Stem cell therapy may help mend a broken heart

Blausen.com staff (2014). “Medical gallery of Blausen Medical 2014

Dilated cardiomyopathy (DCM), a condition where the muscles of the heart are weak and can lead to heart failure, is considered rare in children. However, because the symptoms are not always easy to recognize the condition can go unnoticed for many years, and in severe cases can damage the heart irreparably. In that case the child’s only option is a heart transplant, and a lack of organ donors means that is not always available.

Now, new research out of Japan – published in the journal Science Translation Medicine – could lead the way to new treatments to help children avoid the need for a transplant.

In the study, researchers at Okayama University used heart stem cells called cardiosphere-derived cells (CDCs) to try and repair the damage caused by DCM.  

In a news release, lead researcher Professor Hidemasa Oh, says previous work has shown that because CDCs have the ability to turn into heart tissue they have the potential of reversing damage, but it’s not clear if this would work in children.

“I have been working on cardiac regeneration therapy since 2001. In this study, my team and I assessed the safety and efficacy of using CDCs to treat DCM in children.”

Tests in animal models with DCM showed that the CDCs resulted in a thickening of the heart muscle leading to increased blood flow around the body. This increased blood supply helped repair damaged tissue. Based on this trial the researcher determined what might be a suitable dose of CDCs for children with DCM and were granted permission to carry out a Phase 1 clinical trial.

Five young patients were treated and the results were cautiously encouraging. After a year none of the patients had experienced any severe side effects, but all had indications of improved heart function.

The study also gave the researchers some strong clues as to how the therapy seem to work. They found that when the CDCs were transplanted into the patient they secreted exosomes, which play an important role in cells communicating with one another. These exosomes then helped create a series of actions within the body; they blocked further damage to the heart tissue and they also helped kickstart the repair process.

The Okayama team are now hoping to carry out a Phase 2 clinical trial with more patients. Ultimately, they hope to be able to see if this approach could help prevent the need for a heart transplant in children, and even adults.