Tag: brain inflammation

Cortical thickness alterations and systemic inflammation define long-COVID patients with cognitive impairment

Abstract:

As the heterogeneity of symptoms is increasingly recognized among long-COVID patients, it appears highly relevant to study potential pathophysiological differences along the different subtypes. Preliminary evidence suggests distinct alterations in brain structure and systemic inflammatory patterns in specific groups of long-COVID patients.

To this end, we analyzed differences in cortical thickness and peripheral immune signature between clinical subgroups based on 3T-MRI scans and signature inflammatory markers in n=120 participants comprising healthy never-infected controls, healthy COVID-19 survivors, and subgroups of long-COVID patients with and without cognitive impairment according to screening with Montreal Cognitive Assessment.

Whole-brain comparison of cortical thickness between the 4 groups was conducted by surface-based morphometry. We identified distinct cortical areas showing a progressive increase in cortical thickness across different groups, starting from healthy individuals who had never been infected with COVID-19, followed by healthy COVID-19 survivors, long-COVID patients without cognitive deficits (MoCA ≥ 26), and finally, long-COVID patients exhibiting significant cognitive deficits (MoCA < 26). These findings highlight the continuum of cortical thickness alterations associated with COVID-19, with more pronounced changes observed in individuals experiencing cognitive impairment (p<0.05, FWE-corrected).

Affected cortical regions covered prefrontal and temporal gyri, insula, posterior cingulate, parahippocampal gyrus, and parietal areas. Additionally, we discovered a distinct immunophenotype, with elevated levels of IL-10, IFNg, and sTREM2 in long-COVID patients, especially in the group suffering from cognitive impairment.

We demonstrate lingering cortical and immunological alterations in healthy and impaired subgroups of COVID-19 survivors. This implies a complex underlying pathomechanism in long-COVID and emphasizes the necessity to investigate the whole spectrum of post-COVID biology to determine targeted treatment strategies targeting specific sub-groups.

Source: Bianca Besteher, Tonia Rocktaeschel, Alejandra Patricia Garza, Marlene Machnik, Johanna Ballez, Dario Lucas Helbing, Katrhin Finke, Philipp Reuken, Daniel Guellmar, Christian Gaser, Martin Walter, Nils Opel, Ildiko Rita Dunay. Cortical thickness alterations and systemic inflammation define long-COVID patients with cognitive impairment. medRxiv 2023.07.21.23292988; doi: https://doi.org/10.1101/2023.07.21.23292988 https://www.medrxiv.org/content/10.1101/2023.07.21.23292988v1v (Full text available as PDF file)

Neuroinflammation After COVID-19 With Persistent Depressive and Cognitive Symptoms

Abstract:

Importance: Persistent depressive symptoms, often accompanied by cognitive symptoms, commonly occur after COVID-19 illness (hereinafter termed COVID-DC, DC for depressive and/or cognitive symptoms). In patients with COVID-DC, gliosis, an inflammatory change, was suspected, but measurements of gliosis had not been studied in the brain for this condition.

Objective: To determine whether translocator protein total distribution volume (TSPO VT), a marker of gliosis that is quantifiable with positron emission tomography (PET), is elevated in the dorsal putamen, ventral striatum, prefrontal cortex, anterior cingulate cortex, and hippocampus of persons with COVID-DC.

Design, setting, and participants: This case-control study conducted at a tertiary care psychiatric hospital in Canada from April 1, 2021, to June 30, 2022, compared TSPO VT of specific brain regions in 20 participants with COVID-DC with that in 20 healthy controls. The TSPO VT was measured with fluorine F 18-labeled N-(2-(2-fluoroethoxy)benzyl)-N-(4-phenoxypyridin-3-yl)acetamide ([18F]FEPPA) PET.

Main outcomes and measures: The TSPO VT was measured in the dorsal putamen, ventral striatum, prefrontal cortex, anterior cingulate cortex, and hippocampus. Symptoms were measured with neuropsychological and psychological tests, prioritizing outcomes related to striatal function.

Results: The study population included 40 participants (mean [SD] age, 32.9 [12.3] years). The TSPO VT across the regions of interest was greater in persons with COVID-DC (mean [SD] age, 32.7 [11.4] years; 12 [60%] women) compared with healthy control participants (mean [SD] age, 33.3 [13.9] years; 11 [55%] women): mean (SD) difference, 1.51 (4.47); 95% CI, 0.04-2.98; 1.51 divided by 9.20 (17%). The difference was most prominent in the ventral striatum (mean [SD] difference, 1.97 [4.88]; 95% CI, 0.36-3.58; 1.97 divided by 8.87 [22%]) and dorsal putamen (mean difference, 1.70 [4.25]; 95% CI, 0.34-3.06; 1.70 divided by 8.37 [20%]). Motor speed on the finger-tapping test negatively correlated with dorsal putamen TSPO VT (r, -0.53; 95% CI, -0.79 to -0.09), and the 10 persons with the slowest speed among those with COVID-DC had higher dorsal putamen TSPO VT than healthy persons by 2.3 (2.30 divided by 8.37 [27%]; SD, 2.46; 95% CI, 0.92-3.68).

