Longevity Briefs: Young Blood Plasma Reduces Inflammation Post-Surgery

Longevity briefs provides a short summary of novel research in biology, medicine, or biotechnology that caught the attention of our researchers in Oxford, due to its potential to improve our health, wellbeing, and longevity.

The problem:

It has been known for a long time now that blood or blood plasma (blood with all the cells removed) from young animals can rejuvenate older animals. For example, old mice given injections of plasma from young mice live longer and have healthier organs. This is thought to be explained by a combination of two factors. Firstly, infusions of plasma dilute harmful signalling molecules in the blood that are associated with ageing. Secondly, blood from younger organisms contains higher concentrations of beneficial signalling molecules that can rejuvenate aged tissues.

Several companies are trying to narrow down exactly which components of young blood plasma are beneficial and design treatments around them. So far, there is not much human evidence that plasma tranfusion is beneficial outside of standard clincial practice, with the health agencies recommending against seeking plasma treatments for rejuvenation. However, human trials are slowly starting to provide some results, such as this trial looking at the effects of plasma transfusion post-surgery.

The discovery:

In this trial, researchers recruited 55 participants mostly in their 60s and 70s who received hip and knee replacements, though only 36 participants completed the tria,mainly due to disruptions caused by the Covid-19 pandemic. The participants were randomised to receive either placebo treatments in the form of saline solution, or GRF6021, a proprietary plasma fraction from donors with an average (mean) age of 35. They received these infusions immediately before and after surgery, as well as one day before and one day after surgery. Since one of the main objectives was to see how the treatment affected inflammation, which is known to impact healing and recovery, drugs that could affect the immune system such as corticosteroids were avoided.

Researchers then studied the protein and cellular composition of the participants’ blood and found that GRF6021 had a significant impact on inflammation immediately after surgery. Signalling pathways related to inflammation were affected, as were receptors for inflammatory signals. These effects seemed to be restricted to cells of the adaptive immune system – the branch of the immune system that recognises, attacks and remembers specific pathogens. Cells of the innate immune system – which triggers inflammation in response to anything and everything not belonging to the body – were not signifcantly affected by the treatment. Patients receiving GRF6021 had significantly lower levels of opioid use for pain relief, suggesting a reduction in pain post-surgery. However, there was no significant difference in patient outcomes such as surgery recovery scale (which includes the patient’s ability to perform everyday activities), though there was a trend for faster recovery from pain and fatigue in the treatment group.

The implications:

While the outcomes in this study were perhaps not as impressive as we would hope, this is the first human evidence that young blood plasma can have beneficial effects on the immune system in the elderly, at least in the context of surgery. The treatments given before the surgery did not have any significant effects on the immune system, but larger studies might be able to reveal other significant benefits that this study was too small to detect. It’s also a possibility that blood fractions from younger donors would have had more powerful effects.