Work

Plasma glial fibrillary acidic protein and neurofilament light chain are measures of disease severity in semantic variant primary progressive aphasia

Year: 2020

Type: article

Abstract: Semantic variant primary progressive aphasia (svPPA) is a neurodegenerative disorder characterised by loss of conceptual knowledge, commonly presenting with word-finding difficulties, impaired single word comprehension and focal atrophy of the temporal lobe.1 It is a subtype of frontotemporal dementia (FTD) and usually associated with TDP-43 type C pathology. While much progress has been made in the last 20 years in understanding the cognitive and biological nature of svPPA, there have been limited studies of fluid biomarkers.2 In this study, we investigated the role of plasma glial fibrillary acidic protein (GFAP) and neurofilament light chain (NfL) as biomarkers for astroglial activation and neurodegeneration in svPPA, as well as their association with disease severity in svPPA. ### Participants Plasma samples were collected from 64 consecutively recruited participants from the University College London FTD cohort studies: 28 participants meeting diagnostic criteria for svPPA1 and 36 healthy controls. There was no statistical difference in age or sex between the two groups (t-test, p=0.934 and Fisher’s exact test, p=1.000, respectively). Participants underwent a standardised clinical and cognitive assessment (table 1) including two measures of semantic knowledge, Wechsler Abbreviated Scale of Intelligence (WASI) Vocabulary subtest and the British Picture Vocabulary Scale (BPVS, a word-picture matching task). They also underwent a 3D T1-weighted MRI of the brain on either a Siemens Trio or Prisma 3T scanner with 55 scans passing initial quality control for cross-sectional analysis (21 participants with svPPA and 34 healthy controls): temporal lobe grey matter volumes (combined left and right hemisphere) were calculated using a previously described automated segmentation technique.3 4 The local ethics committee approved the study and all participants provided written informed consent at enrolment. …

Source: Journal of Neurology Neurosurgery & Psychiatry

DOI: 10.1136/jnnp-2020-325085