Conclusions and relevance: In this case-control study, TSPO VT was higher in patients with COVID-DC. Greater TSPO VT is evidence for an inflammatory change of elevated gliosis in the brain of an individual with COVID-DC. Gliosis may be consequent to inflammation, injury, or both, particularly in the ventral striatum and dorsal putamen, which may explain some persistent depressive and cognitive symptoms, including slowed motor speed, low motivation or energy, and anhedonia, after initially mild to moderate COVID-19 illness.

Source: Braga J, Lepra M, Kish SJ, Rusjan PM, Nasser Z, Verhoeff N, Vasdev N, Bagby M, Boileau I, Husain MI, Kolla N, Garcia A, Chao T, Mizrahi R, Faiz K, Vieira EL, Meyer JH. Neuroinflammation After COVID-19 With Persistent Depressive and Cognitive Symptoms. JAMA Psychiatry. 2023 May 31:e231321. doi: 10.1001/jamapsychiatry.2023.1321. Epub ahead of print. PMID: 37256580; PMCID: PMC10233457. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10233457/ (Full text)

Brain autopsies of critically ill COVID-19 patients demonstrate heterogeneous profile of acute vascular injury, inflammation and age-linked chronic brain diseases

Abstract:

Background: This study examined neuropathological findings of patients who died following hospitalization in an intensive care unit with SARS-CoV-2.

Methods: Data originate from 20 decedents who underwent brain autopsy followed by ex-vivo imaging and dissection. Systematic neuropathologic examinations were performed to assess histopathologic changes including cerebrovascular disease and tissue injury, neurodegenerative diseases, and inflammatory response. Cerebrospinal fluid (CSF) and fixed tissues were evaluated for the presence of viral RNA and protein.

Results: The mean age-at-death was 66.2 years (range: 26-97 years) and 14 were male. The patient’s medical history included cardiovascular risk factors or diseases (n = 11, 55%) and dementia (n = 5, 25%). Brain examination revealed a range of acute and chronic pathologies. Acute vascular pathologic changes were common in 16 (80%) subjects and included infarctions (n = 11, 55%) followed by acute hypoxic/ischemic injury (n = 9, 45%) and hemorrhages (n = 7, 35%). These acute pathologic changes were identified in both younger and older groups and those with and without vascular risk factors or diseases. Moderate-to-severe microglial activation were noted in 16 (80%) brains, while moderate-to-severe T lymphocyte accumulation was present in 5 (25%) brains. Encephalitis-like changes included lymphocytic cuffing (n = 6, 30%) and neuronophagia or microglial nodule (most prominent in the brainstem, n = 6, 30%) were also observed. A single brain showed vasculitis-like changes and one other exhibited foci of necrosis with ball-ring hemorrhages reminiscent of acute hemorrhagic leukoencephalopathy changes. Chronic pathologies were identified in only older decedents: 7 brains exhibited neurodegenerative diseases and 8 brains showed vascular disease pathologies. CSF and brain samples did not show evidence of viral RNA or protein.

Conclusions: Acute tissue injuries and microglial activation were the most common abnormalities in COVID-19 brains. Focal evidence of encephalitis-like changes was noted despite the lack of detectable virus. The majority of older subjects showed age-related brain pathologies even in the absence of known neurologic disease. Findings of this study suggest that acute brain injury superimposed on common pre-existing brain disease may put older subjects at higher risk of post-COVID neurologic sequelae.

Source: Agrawal S, Farfel JM, Arfanakis K, Al-Harthi L, Shull T, Teppen TL, Evia AM, Patel MB, Ely EW, Leurgans SE, Bennett DA, Mehta R, Schneider JA. Brain autopsies of critically ill COVID-19 patients demonstrate heterogeneous profile of acute vascular injury, inflammation and age-linked chronic brain diseases. Acta Neuropathol Commun. 2022 Dec 17;10(1):186. doi: 10.1186/s40478-022-01493-7. PMID: 36528671; PMCID: PMC9758667. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9758667/ (Full text)

Molecular and cellular similarities in the brain of SARS-CoV-2 and Alzheimer’s disease individuals

Abstract:

