CSF parvalbumin levels reflect interneuron loss linked with cortical pathology in multiple sclerosis

Abstract Introduction and methods In order to verify whether parvalbumin (PVALB), a protein specifically expressed by GABAergic interneurons, could be a MS‐specific marker of grey matter neurodegeneration, we performed neuropathology/molecular analysis of PVALB expression in motor cortex of 40 post‐mortem progressive MS cases, with/without meningeal inflammation, and 10 control cases, in combination with cerebrospinal fluid (CSF) assessment. Analysis of CSF PVALB and neurofilaments (Nf‐L) levels combined with physical/cognitive/3TMRI assessment was performed in 110 naïve MS patients and in 32 controls at time of diagnosis. Results PVALB gene expression was downregulated in MS (fold change = 3.7 ± 1.2, P