KYOTO – Kyoto University said Friday it has conducted the world’s first transplant of induced pluripotent stem cells to treat Parkinson’s disease.
Nerve cells created from the artificially derived stem cells, known as iPS cells, were transplanted into the brain of a patient in his 50s in October in a treatment researchers hope to develop into a method that can be covered under Japan’s health insurance system.
“By also cooperating with companies, we want to develop a mass production system that enables us to deliver nerve cells derived from iPS cells to all over the world,” said Jun Takahashi, a professor at the university’s Center for iPS Cell Research and Application who led the research team, at a news conference.
Parkinson’s disease reduces dopamine-producing neurons in the brain and results in tremors in the hands and feet and stiffness in the body. While there are treatments to relieve the symptoms, there is currently no cure for the disease.
In Japan, an estimated 160,000 people suffer from the progressive neurological disorder. Many patients develop symptoms when in their 50s or older, and the number of patients is rising due to the graying of society.
The clinical trial was carried out by the research center and Kyoto University Hospital, with doctors verifying the transplant’s safety and effectiveness.
Shinya Yamanaka, who heads the center, won the Nobel Prize in physiology or medicine in 2012 for discovering iPS cells, which can grow into any type of body tissue and are seen as a promising tool for regenerative medicine and drug development.
According to the treatment plan, the nerve cells transplanted into the patient’s brain were created using iPS cells derived from people who had types of immunity that made them less prone to rejecting transplants.
The nerve cells are expected to supplement dopamine-emitting neurons.
During a course of treatment that will be monitored for two years, immune suppressor drugs will be injected to reduce the possibility of rejections.
The transplant performed last month is aimed mainly at verifying the safety of such a therapy, by checking whether any tumors develop in the brain. So far, no hemorrhages within the brain or other harmful symptoms have been found, according to the university.
At the news conference at the hospital, Takayuki Kikuchi, a surgeon, elaborated on the process of the three-hour operation he performed.
“We made a hole in the frontal part of the left side of the head and transplanted some 2.4 million cells,” he said, adding that the patient smiled with relief after the operation.
The study will involve seven patients in their 50s and 60s, who fulfilled the criteria of having received drug treatments without effective results and having suffered from Parkinson’s disease for more than five years.
“Having heard the news of the first trial, I feel the research is steadily moving forward step by step. We are all looking forward to hearing a positive outcome,” said Hisao Hiramine, a 70-year-old who suffers from the disease and chairs a Tokyo association of patients and their families.
Asked about his eventual goal, Kyoto University’s Takahashi said, “The best scenario is to see patients improve to the extent they do not have to take any medicine.”
He added: “For surgeons, the result is all that matters.”
Outside Japan, nerve cells from aborted fetuses have been transplanted into patients’ brains in clinical research conducted since the 1980s. Although the method proved effective to a certain extent, it entailed ethical problems and side effects in which patients’ bodies moved unintentionally.
The iPS cells used in this study are of high quality, for clinical use, and could also be prepared in a large volume.
The application of iPS cells to health treatment follows the world’s first clinical study by the Japanese government-backed Riken institute to transplant retina cells grown from stem cells to treat patients suffering from serious eye problems.
Among other clinical trials related to regenerative medicine, Osaka University is planning to transplant heart muscle cell sheets derived from iPS cells into the hearts of patients who are suffering from serious heart failure.
Another research team at Kyoto University is expected to begin a blood transfusion test using platelets created from the stem cells in order to treat patients with aplastic anemia.
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