types are both rare and in demand. This includes the Ro subtype, which is often used to treat people with sickle cell, only 2% of donors have it but demand for it is increasing by 10-15% each year.
Dr Shailesh Shetty S discusses how the combination of being rare and sought after makes people with these blood types very important donors.
- O- is a universal donor, which means that a person with this blood type can donate to anyone. A rare blood is on the basis of the blood group and below-given characteristics:
- One that is found in a frequency of 1 : 1000 random samples in a given population.
- From a blood transfusion point of view, rare blood is the one with red cells lacking a high-frequency blood group antigen.
- Besides, blood that lacks multiple common antigens may also be considered as rare since such donor’s blood may be useful for the transfusion recipient who has developed multiple antibodies to the corresponding antigen.
The following are rare blood types we have encountered over a period in India:
- “Bombay” (Oh) phenotype
– D -/- D –
- In(a+b-)
- Co(a-b-)
- A host of weaker variants of A, B and H antigens
- I-i-
- CdE/CdE (ryry)
- Mg
Can synthetic blood be an alternative?
Dr Anoop P, Consultant Hematologist, Aster RV Hospital, Bangalore, says, “Blood is an extremely useful natural resource in the treatment of sick patients. Extensive global research has still not been successful in manufacturing safe and cost effective synthetic blood. On most occasions, medicines cannot be a substitute for blood products. Hence donation of blood often saves lives, especially if you are a rare blood group donor.”
Among Asians, AB and Rh negative blood groups are uncommon. “Mismatched blood donation can worsen a patient’s condition and is not an option. Timely availability of rare blood group units can be very challenging and can directly impact treatment outcomes. Awareness of the importance of blood availability can potentially motivate young donors,” adds Dr Anoop P.
Importance of Blood Donation
Blood donation plays a crucial role in maintaining public health and saving lives. Blood transfusions are essential for patients undergoing medical treatments such as surgeries, organ transplants, cancer treatments, and trauma care. “Many medical conditions require regular blood transfusions to manage or cure them. Individuals with conditions like thalassemia, haemophilia, sickle cell disease, and certain types of cancer rely on blood transfusions as part of their treatment plans. Accidents, natural disasters, and other emergencies often result in a sudden and significant need for blood. In such situations, access to an adequate blood supply can be critical for treating injuries and saving lives,” states Dr Hari K.
In India, there is a need for blood every two seconds and to make this situation concerning, India has the highest number of anemic patients. Blood donations are important for individuals who require transfusion during surgeries, accidents, cancer treatments, and/or other emergencies. An adequate supply of blood is required during organ transplantations and complex surgeries too.
“The dependability on voluntary blood donors is high since the blood supply has to be consistent, there is no substitute for blood or plasma and it has a limited shelf-life. From the donor perspective, there are several health benefits of blood donation such as it stimulates new blood cell production, and lowers the risk of cardiovascular disease and cancers. It also helps in overall good health. The utmost reason, the immense satisfaction of extending a helping hand in the critical times cannot be ignored,” signs off Dr Shailesh Shetty S.
Blood donation is an act of generosity that strengthens the community. By giving blood, you contribute to the well-being of others and promote a sense of solidarity. Blood donation also raises awareness about the importance of voluntary donations and encourages others to participate in this lifesaving act.
