Risi, Barbara

Abstract KIF5A (Kinesin family member 5A) is a motor protein that functions as a key component of the axonal transport machinery. Variants in KIF5A are linked to several neurodegenerative diseases, mainly spastic paraplegia type 10 (SPG10), Charcot-Marie-Tooth disease type 2 (CMT2), and amyotrophic lateral sclerosis (ALS). These diseases share motor neuron involvement but vary significantly in clinical presentation, severity, and progression. KIF5A variants are mainly categorized into N-terminal variants associated with SPG10/CMT2 and C-terminal variants linked to ALS. This study utilized a novel multiplex NULISA targeted platform to analyze plasma proteome from KIF5A -linked SPG10, ALS patients and compared to healthy controls. Our results revealed distinct proteomic signatures, with significant alterations in proteins related to synaptic function, and inflammation. Notably, neurofilament light polypeptide, a biomarker for neurodegenerative diseases, was elevated in KIF5A ALS but not in SPG10 patients. Moreover, these findings can now be taken forward to gain mechanistic understanding of axonopathies linking to N- vs C-terminal KIF5A variants affecting both central and peripheral nervous systems.

Abstract Background Recent findings indicated that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-related neurological manifestations involve cytokine release syndrome along with endothelial activation, blood brain barrier dysfunction, and immune-mediated mechanisms. Very few studies have fully investigated the cerebrospinal fluid (CSF) correlates of SARS-CoV-2 encephalitis. Methods Patients with polymerase chain reaction (PCR)-confirmed SARS-CoV-2 infection and encephalitis (COV-Enc), encephalitis without SARS-CoV-2 infection (ENC), and healthy controls (HC) underwent an extended panel of CSF neuronal (neurofilament light chain [NfL], T-tau), glial (glial fibrillary acidic protein [GFAP], soluble triggering receptor expressed on myeloid cells 2 [sTREM2], chitinase-3-like protein 1 [YKL-40]) and inflammatory biomarkers (interleukin [IL]-1β, IL-6, Il-8, tumor necrosis factor [TNF] α, CXCL-13, and β2-microglobulin). Results Thirteen COV-Enc, 21 ENC, and 18 HC entered the study. In COV-Enc cases, CSF was negative for SARS-CoV-2 real-time PCR but exhibited increased IL-8 levels independently from presence of pleocytosis/hyperproteinorracchia. COV-Enc patients showed increased IL-6, TNF- α, and β2-microglobulin and glial markers (GFAP, sTREM2, YKL-40) levels similar to ENC but normal CXCL13 levels. Neuronal markers NfL and T-tau were abnormal only in severe cases. Conclusions SARS-CoV-2-related encephalitis were associated with prominent glial activation and neuroinflammatory markers, whereas neuronal markers were increased in severe cases only. The pattern of CSF alterations suggested a cytokine-release syndrome as the main inflammatory mechanism of SARS-CoV-2-related encephalitis.