PT - JOURNAL ARTICLE AU - Pinteac, Rucsanda AU - Montalban, Xavier AU - Comabella, Manuel TI - Chitinases and chitinase-like proteins as biomarkers in neurologic disorders AID - 10.1212/NXI.0000000000000921 DP - 2021 Jan 01 TA - Neurology - Neuroimmunology Neuroinflammation PG - e921 VI - 8 IP - 1 4099 - http://nn.neurology.org/content/8/1/e921.short 4100 - http://nn.neurology.org/content/8/1/e921.full SO - Neurol Neuroimmunol Neuroinflamm2021 Jan 01; 8 AB - Chitinases are hydrolytic enzymes widely distributed in nature. Despite their physiologic and pathophysiologic roles are not well understood, chitinases are emerging as biomarkers in a broad range of neurologic disorders, where in many cases, protein levels measured in the CSF have been shown to correlate with disease activity and progression. In this review, we will summarize the structural features of human chitinases and chitinase-like proteins and their potential physiologic and pathologic functions in the CNS. We will also review existing evidence for the role of chitinases and chitinase-like proteins as diagnostic and prognostic biomarkers in inflammatory, neurodegenerative diseases, and psychiatric disorders. Finally, we will comment on future perspectives of chitinase studies in neurologic conditions.Aβ=β-amyloid; AMCase=acidic mammalian chitinase; CHI3L1=chitinase-3-like 1; CHI3L2=chitinase-3-like 2; CHIT1=chitotriosidase; CIS=clinically isolated syndrome; CJD=Creutzfeldt-Jakob disease; CLP=chitinase-like protein; CRTH2=prostaglandin D2 receptor 2; EAE=experimental autoimmune encephalomyelitis; Erk=extracellular signal-regulated kinase; FAK=focal adhesion kinase; FTD=frontotemporal dementia; GH18=18 glycosyl hydrolase; IL-13Rα2=interleukin-13 receptor α2; IFN=interferon; MAPK=mitogen-activated protein kinase; MCI=mild cognitive impairment; NF-κB=nuclear factor kappa B; OVGP1=oviductin-specific glycoprotein; PCS=post-concussion syndrome; PD=Parkinson disease; PPMS=primary progressive MS; RRMS=relapsing-remitting MS; SI-CLP=stabilin-1–interacting CLP; SPMS=secondary progressive MS; TGF-β=transforming growth factor β; Th2=T-helper cell type 2; TIM=triosephosphate isomerase; TMEM219=transmembrane protein 219; TNFα=tumor necrosis factor alpha