A simple blood test detecting a nerve protein, neurofilament light chain, could be a new tool for monitoring flare-ups in patients suffering relapsing-remitting multiple sclerosis (MS).
The research, published in Neurology, Neuroimmunology & Neuroinflammation, followed 85 patients with relapsing-remitting MS, a form of the disease marked by worsening of symptoms followed by periods of remission.
During the initial 6 months of the trial, patients were not given any disease altering therapy. Over the next 18 months, they were treated with interferon-beta 1a, a cytokine that has been seen to reduce frequency of pain flare-ups as well of formation of brain lesions. Patients had MRI scans monthly throughout the first 9 months of the trial, and subsequently after year one and year two, with blood samples also being taken at these stages.
The team discovered that levels of neurofilament light chain, which is a nerve cell component found in blood and spinal fluid when nerve cells die, were higher when the MRI scan indicated new T1 and T2 lesions – areas of MS-induced brain damage. Patients with new T1 lesions exhibited 37.3 picograms per millilitre (pg/ml), in contrast with levels of 28 pg/ml for those without new T1 lesions. Similar levels were also observed for T2 lesions.
As little as a 10 pg/ml increase in the protein was found to correlate with a 48% increased risk of developing a new T1 lesion, with a 62% increased risk for T2 lesions. However, levels of neurofilament light chain were reduced following treatment with interferon-beta 1a.
The study demonstrates some limitations in that the majority of MS patients would not normally have access to such frequent MRI scanning, and while most exhibited new lesions, not all patients suffered relapses. However, long-term research into the use of blood tests as a monitoring tool show promise, as summarized by lead author Kristin Varhaug (University of Bergen, Norway): “Blood tests for this nerve protein may be an effective way to monitor disease activity and how well the treatment is working.”
Sources: Kristin N. Varhaug, Christian Barro, Kjetil Bjørnevik et al. Neurofilament light chain predicts disease activity in relapsing-remitting MS. Neurol., Neuroimmunol. & Neuroinflam. doi:10.1212/NXI.0000000000000422 (2017) (Epub ahead of print); http://nn.neurology.org/content/5/1/e422