Last week, a patient with blurry vision in his right eye walked into a doctor’s office and became the first person to receive reprogrammed stem cells from a donor to treat his age-related macular degeneration.
The patient – a Japanese man in his 60s – is not alone, as four other patients have been approved for the procedure by Japan's health ministry. The first medical case was reported on March 28 by Nature.
In a one-hour operation by surgeon Yasuo Kurimoto, the patient received skin cells from a human donor at Kobe City Medical Center General Hospital. The donor’s skin cells were reverse engineered into induced pluripotent stem (iPS) cells. These cells are often seen as a game-changer in the world of regenerative medicine as they have the ability to become almost any type of cell in the body.
In this case, the iPS cells were turned into retinal cells, which were then implanted into the retina of the patient, who has age-related macular degeneration. It is hoped the procedure will stop the progression of the disease, which can lead to blindness. The transplant is not being touted as a cure for the condition, merely a prevention method from further damage.
During the procedure, the surgical team injected 50 microliters of liquid containing 250,000 retinal cells into the patient’s eye, according to the Japan Times. The real test, however, will be the next phase of monitoring.
What sets this transplant apart is also what makes the recovery process precarious. Doctors will need to keep a careful watch on the patient, as iPS cells from a donor are not a genetic match and could cause an immune rejection.
At this point, you might remember a similar case in 2014 with a Japanese woman at the same hospital. She also received retinal cells derived from iPS cells, however hers were taken from her own skin, not a donor's.
"A key challenge in this case is to control rejection," said Riken researcher Masayo Takahashi to the Japan Times. "We need to carefully continue treatment."
In an update, the team said the Japanese woman was doing well and her vision had not declined. They decided to change track and use donor cells for this study because it holds a more viable future for such transplants.
It's hoped, if all goes well here, that researchers can create a bank of donor stem cells. Such a future would cut down on costs and reduce wait times, as cultivating one’s own cells can take several months. However, there's still much to be done.
After the procedure, Takahashi told a press conference that the surgery went well. They will continue to monitor the situation and provide further updates in the future.