Recently, there has been new evidence discovered in support that Neurofilament Light (NfL) protein can track neurodegeneration and disease progress within patients suffering from a wide variety of neurodegenerative disorders. NfL is a protein that is released into the cerebrospinal fluid (CSF) once a neuron dies. Scientists, led by Bob Olsson and Erik Portelius, University of Gothenburg, Sweden, found high levels of NfL in the cerebrospinal fluid of people suffering with these disorders where the more severe a person’s disease, the higher his or her CSF NfL . Olsson and colleagues had previously reported higher CSF NfL among 3356 people in Sweden who had various kinds of dementia.
The current study, led by Nicholas Cullen at University of Pennsylvania, Philadelphia, and others, examined 838 patients who had been treated at UPenn’s six different neurodegenerative disease centers beginning in 1996. Baseline CSF was sampled and all patients had undergone follow up cognitive testing for one to 18 years. In all patients, above average levels of NfL were found in the sampled CSF. Mini mental state examinations (MMSE) were conducted and showed that patients with higher NfL levels scored worse on the cognitive tests. This also meant that MMSE scores declined faster on subsequent cognitive tests in these same patients with higher levels of NfL.
“The study demonstrates that NfL is a reliable biomarker for neurodegeneration” said co-author Henrik Zetterberg, also from the University of Gothenburg. Recently, Zetterburg and his colleagues discovered that NfL in plasma mirrors levels in CSF, which means that scientists can likely get the same NfL results from a simple blood test. By easing the procedure, this could potentially increase enrollment in future studies and also allow for longer studies to be conducted that track changes in NfL over longer periods of time.
NfL also has the potential to help improve clinical trials and hopefully allow researchers to monitor whether drugs could slow neurodegeneration within patients. For example, in multiple sclerosis, CSF NfL levels fall in patients that have been treated with natalizumab. This means that NfL could potentially help predict when a person’s cognition will decline.
“Future autopsy work examining whether CSF NfL levels correlate with the degree of neuronal loss within each disorder will greatly improve our understanding of what these changes truly represent” wrote William Hu, Emory University, Atlanta.