Neuro-inflammatory biomarkers in ALS imply glial pathology

CSF chitinase (Chit-1) and phosphorylated neurofilament heavy chain levels are both raised in patients with amyotrophic lateral sclerosis (ALS), tweaking interest in these proteins as potential disease biomarkers,1 2 for example, in selecting patients for clinical trials. Here, Vu et al 3 show that elevated CSF chitinase levels delineate a subset of fast-progressing ALS. However, although these abnormalities are markers of active disease, they do not change over time and, like other potential biomarkers, they are not specific for ALS. Unlike insects, chitin is not a constituent of mammalian neural or other …