Biomarker in Blood Tests May Help Distinguish Parkinson’s from Similar Diseases

A biomarker usually measured in the cerebrospinal fluid (CSF) and used to differentiate Parkinson’s disease (PD) from similar diseases, has been found to have high diagnostic value when analyzing blood samples. These findings suggest that diagnosis can be obtained more easily without sacrificing accuracy.

The study “A biomarker for differential diagnosis of parkinsonian disorder” was published in the Neurology journal.

PD and other types of disease, collectively known as atypical parkinsonian disorders (APDs), exhibit overlapping symptoms, which hinder accurate diagnoses. APDs include multiple system atrophy (MSA), progressive supranuclear palsy (PSP), and corticobasal degeneration (CBD).

The neurofilament light chain (NfL) protein is found in the CSF and was reported as a promising marker for APD.

“Our group and others have previously shown that the CSF concentration of NfL is increased in APD but not in PD and that NfL in CSF can discriminate between PD and APD with a high degree of diagnostic accuracy,” researchers wrote.

However, collecting CSF is a delicate procedure that requires appropriate facilities (not always found in primary care settings) and the procedure (lumbar puncture) leaves patients apprehensive.

Now, researchers used an ultra-sensitive single molecule array method known as Simoa, a technology by Quanterix Corporation, to measure the levels of NfL in blood samples. They tested if detecting NfL in blood samples could distinguish PD from APD in patients.

The team analyzed blood samples from three independent prospective cohorts: the Lund (n = 278) and London (n = 117) groups, which included healthy control subjects and patients with PD, progressive supranuclear palsy (PSP), corticobasal syndrome (CBS), and multiple system atrophy (MSA), as well as an early disease group (n = 109) of patients with PD, PSP, MSA, or CBS with disease duration less than than three years.

The team found strong correlations between the levels of NfL present in the blood with the concentrations in CSF. Moreover, the blood NfL levels were increased in all APD groups when compared to PD patients and healthy control subjects. In the Lund group, blood NfL could accurately distinguish PD from APD.

Overall, “our findings are exciting because when Parkinson’s or an atypical parkinsonism disorder is suspected, one simple blood test will help a physician to give their patient a more accurate diagnosis,” said Oskar Hansson, MD, PhD, the study’s first author, in a press release. Lund also is an associate professor at Lund University in Sweden.

“These atypical parkinsonism disorders are rare, but they generally progress much faster and are more likely to be the cause of death than Parkinson’s disease, so it’s important for patients and their families to receive the best care possible and to plan for their future needs,” Lund said.