More deaths when blood transfusion donor young, woman, study suggests

Patients who receive blood transfusions from younger or female donors are more likely to die, according to a study lead by a Quebec researcher.

Researcher, blood banks taking results 'very seriously' but not changing practice until links confirmed

If the study's results are confirmed, it could be the start of more personalized blood transfusions. (Ryan Remiorz/Canadian Press)

Patients who receive blood transfusions from younger or female donors are more likely to die, according to a study co-authored by a Quebec researcher.

The wide survey, conducted by researchers affiliated with the Ottawa Hospital Research Institute (OHRI), shows a clear link between the age and gender of donors and the risk of death in blood transfusion recipients the following year.

For example, patients who received six units of red blood cells from a female donor had a 36 per cent mortality rate the year after the transfusion, compared to 27 per cent when the donor was male.

Similarly, survival rates decrease by 8 per cent when patients received blood from donors under 20, compared to donors between 40 and 50 years old.

Researchers surprised

The results, released this week, were a surprise to the researchers themselves.

They expected the "younger" blood to be more efficient, according to the study's first author, Dr. Michaël Chassé, an intensive care physician at CHU de Québec who was formerly affiliated with the OHRI.

Though researchers are still speculating as to why these characteristics affect recipients differently — if at all — they believe it has something to do with the donor's immune system.

It's a very well done study and we should take these results very seriously … That said, we shouldn't jump to conclusions.- Marc Germain, Héma-Québec's vice-president of medical affairs

"Young people have an immune system that is more active and aggressive against invasions," Chassé said. He added that this could be the reason a reaction is present in the recipient.

Chassé and his colleagues were able to analyze the anonymous medical records of 30,503 patients who received 187,960 blood transfusions from 80,755 separate donors thanks to a collaboration with Canadian Blood Services (CBS) and four Ontario hospitals.

They were able to follow the group over seven years and compare the survival rate of patients who received blood from donors of different ages and genders.

However, even if the results are statistically significant, Chassé stressed that it does not constitute a causal link between the age or sex of a donor and the health of a recipient.

"We should not change our transfusion practices based on a single study. It is the first to have made this observation and it has yet to be confirmed," he said.

Chassé, who prescribes transfusions to his own patients, added that blood transfusions have never been safer in Canada.

Blood banks take results 'very seriously,' but not worried

On their end, blood bank managers are following these new observations very closely.

"It's a very well done study and we should take these results very seriously," said Marc Germain, Héma-Québec's vice-president of medical affairs.

"That said, we shouldn't jump to conclusions," he said.

Germain said it was important to identify the specific factors in women and young people's blood that could affect health before categorizing according broad criteria such as age or gender.

He did concede, however, that if certain links were confirmed, practices would have to adapt.

For its part, the CBS believes its data could lead to a better understanding of donor characteristics on a recipient's health.

Should the study's findings be confirmed, it could open up the way for more personalized care in the field of transfusions, eventually allowing doctors to transfuse blood depending on the compatibility of the donor and recipient, particularly with regards age and gender.

With files from Radio-Canada's Jean François Bouthillette