London, Apr 7 : A new study has revealed that fetal cells transplanted into brain to treat Parkinson's disease can actually worsen the condition.
Jeffrey H. Kordower, PhD, lead author and a neuroscientist at Rush University Medical Centre, said that their findings suggest that the Parkinson's can affect the implanted cells in a similar way that it affects host dopamine neurons in the substantia nigra of the brain.
"These findings give us a bit of pause for the value of cell replacement strategy for Parkinson's disease," Nature quoted Kordower, as saying.
"We still need to vigorously investigate this approach among the full armament of surgically-delivered Parkinson's disease therapies. While it is not clear to us whether the same fate would befall stem cell grafts, the next generation of cell replacement procedures, this study does suggest that grafted cells can be affected by the disease process," he added.
In the article, the researchers mentioned a case of a woman who had a 22-year history of Parkinson's disease and had undergone transplantation in 1993.
Though the transplantation showed improvements in disease symptoms as measured by the Unified Parkinson Disease Rating Scale (UPDRS) and lowered the doses of anti-parkinsonian medications, but her symptoms worsened in 2004. She died in 2007.
However, she was known to be the longest surviving individual among the study participants after transplantation.
"The findings also suggest that there may be either a pathogenic factor in the brain that affects dopamine producing neurons or a pathological process that can spread from one cellular system to another," said Kordower.
"These findings have striking implications for understanding what causes PD and the potential for cell replacement strategies to reverse the motor symptoms," he added.
The report appears in the April 6 issue of Nature Medicine.