Parkinson's Disease - Promising Biomarker Research

When boxer Mohammed Ali described his own fighting style as “float like a butterfly and sting like a bee” his fans thrilled while his opponents seethed. Little, then, did the world realize that the invincible heavy weight champ would soon succumb to one of the worst degenerating neurological diseases.

Parkinson’s disease

Parkinson’s disease (PD) is a degenerative disease that affects the neurons of the brain that control muscle movements. In healthy people, these neurons produce dopamine, a neuro- transmitter, responsible for the smooth co-ordinated movements of the body. In PD patients, these neurons die, which in turn leads to the debilitating disease.

Although there is a lot of research being carried out in the field of Parkinson’s disease, no reliable, validated, cheap and simple biomarkers have been identified to help in the diagnosis, treatments or in monitoring disease progression.

A novel initiative-PPMI

Parkinson's Progression Markers Initiative (PPMI), triggered by the Michael J Fox Foundation is a public-private initiative that aims to identify markers - clinical, imaging, and biological – to identify PD and to monitor its progression. Given its paucity, this is indeed welcome news.

PPMI is modelled on the Alzheimer's Disease Neuroimaging Initiative (ADNI) and is the first international prospective observational study that has been designed to validate markers of disease progression in PD patients.

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It hopes to involve 20 centres in the USA and Europe. The endeavor is expected to last for 5 years and will cost US$40 million.

The experiments are to be carried out on--

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• 400 newly diagnosed PD patients who have are not yet on medication and who also display evidences of dopamine transporter loss on imaging studies
• 200 healthy age-matched controls.

Parameters for the study

The most promising of the candidates will be tested using the following –

• Advanced brain imaging techniques
• Blood, urine, CSF tests
• DNA sampling

The following analysis will also be carried out on them -

• Motor skill evaluation
• Neuropsychiatric studies
• Cognitive assessments

Initially the study will emphasize on the detection of fluid markers such as α-synuclein, DJ-1, amyloid β, and Tau protein marker in Cerebro Spinal Fluid and urate in blood.

PPMI -Other Highlights

It is heartening to know that all of PPMI’s research data and biological specimens will be stored in a central repository and will be commonly available to the research community. The database generated will also help to further fuel this area of research.

It is hoped that the PPMI’s study will lead to –

• Identification and development of markers that will identify individuals at risk (screening)

• Role of markers in disease progression and drug response

• Co-relation studies based on the role of different markers and their role in screening

• Identifying subgroup of patients with different response to drugs

• Pharmacodynamic biomarkers could help to determine if a drug is reaching its intended target of action

Hurdles

• One major obstacle that the scientists are facing is that the data collection, specimen collection, their processing and storage methods differ from center to center.

• Standardization appears a possibility for CSF and blood biomarker data, but not feasible for imaging data that are gathered with different devices from various sources. Moreover imaging data can frequently become outdated too

• Bio markers also require to be useful, cheap and user–friendly

• Large number of samples are required to identify sensitive bio- markers and also to identify different forms of the disease.

Despite the several hurdles it is enlightening to know that this collaborative effort will encourage traditional bio marker-based research besides lending promise to PD patients with regard to their early detection and patient-specific treatment.

Lets hope that another long wait is over!

Source-Medindia