Scientists in the US have found that regular infusions of blood plasma from young donors are safe to explore as a treatment option for people living with Alzheimer's disease. The results from the PLASMA trial, short for Plasma for Alzheimer's Symptom Amelioration, are presented at Clinical Trials Alzheimer's Disease Conference in Boston. 

Infusions of blood plasma, the liquid, cell-free part of the blood, are routinely used in surgery and to treat conditions like hemophilia and liver disease. Previous research in mice found that regular infusions of blood plasma from young mice improved memory in older mice.

The PLASMA trail aims to build on these findings and is testing the safety, tolerability, and feasibility of administering blood plasma from younger people to those living with Alzheimer's disease.

Researchers worked with 18 volunteers with mild to moderate Alzheimer's disease who received four, weekly infusions of either a placebo saline solution or blood plasma from donors aged between the ages of 18 and 30. After this four-week period, there was a six-week 'wash-out' period during which participants didn't receive either infusion.

The researchers then switched which infusions participants received so that those who previously had plasma received the placebo and vice-versa. The participants also took part in memory and thinking tests and assessments of functional skills – their ability to carry out everyday tasks.

The findings presented at the conference indicate that the blood transfusions were safe and that there were no serious side effects. The researchers also pointed to possible hints of plasma infusions leading to a benefit in participant's functional skills. Researchers are planning to further study the potential effects on patients.

Dr. Carol Routledge, Director of Research at Alzheimer's Research UK said:

"Blood-plasma infusions have been in widespread use for medical purposes for a number of years, so while it is not surprising that they were found to be safe in this research, it is good news that this interesting approach can now be investigated in larger trials.

"This study of 18 people focused on the safety of the blood transfusions and was not set up to assess potential benefits of people's symptoms. While the researchers point to potential signs of improvements, we need to see much larger studies before we can tell if this interesting approach could help improve the lives of people living with Alzheimer's disease.

"Alzheimer's is the most common cause of dementia, affecting half a million people in the UK, and urgently need treatments capable of stopping the disease in its tracks. Continued investment in research is vital to allow scientists to explore every angle in the search for treatments that could make a real difference to people's lives."