Cell-free circulating mtDNA identifies Parkinson's disease

Dec. 10, 2015

(HealthDay)—Cell-free circulating mitochondrial DNA (ccf-mtDNA) from cerebrospinal fluid (CSF) is reduced in patients with Parkinson's disease (PD), according to research published in the December issue of the Annals of Neurology.

Angela Pyle, Ph.D., from the University of Newcastle Upon Tyne in the United Kingdom, and colleagues examined whether ccf-mtDNA was an early indicator of PD pathology. Fifty-six CSF samples from patients with PD were selected with 10 age-matched asymptomatic control CSF samples.

The researchers observed a significant reduction in ccf-mtDNA in PD cases versus controls, when analyzing two mtDNA targets: MTND1 and MTDN4 copy number. In receiver operating characteristic curve analysis, MTND1- and MTND4-calculated ccf-mtDNA strongly predicted PD status (area under curve, 0.81 and 0.84, respectively). There was no significant correlation for ccf-mtDNA with CSF-tau, -phosphorylated tau, and -α-synuclein.

"Given the severity of the reduction in CSF ccf-mtDNA in PD, and supported by both subsequent measurement and remarkably similar data observed in Alzheimer's Disease, we conclude that ccf-mtDNA is a viable biomarker for the early detection of neurodegenerative disease," the authors write.

 Explore further: Study examines immunotherapy and cerebrospinal fluid biomarkers in patients with Alzheimer's The identification of cell-free circulating mitochondrial DNA (ccf-mtDNA) in early-stage Alzheimer's disease (AD) raised the possibility that the same neurodegenerative effect could be observed in Parkinson's disease (PD). Here, and for the first time, we investigated the role of ccf-mtDNA in PD, identifying a significant reduction of ccf-mtDNA in PD patient cerebrospinal fluid (CSF) when compared to controls. Our data demonstrates that CSF ccf-mtDNA is not only a powerful biomarker for PD, but, given that the effect is also observed in AD, is likely a biomarker for neurodegeneration. Ann Neurol 2015;78:1000–1004

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