Scientists have identified a panel of 13 blood biomarkers significantly associated with Parkinson’s disease, offering a potential pathway to earlier diagnosis and improved monitoring of the neurodegenerative disorder. The research, published in November 2024, builds on the growing understanding of biomarkers – measurable indicators of biological states – in Parkinson’s, a disease currently diagnosed primarily through clinical observation of motor symptoms and response to medication.
Currently, diagnosis relies heavily on neurological exams, symptom history, and a patient’s response to dopamine therapies, a process that can take considerable time. The absence of a definitive diagnostic test means that by the time symptoms manifest, significant brain damage may already have occurred. Researchers are now focusing on identifying biomarkers that can detect the disease in its earliest stages, potentially years before motor symptoms appear.
The study, which initially screened 67 biomarkers including both blood and urine samples, highlighted three novel markers – phosphate, the ratio of aspartate aminotransferase (AST) to alanine aminotransferase (ALT), and immature reticulocyte fraction (IRF) – as particularly promising. These findings corroborate existing research identifying other biomarkers, including insulin-like growth factor 1 (IGF-1) and C-reactive protein (CRP), as potentially linked to Parkinson’s risk and progression. Genetic analysis revealed significant overlaps between the genetic loci of IRF, CRP, and IGF-1 and those associated with Parkinson’s disease, specifically at locations including MAPT, SETD1A, HLA-DRB1, and HLA-DQA1.
Although cerebrospinal fluid analysis, specifically the alpha-synuclein seed amplification assay (SAA) which detects misfolded alpha-synuclein, and skin biopsies using the Syn-One Test to detect phosphorylated alpha-synuclein, can support diagnosis, these tests are currently limited to research settings or specialized clinical cases. The development of accessible, blood-based biomarker tests represents a significant step towards widespread early detection. Researchers are also exploring less invasive methods for biomarker testing, aiming to make diagnosis more accessible to a broader population.
The identified biomarkers are not yet ready for clinical application. Further research is needed to validate these findings in larger, more diverse populations and to determine the optimal combination of biomarkers for accurate diagnosis and disease monitoring. Mendelian randomization analysis suggests potential causal links between IGF-1, CRP, and Parkinson’s disease, but the precise mechanisms underlying these associations remain under investigation.
The Parkinson’s Foundation notes that biomarkers, like cholesterol as an indicator of heart disease, provide information about a person’s health. The current focus is on utilizing biomarkers to facilitate earlier diagnosis, track disease progression, and enhance clinical trials. However, standard diagnosis continues to depend on neurological evaluations, symptom assessment, and response to dopamine-based treatments.
