Friday, Oct. 12, 2012

NEW YORK A team of researchers has transplanted artificial cardiac muscle cells developed from multipurpose stem cells into six patients in the United States in the world's first clinical application of iPS cells, one of the researchers said Wednesday.

Shinya Yamanaka, who won this year's Nobel Prize in medicine or physiology for his development of iPS cells, declined comment on the transplants, while other experts said details about the medical performance should be carefully evaluated.

The researchers developed the muscle cells from induced pluripotent stem cells produced from the patients' livers and transplanted them to the patients, said Hisashi Moriguchi, a visiting professor at Harvard University.

A 34-year-old American male patient who was the first to receive the transplant in February now has normal heart functions and has been discharged from the hospital, Moriguchi said.

The patient suffered from liver cancer and received a liver transplant in February 2009. He developed ischemic cardiomyopathy this February, prompting the researchers to conduct the heart surgery.

The researchers took cells from the patient's original liver, which was kept after removal for the 2009 transplant, and developed iPS cells by adding protein and other medical agents from which they produced cardiac muscle cells. The muscle cells were placed in 30 locations in the patient's heart.

No rejection or cancer development was found in the heart, and his heart function gradually recovered to normal levels 10 days after the surgery, they said.

"We need to improve the efficacy and safety of such medical treatment . . . and think of ways to reduce economic burden on patients," Moriguchi said.

The researchers used an improved technique to produce iPS cells developed by Yamanaka, the professor from Kyoto University who jointly won this year's Nobel with John Gurdon of Britain. Such cells have the potential to grow into any type of body tissue.

Read more:
U.S. marks first iPS clinical applications