Blood from Young Donors Does Not Improve Survival
In 1950s, Clive McCay of Cornell University in Ithaca, New York, joined together the circulatory systems of an old and young mouse, a technique called heterochronic parabiosis. He found that the cartilage of the old mice soon appeared to be younger than expected.
More than fifty years later, Thomas Rando at Stanford University in California used heterochronic parabiosis to infuse young blood into old mice. They reported that young blood returned hepatic and skeletal stem cells of old mice to a more youthful state. Old mice were able to repair injured muscles as efficiently as young mice (Nature, doi.org/d4fkt5).
Several other experiments have shown similar effects. In 2012, Amy Wagers at Harvard University connected the circulatory systems of young and old mice and showed that young blood reversed cardiac hypertrophy in old mice. Later, this research team determined that a plasma protein, growth differentiation factor 11 (GDF 11) was a significant rejuvenation factor. (https://www.newscientist.com/article/dn23511-young-blood-reverses-heart-decline-in-old-mice).
Following these successful animal studies, researchers were hopeful that transfusion of blood from young donors may have similar rejuvenating effects for older human patients. Researchers in Sweden and Denmark used a match cohort study to examine the potential positive effects of blood from younger donors. Patients receiving red blood cells or plasma from donors less than 25 years old were matched to three controls from older donors. The study included more than 45,000 plasma recipients and more than 136,000 RBC recipients, and was adjusted for recipient age, sex, and the number of transfusions. Donor age was not associated with either 30-day or 1-year mortality after plasma or red blood cell transfusions. Subgroup analysis did not show any differences in patients with dementia, cardiovascular or cerebrovascular disease. Unfortunately, blood from younger donors did not seem to be associated with patient survival.
Vasan SK, Chiesa F, Rostgaard K, Magnusson PK, Halmin M, Nielsen KR, Titlestad KE, Hjalgrim H, Edgren G. Lack of association between blood donor age and survival of transfused patients. Blood 2016;127: 658-61.
