Donor Stem Cells Just As Good For Heart Patients
Donor stem cells taken from adult bone marrow (mesenchymal stem cells or MSCs) were found to be just as effective in treating diseased hearts as injecting patients with their own stem cells. These were the findings of a new study presented at a meeting in the US.
The findings, from the POISEIDON trial, are being presented at the American Heart Association's Scientific Sessions 2012 in Los Angeles this week, and the researchers also report them in an online-first article published in JAMA on 6 November.
Lead author Joshua Hare, a professor of medicine and director of the Interdisciplinary Stem Cell Institute at the University of Miami Miller School of Medicine in Florida, says in a statement:
"This cell therapy clearly had some clinical benefits and the mesenchymal stem cells from donors were just as safe as those from the recipient."
"Even in patients who had heart attacks several decades before treatment, both donor and recipient stem cells reduced the amount of scarring substantially, by one-third," he adds.
The study results also suggest using donor MSCs may speed up treatment.
When a person suffers a heart attack, there is damage to the heart muscle. This scarring (ischemic cardiomyopathy) is the most common cause of debilitating, and often fatal, congestive heart failure.
Evidence from previous research suggests MSCs may heal scarring from a previous heart attack and improve heart function.
MSCs are unique because antibodies in the immune system don't attack them (even if they are from another person).
For their study, Hare and colleagues recruited 30 patients with chronic ischemic cardiomyopathy and gave them various doses of MSCs. Half the participants received their own MSCs, while the other half received donor cells.
The purpose of the trial was to compare MSCs from the patients themselves against those harvested from donors.
The MSCs were injected directly into the damaged area of the heart using a catheter and needle tip. This was a new cardiac catheterization technique, which the study results suggest worked well.
The results show that scar tissue reduced by 33% in both groups, while heart function improved in 28% of the patients who received donor cells, and in 50% of those who received their own cells.
The advantage of using donor cells is it reduces the time taken to prepare the large quantities of MSCs needed for regenerating heart muscle (this study used between 20 and 200 million cells per patient). It can take 6 to 8 weeks to prepare sufficient cells. If these are already available from donors, then it cuts down the waiting time considerably.
Hare says that because antibodies don't attack MSCs, you can prepare donor cells in advance and store them until needed. For this reason, "perhaps using donor cells is the more feasible approach," he suggests.
The team is now planning to do a larger, placebo-controlled trial. This is a necessary step before MSCs can be used as a standard treatment for ischemic cardiomyopathy and congestive heart failure.