Why should we say no to blood donations from close relatives?

In the past, a popular TV advertisement in Bangladesh depicted two young siblings whose mother needed a blood transfusion. They innocently asked, "Who will donate blood for us?" This ad highlighted the importance of blood donation, which was primarily sourced from professional donors at that time.

To curb the spread of blood-borne diseases, the health department initiated a campaign promoting voluntary blood donations from close relatives, transforming it into a social movement. By the late 2000s, professional donors comprised around 47% of all donors, but this figure dropped to below 10% by 2011.

However, medical science is ever-evolving, and research revealed that blood transfusions from close relatives could pose significant health risks, including severe complications like Transfusion-Associated Graft Versus Host Disease (TA-GVHD). 

This condition, which can even lead to death, became a focal point of new awareness campaigns. Consequently, the slogan "Say No to Blood from Close Relatives" gained traction, urging people to be cautious about receiving blood from family members.

Understanding genetic risks

The core issue lies in genetic similarity. Blood from family members, particularly those sharing 50% or more genetic similarity (like parents, siblings, or biological children), can increase the risk of TA-GVHD. This happens because the immune system fails to recognize some blood components as foreign due to genetic overlap. 

Patients with weakened immune systems, such as those undergoing chemotherapy, organ transplants, or with congenital immunodeficiencies, are at higher risk. In these cases, the immune cells in the transfused blood may attack the recipient's body, resulting in a mortality risk of up to 90%.

Who are considered blood-related relatives?

Blood-related relatives are classified into three categories: First-degree relatives, as in parents (biological mother and father),  siblings (brothers and sisters) and biological children.

Then there are second-degree relatives, as in grandparents (maternal and paternal), grandchildren, aunts and uncles (parents' siblings), and nephews and nieces (siblings' children).

Lastly, we have third-degree relatives that are cousins (children of aunts and uncles).

The risk of TA-GVHD is highest with first-degree relatives due to their high genetic similarity. In families with a history of intermarriage, even second- or third-degree relatives could pose a risk.

Striking a balance between awareness and need

Social media plays a significant role in spreading awareness but can also spread misinformation. For instance, in an effort to avoid risks, patients' attendants sometimes refuse blood donations from relatives, even when it is safe and necessary, leading to critical shortages. The distinction between "close family members" and "distant relatives" is often misunderstood, causing undue hesitation.

Despite advances in science, there is no artificial substitute for blood. Therefore, while caution is essential, rational and informed decisions are equally crucial. Let's embrace scientific evidence and make balanced choices to ensure the availability of life-saving blood donations without unnecessary fears.

Dr Ashraful Hoque is an Assistant Professor at the National Institute of Burn & Plastic Surgery.

Photo: Courtesy