胚胎干细胞治疗黄斑变性失明疗效肯定

2014/10/27 10:42:25 本站原创 佚名 【字体:

共有18名患者接受胚胎干细胞移植。3年的随访结果表明胚胎干细胞安全,没有发生排除。


Embryonic stem cell trials for macular degeneration: a preliminary report

Researchers say that human embryonic stem cells have restored the sight of several nearly blind patients -- and that their latest study shows the cells are safe to use long-term.
According to a report published this week in The Lancet, the researchers transplanted stem cells into 18 patients with severe vision loss as a result of two types of macular degeneration, an eye disease that causes progressive loss of sight.
Nine had Stargardt macular degeneration, the leading cause of juvenile blindness, and nine had dry atrophic age-related macular degeneration, the most common cause of vision loss in people over 50. There are currently no approved treatments for either condition.
The Mayo Clinic defines macular degeneration as occurring when tissue in your macula, a spot in the center of your retina, thins and breaks down. Stem cells can help rebuild this tissue.
The study's patients were followed for up to three years. Researchers saw no signs of rejection of the cells and no abnormal growth, tumor formation or unwanted tissue types in any of the patients during that time period. On average, the vision of the patients improved about three lines on the standard eye chart.
Patients in a control group who did not receive a stem cell transplant did not show similar sight improvement.
"This is the first report showing that the cells are safe in the long term and that they can actually help people," said Robert Lanza, chief scientific officer at Advanced Cell Technology, which funded the study. Lanza says that in the lab, researchers have also turned these cells into mesenchymal stem cells in animals that can be used to prevent the paralysis caused by multiple sclerosis or to treat lupus; they can be even used to prevent pain.
"We treated a 75-year-old horse rancher whose vision was 20/400, which is legally blind, and one month after treatment, his vision had improved 10 lines, which is 20/40 -- and he can even ride his horses again," Lanza said. "Other patients report similarly dramatic improvements. It's made a huge difference in the quality of their life."
Lanza and his fellow researchers plan to begin Phase 2 clinical trials by the end of the year, in which they'll treat a larger number of patients and test for efficacy.
Study co-author Dr. Steven Schwartz, professor of ophthalmology at UCLA's Jules Stein Eye Institute, is cautiously optimistic.

文献
Steven D Schwartz et al. Embryonic stem cell trials for macular degeneration: a preliminary report.. The Lancet - 25 February 2012 ( Vol. 379, Issue 9817, Pages 713-720 )

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