Increased phosphorylated tau (pTau-181) is associated with neurological post-acute sequelae of coronavirus disease in essential workers: a prospective cohort study before and after COVID-19 onset

The COVID-19 pandemic led to a spectrum of post-acute sequelae including several neurological complications including cognitive dysfunction labelled Neurological PASC (N-PASC). We hypothesised that N-PASC was associated with changes in neurological biomarkers after COVID-19.

N-PASC was established when individuals reported accepted neurological symptoms persisting for ≥3 months arising alongside validated COVID-19. Plasma samples were retrieved from before and after COVID-19 onset among all (n = 227) essential workers who developed COVID-19 with N-PASC and demographically matched with data from 227 controls who either developed COVID-19 without N-PASC (n = 124) or did not develop COVID-19 before follow-up (n = 103). We used single molecular analysis measured pTau-181, GFAP, NfL, Aβ40/42, and total Aβ burden (IAB). Risk factors for N-PASC were examined prior to COVID-19 infection. Multivariable adjusted generalised linear longitudinal modelling with random intercepts was used to examine changes in biomarkers after COVID-19 onset.