OSAKA – A Japanese team reported Thursday that five patients with a severe eye disease were doing well after they received in 2017 the world’s first transplant surgeries using induced pluripotent stem cells, known as iPS cells, from donors.
As part of a clinical research program, the patients received the transplants of artificially grown retinal cells made from donor iPS cells as a treatment for wet-type age-related macular degeneration, which can often lead to blindness.
The first transplant was performed in March 2017. In the surgeries, a fluid containing retinal cells was injected into the patients’ eyes.
The transplanted retinal cells became firmly fixed, and one patient whose body rejected the transplant to a mild extent was able to overcome it by taking medications, according to project leader Masayo Takahashi, a researcher at the government-backed Riken institute.
Of the five, four have maintained their level of visual acuity after the operations, while one experienced an improvement in their vision.
“We think we were able to ensure the safety (of the treatment). We’d like to begin new clinical trials to find out for what type of symptoms the treatment would be highly effective,” Takahashi said in the first detailed report on the patients’ post-surgery recovery.
The first patient, a man living in Hyogo Prefecture, experienced increased levels of fluid in his retina due to the rejection, but the administration of steroids contained it, according to the team, which involved Riken and the Kobe City Medical Center General Hospital.
The trials used iPS cells stocked at Kyoto University designed to lower the risk of rejection. Shinya Yamanaka, one of two people awarded a 2012 Nobel Prize in physiology or medicine for the discovery that cells could be reprogrammed into iPS cells, heads iPS research at the university and is working to adapt the treatment for many types of illnesses and injuries.
Compared with using iPS cells taken from patients themselves, using stocked donor cells can cut down the cost and time to culture cells for transplants, according to the team.
Of the five, the second patient suffered a swollen retina after undergoing the transplant, the team said in January last year. But the group concluded it was part of surgical complications rather than a rejection of transplanted iPS cells.
In 2014, Takahashi and others succeeded for the first time in the world in transplanting into a woman retinal cells grown from her own iPS cells.