|LETTER TO THE EDITOR
|Year : 2020 | Volume
| Issue : 2 | Page : 121-122
An ongoing search for “biomarkers in Parkinson’s disease”
Shweta Pandey, Ravindra K Garg
Department of Neurology, King George’s Medical University, Lucknow UP, India
|Date of Submission||27-Jan-2020|
|Date of Decision||27-Jan-2020|
|Date of Acceptance||18-Apr-2020|
|Date of Web Publication||28-Jul-2020|
Dr. Shweta Pandey
Associate Professor, Department of Neurology King George’s Medical University, Lucknow UP.
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Pandey S, Garg RK. An ongoing search for “biomarkers in Parkinson’s disease”. Ann Mov Disord 2020;3:121-2
We read a recently published article by Shree et al. Authors describe serum apolipoprotein A1 (Apo A1) and DJ-1 as early biomarkers in Parkinson’s disease (PD). Development of biomarkers has become important in early diagnosis of PD because it is a common neurodegenerative disorder and an early neuroprotective strategy may halt progression of the disease. PD is considered a motor disorder and treatment also is focused on dealing with these symptoms. However, for the last two decades there is more emphasis on early recognition of nonmotor symptoms (NMSs) and its treatment for better outcomes in PD. The NMSs become important in the sense that some of them (e.g., rapid eye movement sleep behavior disorder [RBD], constipation, anosmia, depression and anxiety, and visual dysfunction) are present almost 5–10 years before the onset of disease and can predict development of PD overtime. These clinical features can very well be used as biomarkers but the problem arises with their overlap with other neurogenerative disorders, lack of objectivity, and reproducibility. Therefore, a set of clinical, neuroimaging, serum/cerebrospinal fluid (CSF) inflammatory, metabolic, aggregates, and genetic biomarkers are being explored to develop a comprehensive set of biomarkers for early and accurate diagnosis, prognosis, prediction of progression, cognitive impairment, and response to intervention in patients with PD. Early detection of patient with PD or risk population can be a candidate for neuroprotective intervention. The study focuses on importance of serum DJ-1 and Apo A1 levels similar to other studies but the level of these biomarkers change with different stages of PD and the correlation with prodromal nonmotor features is also variable. Apolipoproteins along with α-synuclein maintain cell membrane integrity, especially Apo-,D, Apo-J, Apo-I, and Apo-E, play an important role in lipid homeostasis in brain cells and some of their isoforms prevent neurodegeneration via antioxidant, antiapoptotic, and antiaggregatory activity. Levels of apolipoproteins are affected in other neurodegenerative disorders as well such as Alzheimer’s disease (AD) but specificity for PD may be further increased by an assessment of different isoforms of apolipoproteins considering the hypothesis that some of them may be purely affected in PD. Diagnostic use of cerebrospinal-fluid DJ-1 is being explored but nonreliable because of fluctuating levels at different stages, poor reproducibility, and overlap with other neurodegenerative disorders. Plasma levels are much more unpredictable because of the higher concentration of DJ-1 in erythrocytes. Pathological DJ-1 protein not only leads synuclein aggregation but has been linked to hyperphosphorylation of tau protein. Differentiating PD from other neurodegenerative disorders still need techniques to assess various oxidized and non-oxidized forms of DJ-1 in plasma/erythrocytes which is a step ahead in confirming its role as a diagnostic and prognostic marker. Cerebrospinal-fluid and plasma biomarkers involved in pathophysiology of PD such as synuclein aggregates, β-amyloid, tau, lysosomal enzymes, and neurofilament chain which in combination with other neuroimaging and genetic biomarkers could help in better understanding the disease progression and response to treatment. However, findings in this study enhance the role of early biomarkers in PD and warrant further research in this area.
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Conflicts of interest
There are no conflicts of interest.
| References|| |
Shree R, Mulagala M, Mehta S, Sood A, Modi M, Goyal MK, et al
. Role of DJ-1 and Apo A1 as biomarkers in Parkinson’s disease: An observational case-control study. Ann Mov Disord 2019;2:109. [Full text]
Swanson CR, Berlyand Y, Xie SX, Alcalay RN, Chahine LM, Chen-Plotkin AS Plasma apolipoprotein A1 associates with age at onset and motor severity in early Parkinson’s disease patients. Mov Disord 2015;30:1648-56.
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