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One stem cell treatment stabilizes macular degeneration, another blinds 3 patients

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Story highlights

A 77-year-old Japanese woman with age-related macular degeneration received a treatment of her own cells

Though her eyesight hasn't improved, it has stabilized, researchers say

In Florida, three elderly women were blinded by a different experimental stem cell treatment

CNN —  

As we grow older, a common disease called macular degeneration can threaten our eyesight. An experimental stem cell treatment proved effective at halting this disease with no serious side effects up to a year later, a study published Wednesday in the New England Journal of Medicine found. It is the first treatment using personalized, genetically identical cells derived from the patient.

However, serious concerns about such research persist. Three women with macular degeneration were blinded in 2015 after undergoing a stem cell treatment at a clinic in Florida. The patients experienced a variety of complications and are now blind, according to a paper published Thursday in The New England Journal of Medicine.

The macula is the spot in the center of your eye’s retina. When that tissue begins to thin and break down, this is referred to as macular degeneration, a blurring of the sharp central vision necessary for driving, reading and other close-up work. Most people develop this disease as they age.

For the latest study, researchers led by Dr. Michiko Mandai of the laboratory for retinal regeneration at RIKEN Center for Developmental Biology in Japan tested an experimental stem cell treatment on a 77-year-old woman diagnosed with “wet,” or neovascular age-related, macular degeneration.

The “wet” form of the disease involves blood vessels positioned underneath the pigment epithelium (a layer of retinal cells) growing through the epithelium and harming the eye’s photoreceptor cells. In Japan, wet age-related macular degeneration is the most common form, but in Caucasian populations, only about 10% of people with age-related macular degeneration gets that form.

The “dry” form involves the macula breaking down without growth of blood vessels where they’re not supposed to be.

To stop the progress of wet macular degeneration, the researchers performed surgery to transplant a sheet of retinal pigment epithelial cells under the retina in one of the patient’s eye.

The transplanted cells had been derived from autologous induced pluripotent stem cells, which are reprogrammed cells. They were created using cells from the connective tissue of the woman’s skin.

One year after surgery, the transplanted sheet remained intact, and there was no evidence of lasting adverse effects. Although the patient showed no evidence of improved eyesight, her vision had stabilized.

“This research serves multiple purposes,” wrote Peter Karagiannis, a science writer, in an email on behalf of Dr. Shinya Yamanaka, the Nobel Prize-winning co-author of the study and director of the Center for iPS Cell Research and Application at Kyoto University. From the patient’s perspective, the study shows that induced pluripotent stem cells can alleviate the problems associated with age-related macular degeneration.

“From a greater medical perspective, however, the bigger impact is that it shows iPS cells can be used as cell therapies,” the email said, adding that newly initiated stem cell research applications at the center include Parkinson’s disease and thrombocytopenia, a lack of platelets in the blood.

Another view of stem cell research

The Japanese study and the second study describing the blinding of three patients stand as “polar-opposite approaches to testing new therapies for age-related macular degeneration (AMD), which is a leading cause of blindness among elderly patients,” wrote Dr. George Q. Daley, dean of the faculty of medicine at Harvard Medical School, in an editorial published in the New England Journal of Medicine.

The American story, like the Japanese story, begins with patients slowly losing their sight as a result of macular degeneration – in this case, three women ages 72 to 88, two of whom had the “dry” form.

Each patient paid $5,000 for the procedure at an unnamed clinic in Florida, the authors noted. Some of the patients, including two of the three women described in the paper, learned of the so-called clinical trial on ClinicalTrials.gov, a registry database run by the US National Library of Medicine. However, the consent form and other written materials did not mention a trial.

The procedure took less than an hour and began with a standard blood draw and the removal of fat cells from each patient’s abdomen. To obtain stem cells, the fat tissue was processed with enzymes, while platelet-dense plasma was isolated from the blood. The stem cells were mixed with the plasma and injected into both eyes.

Complications may have been caused by contamination during stem cell preparation, or the stem cells might have changed into myofibroblasts, a type of cell associated with scarring, after injection, the authors wrote.

Before the surgery, the women’s vision ranged from 20/30 to 20/200. After treatment and complications, the patients were referred in June 2015 to two university-based ophthalmology practices, including the University of Miami, where lead author Dr. Ajay E. Kuriyan was practicing.