Elevation of Neurodegenerative Serum Biomarkers among Hospitalized COVID-19 Patients

INTRODUCTION: Older adults hospitalized with COVID-19 are susceptible to neurological complications, particularly encephalopathy, which may reflect age-related neurodegenerative processes. METHODS: Serum total tau, ptau-181, GFAP, NFL, UCHL1, and amyloid-beta(AB-40,42) were measured in hospitalized COVID-19 patients without a history of dementia, and compared among patients with or without encephalopathy, in-hospital death versus survival, and discharge home versus other dispositions using multivariable Cox proportional hazards regression analyses. RESULTS: Among 251 patients, admission serum ptau-181 and UCHL1 were significantly elevated in patients with encephalopathy (both P<0.05) and total tau, GFAP, and NFL were significantly lower in those discharged home(all P<0.05). These markers correlated significantly with severity of COVID illness. NFL, GFAP and UCH-L1 were significantly higher in hospitalized COVID patients than in non-COVID controls with mild cognitive impairment or Alzheimer9s disease(AD). DISCUSSION: Age-related neurodegenerative biomarkers were elevated to levels observed in AD and associated with encephalopathy and worse outcomes among hospitalized COVID-19 patients.