Infection with the etiological agent of COVID-19, SARS-CoV-2, appears capable of impacting cognition, which some patients with Post-acute Sequelae of SARS-CoV-2 (PASC). To evaluate neuro-pathophysiological consequences of SARS-CoV-2 infection, we examine transcriptional and cellular signatures in the Broadman area 9 (BA9) of the frontal cortex and the hippocampal formation (HF) in SARS-CoV-2, Alzheimer’s disease (AD) and SARS-CoV-2 infected AD individuals, compared to age- and gender-matched neurological cases. Here we show similar alterations of neuroinflammation and blood-brain barrier integrity in SARS-CoV-2, AD, and SARS-CoV-2 infected AD individuals. ‘

Distribution of microglial changes reflected by the increase of Iba-1 reveal nodular morphological alterations in SARS-CoV-2 infected AD individuals. Similarly, HIF-1α is significantly upregulated in the context of SARS-CoV-2 infection in the same brain regions regardless of AD status. The finding may help to inform decision-making regarding therapeutic treatments in patients with neuro-PASC, especially those at increased risk of developing AD.

Source: Griggs E, Trageser K, Naughton S, Yang EJ, Mathew B, Van Hyfte G, Hellmers L, Jette N, Estill M, Shen L, Fischer T, Pasinetti GM. Molecular and cellular similarities in the brain of SARS-CoV-2 and Alzheimer’s disease individuals. bioRxiv [Preprint]. 2022 Nov 23:2022.11.23.517706. doi: 10.1101/2022.11.23.517706. PMID: 36451886; PMCID: PMC9709800. https://www.biorxiv.org/content/10.1101/2022.11.23.517706v1.full (Full text)

Long COVID is associated with extensive in-vivo neuroinflammation on [18F]DPA-714 PET

Abstract:

A significant number of COVID-19 patients develop ‘long COVID’, a condition defined by long-lasting debilitating, often neurological, symptoms. The pathophysiology of long COVID is unknown. Here we present in-vivo evidence of widespread neuroinflammation in long COVID, using a quantitative assessment, [18F]DPA-714 PET, in two long COVID patients. We reanalyzed historical data from three matched healthy control subjects, for comparison purposes. Both patients with long COVID had widespread increases in [18F]DPA-714 binding throughout the brain. Quantitative measures of binding (BPND values) were increased on average by 121% and 76%, respectively. This implicates profound neuroinflammation in the pathophysiology of long COVID.

Source: Denise Visser, Sandeep S.V. Golla, Sander C.J. Verfaillie, Emma M. Coomans, Roos M. Rikken, Elsmarieke M. van de Giessen, Marijke E. den Hollander, Anouk Verveen, Maqsood Yaqub, Frederik Barkhof, Janneke Horn, Bart Koopman, Patrick Schober, Dook W. Koch, Robert C. Schuit, Albert D. Windhorst, Michael Kassiou, Ronald Boellaard, Michele van Vugt, Hans Knoop, Nelleke Tolboom, Bart N.M. van Berckel. Long COVID is associated with extensive in-vivo neuroinflammation on [18F]DPA-714 PET. medRxiv 2022.06.02.22275916; doi: https://doi.org/10.1101/2022.06.02.22275916 https://www.medrxiv.org/content/10.1101/2022.06.02.22275916v1.full-text (Full text)

Off label use of Aripiprazole shows promise as a treatment for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): a retrospective study of 101 patients treated with a low dose of Aripiprazole

Note: The ME Association does not recommend that anyone with ME/CFS attempt to obtain or to take this drug, even in small doses, until such time as more appropriate research can better determine safety and efficacy. Read their full statement here. 

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a chronic, debilitating illness of unknown etiology. An ME/CFS diagnosis is based solely on symptoms with case definitions made by expert consensus, including the Fukuda (1994), Canadian Consensus Criteria (CCC, 2003), International Consensus Criteria (ICC, 2011), and the Institute of Medicine (IOM, 2015) case criteria. According to the most recent IOM case definition, the core symptoms of ME/CFS include debilitating fatigue, unrefreshing sleep, post-exertional malaise, and either cognitive dysfunction or orthostatic intolerance [1]. Although the cause of the illness is unknown, a growing body of evidence suggests that ME/CFS involves inflammation of the brain. Up to 85% of patients with ME/CFS report symptoms of cognitive impairment also referred to as “brain fog,” which includes difficulty with memory, attention, and information processing. Additional evidence includes changes in inflammatory cytokines in both plasma and cerebrospinal fluid correlated with the severity of symptoms [2]. Other studies using positron emission tomography (PET) show evidence of activated microglia or astrocytes in various regions of the brain in patients with ME/CFS [3].

Source: Crosby, L.D., Kalanidhi, S., Bonilla, A. et al. Off label use of Aripiprazole shows promise as a treatment for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): a retrospective study of 101 patients treated with a low dose of Aripiprazole. J Transl Med 19, 50 (2021). https://doi.org/10.1186/s12967-021-02721-9 https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-021-02721-9 (Full text)