National Institutes of Health Researchers Adapt Test for Early Diagnosis of Parkinson's Disease and Dementia with Lewy Bodies
Acta Neuropathologica Communications published a paper by researchers at the National Institutes of Health (NIH) (Groveman BR, Orrù CD, and Hughson AG, et al. Acta Neuropathol Comm. 2018;6:published online Feb 9) showing that an assay, α-synuclein real time quaking-induced conversion (αSyn RT-QuIC), for the pathogenic disease-associated forms of a-synuclein is sensitive, specific and practical for assessing the presence of those proteins in cerebrospinal fluid. Those specific forms of a-synuclein form abnormal protein aggregates in the brain in both Parkinson’s disease and dementia with Lewy bodies. Although 2 other assays for these proteins are already available, the αSyn RT-QuIC is novel in that results are available within 1 to 2 days versus the 5 to 13 days that it takes to obtain results with other assays.
The authors performed a blinded analysis of cerebrospinal fluid from 29 patients with synucleinopathy [12 Parkinson’s and 17 dementia with Lewy bodies] and 31 non-synucleinopathy controls, including 16 Alzheimer’s cases using the αSyn RT-QuIC and showed a 93% diagnostic sensitivity and 100% specificity for the assay They were also able to use end-point dilution analysis to confirm that α-synuclein seeding activity is present in cerebrospinal fluid. Further the authors showed that this assay can detect and be used to quantify the amount of α-synuclein in cerebrospinal fluid, even in the early symptomatic stages of synucleinopathies Parkinson’s disease and dementia with Lewy bodies.
The ability to detect biomarkers for syncleinopathies is expected to aid in diagnosis of patients with Parkinson’s disease and dementia with Lewy bodies, development of new therapeutics, and identification of subjects for clinical trials diagnostics. In their discussion, the authors note that, “early detection of αSynD is particularly helpful, firstly, because the accuracy of diagnoses based on other clinical indices is poorest in the earlier phases of disease, and, secondly, because the earlier the diagnosis, the earlier that any appropriately targeted therapies can be initiated before further tissue damage is done.”