Your browser doesn't support javascript.
COVID-19-related neuropathology and microglial activation in elderly with and without dementia.
Poloni, Tino Emanuele; Medici, Valentina; Moretti, Matteo; Visonà, Silvia Damiana; Cirrincione, Alice; Carlos, Arenn Faye; Davin, Annalisa; Gagliardi, Stella; Pansarasa, Orietta; Cereda, Cristina; Tronconi, Livio; Guaita, Antonio; Ceroni, Mauro.
  • Poloni TE; Department of Neurology and Neuropathology, Abbiategrasso Brain Bank, Golgi-Cenci Foundation, Milan, Italy.
  • Medici V; Department of Rehabilitation, ASP Golgi-Redaelli, Milan, Italy.
  • Moretti M; Department of Neurology and Neuropathology, Abbiategrasso Brain Bank, Golgi-Cenci Foundation, Milan, Italy.
  • Visonà SD; Department of Public Health, Experimental and Forensic Medicine, University of Pavia, Pavia, Italy.
  • Cirrincione A; Department of Public Health, Experimental and Forensic Medicine, University of Pavia, Pavia, Italy.
  • Carlos AF; Department of Neurology and Neuropathology, Abbiategrasso Brain Bank, Golgi-Cenci Foundation, Milan, Italy.
  • Davin A; Department of Neurology and Neuropathology, Abbiategrasso Brain Bank, Golgi-Cenci Foundation, Milan, Italy.
  • Gagliardi S; Department of Neurology and Neuropathology, Abbiategrasso Brain Bank, Golgi-Cenci Foundation, Milan, Italy.
  • Pansarasa O; Genomic and Post-Genomic Center, IRCCS Mondino Foundation, Pavia, Italy.
  • Cereda C; Genomic and Post-Genomic Center, IRCCS Mondino Foundation, Pavia, Italy.
  • Tronconi L; Genomic and Post-Genomic Center, IRCCS Mondino Foundation, Pavia, Italy.
  • Guaita A; Department of Public Health, Experimental and Forensic Medicine, University of Pavia, Pavia, Italy.
  • Ceroni M; Department of Forensic Medicine, IRCCS Mondino Foundation, Pavia, Italy.
Brain Pathol ; 31(5): e12997, 2021 09.
Article in English | MEDLINE | ID: covidwho-1273078
ABSTRACT
The actual role of SARS-CoV-2 in brain damage remains controversial due to lack of matched controls. We aim to highlight to what extent is neuropathology determined by SARS-CoV-2 or by pre-existing conditions. Findings of 9 Coronavirus disease 2019 (COVID-19) cases and 6 matched non-COVID controls (mean age 79 y/o) were compared. Brains were analyzed through immunohistochemistry to detect SARS-CoV-2, lymphocytes, astrocytes, endothelium, and microglia. A semi-quantitative scoring was applied to grade microglial activation. Thal-Braak stages and the presence of small vessel disease were determined in all cases. COVID-19 cases had a relatively short clinical course (0-32 days; mean 10 days), and did not undergo mechanical ventilation. Five patients with neurocognitive disorder had delirium. All COVID-19 cases showed non-SARS-CoV-2-specific changes including hypoxic-agonal alterations, and a variable degree of neurodegeneration and/or pre-existent SVD. The neuroinflammatory picture was dominated by ameboid CD68 positive microglia, while only scant lymphocytic presence and very few traces of SARS-CoV-2 were detected. Microglial activation in the brainstem was significantly greater in COVID-19 cases (p = 0.046). Instead, microglial hyperactivation in the frontal cortex and hippocampus was clearly associated to AD pathology (p = 0.001), regardless of the SARS-CoV-2 infection. In COVID-19 cases complicated by delirium (all with neurocognitive disorders), there was a significant enhancement of microglia in the hippocampus (p = 0.048). Although higher in cases with both Alzheimer's pathology and COVID-19, cortical neuroinflammation is not related to COVID-19 per se but mostly to pre-existing neurodegeneration. COVID-19 brains seem to manifest a boosting of innate immunity with microglial reinforcement, and adaptive immunity suppression with low number of brain lymphocytes probably related to systemic lymphopenia. Thus, no neuropathological evidence of SARS-CoV-2-specific encephalitis is detectable. The microglial hyperactivation in the brainstem, and in the hippocampus of COVID-19 patients with delirium, appears as a specific topographical phenomenon, and probably represents the neuropathological basis of the "COVID-19 encephalopathic syndrome" in the elderly.
Subject(s)
Keywords

Full text: Available Collection: International databases Database: MEDLINE Main subject: Microglia / Dementia / COVID-19 / Nervous System Diseases Type of study: Observational study / Prognostic study / Qualitative research Limits: Aged / Female / Humans / Male Language: English Journal: Brain Pathol Journal subject: Brain / Pathology Year: 2021 Document Type: Article Affiliation country: Bpa.12997

Similar

MEDLINE

...
LILACS

LIS


Full text: Available Collection: International databases Database: MEDLINE Main subject: Microglia / Dementia / COVID-19 / Nervous System Diseases Type of study: Observational study / Prognostic study / Qualitative research Limits: Aged / Female / Humans / Male Language: English Journal: Brain Pathol Journal subject: Brain / Pathology Year: 2021 Document Type: Article Affiliation country: Bpa.12997