Japanese researchers said on Friday they have transplanted so-called "iPS" stem cells into the brain of a Parkinson's disease patient, the world's first such test.
The team at the Kyoto University injects 2.4 million of them multipotent cells, capable of giving any kind of cell, on its left side brain, during a three-hour operation last month.
The man, at the age of fifty, was well tolerated and will now be under surveillance for two years, Kyoto University said in a statement.
If there is no problem in the next six months, researchers will implant 2.4 million more cells, this time on the right side of the patient's brain.
These iPS cells from healthy donors are believed to grow in dopamine-producing neurons, a neurotransmitter involved in motor control.
Kyoto University announced in July that it owns this clinical trial with seven participants aged 50 to 69.
"I salute the patients for their courageous and decisive participation"said Professor Jun Takahashi, quoted on Friday by NHK public broadcaster.
The Parkinson's disease is characterized by degeneration from those neurons and results in the progressive deterioration of symptoms such as tremors, limb stiffness and decreased body movement.
It affects more than 10 million people worldwide, according to the US Parkinson's Disease Foundation. Currently available treatments "improve the symptoms without slowing down progress of the disease"says this foundation.
This new research aims to reduce harm.
This test follows an experiment carried out on monkeys with stem cells of human origin that made it possible to improve the ability of Parkinson's primary mammals to move, according to a study published at the end of August 2017 in the journal Nature. Survival of the vaccinated cells, injected into the primate brain, was observed for two years without tumor appearance.
The induced pluripotent stem cells (iPS for induced pluripotent stem cells) are adult cells that return to the near-fetal state by re-expressing four genes (normally inactive in adult cells). this genetic manipulation gives them the ability to produce any kind of cells (pluripotency), depending on where they are transplanted into the body.
The use of iPS cells does not create fundamental moral problems, as opposed to stem cells derived from human embryos.