Neurologic sequelae of COVID-19 are determined by immunologic imprinting from previous coronaviruses

Abstract:

Coronavirus disease 2019 (COVID-19), which is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), remains a global public health emergency. Although SARS-CoV-2 is primarily a respiratory pathogen, extra-respiratory organs, including the CNS, can also be affected. Neurologic symptoms have been observed not only during acute SARS-CoV-2 infection, but also at distance from respiratory disease, also known as long-COVID or neurological post-acute sequelae of COVID-19 (neuroPASC). The pathogenesis of neuroPASC is not well understood, but hypotheses include SARS-CoV-2-induced immune dysfunctions, hormonal dysregulations and persistence of SARS-CoV-2 reservoirs.

In this prospective cohort study, we used a high throughput systems serology approach to dissect the humoral response to SARS-CoV-2 (and other common coronaviruses: 229E, HKU1, NL63 and OC43) in the serum and CSF from 112 infected individuals who developed (n = 18) or did not develop (n = 94) neuroPASC. Unique SARS-CoV-2 humoral profiles were observed in the CSF of neuroPASC compared with serum responses. All antibody isotypes (IgG, IgM, IgA) and subclasses (IgA1-2, IgG1-4) were detected in serum, whereas CSF was characterized by focused IgG1 (and absence of IgM).

These data argue in favour of compartmentalized brain-specific responses against SARS-CoV-2 through selective transfer of antibodies from the serum to the CSF across the blood-brain barrier, rather than intrathecal synthesis, where more diversity in antibody classes/subclasses would be expected.

Compared to individuals who did not develop post-acute complications following infection, individuals with neuroPASC had similar demographic features (median age 65 versus 66.5 years, respectively, P = 0.55; females 33% versus 44%, P = 0.52) but exhibited attenuated systemic antibody responses against SARS-CoV-2, characterized by decreased capacity to activate antibody-dependent complement deposition (ADCD), NK cell activation (ADNKA) and to bind Fcγ receptors. However, surprisingly, neuroPASC individuals showed significantly expanded antibody responses to other common coronaviruses, including 229E, HKU1, NL63 and OC43.

This biased humoral activation across coronaviruses was particularly enriched in neuroPASC individuals with poor outcome, suggesting an ‘original antigenic sin’ (or immunologic imprinting), where pre-existing immune responses against related viruses shape the response to the current infection, as a key prognostic marker of neuroPASC disease.

Overall, these findings point to a pathogenic role for compromised anti-SARS-CoV-2 responses in the CSF, likely resulting in incomplete virus clearance from the brain and persistent neuroinflammation, in the development of post-acute neurologic complications of SARS-CoV-2 infection.

Source: Spatola M, Nziza N, Jung W, Deng Y, Yuan D, Dinoto A, Bozzetti S, Chiodega V, Ferrari S, Lauffenburger DA, Mariotto S, Alter G. Neurologic sequelae of COVID-19 are determined by immunologic imprinting from previous coronaviruses. Brain. 2023 Oct 3;146(10):4292-4305. doi: 10.1093/brain/awad155. PMID: 37161609. https://academic.oup.com/brain/article/146/10/4292/7158783 (Full text)

Sequential multi-omics analysis identifies clinical phenotypes and predictive biomarkers for long COVID

Abstract:

The post-acute sequelae of COVID-19 (PASC), also known as long COVID, is often associated with debilitating symptoms and adverse multisystem consequences. We obtain plasma samples from 117 individuals during and 6 months following their acute phase of infection to comprehensively profile and assess changes in cytokines, proteome, and metabolome.

Network analysis reveals sustained inflammatory response, platelet degranulation, and cellular activation during convalescence accompanied by dysregulation in arginine biosynthesis, methionine metabolism, taurine metabolism, and tricarboxylic acid (TCA) cycle processes.

Furthermore, we develop a prognostic model composed of 20 molecules involved in regulating T cell exhaustion and energy metabolism that can reliably predict adverse clinical outcomes following discharge from acute infection with 83% accuracy and an area under the curve (AUC) of 0.96.

Our study reveals pertinent biological processes during convalescence that differ from acute infection, and it supports the development of specific therapies and biomarkers for patients suffering from long COVID.

Source: Wang K, Khoramjoo M, Srinivasan K, Gordon PMK, Mandal R, Jackson D, Sligl W, Grant MB, Penninger JM, Borchers CH, Wishart DS, Prasad V, Oudit GY. Sequential multi-omics analysis identifies clinical phenotypes and predictive biomarkers for long COVID. Cell Rep Med. 2023 Oct 18:101254. doi: 10.1016/j.xcrm.2023.101254. Epub ahead of print. PMID: 37890487. https://www.cell.com/cell-reports-medicine/fulltext/S2666-3791(23)00431-7 (Full text)

“It was almost like it’s set up for people to fail” A qualitative analysis of experiences and unmet supportive needs of people with Long COVID

Abstract:

Background: Almost twenty percent of adults with COVID-19 develop Long COVID, leading to prolonged symptoms and disability. Understanding the supportive needs of people with Long COVID is vital to enacting effective models of care and policies.

Design/methods: This qualitative sub-study explored the experiences of people with Long COVID and their unmet needs. Participants enrolled in a larger study to evaluate the post-acute cardiovascular impacts of COVID-19 were invited to participate in subsequent in-depth interviews. Participants were enrolled purposively until saturation at 24 participants. Data were analyzed using thematic content analysis.

Results: Participants focused on adaptations to life with Long COVID and their unmet needs in different life spheres. Three domains, 1) occupational and financial; 2) healthcare-related; and 3) social and emotional support, emerged as areas affecting quality of life. Although participants were motivated to return to work for financial and personal reasons, Long COVID symptoms often resulted in the inability to perform tasks required by their existing jobs, and unemployment. Those who maintained employment through employer accommodations still needed additional support. Participants encountered diagnostic challenges, challenges in accessing specialty appointments, insurance loopholes, high healthcare costs, and medical skepticism. Existing social networks provided support for completing daily tasks; however, those with Long COVID typically turned to others with similar lived experiences for emotional support. Participants found government support programs inadequate and difficult to access in all three domains.

Discussion: We propose a five-pronged policy approach to support persons with Long COVID. These overarching recommendations are (1) improve public awareness of Long COVID; (2) improve clinical care quality and access; (3) implement additional school and workplace accommodations; (4) strengthen socioeconomic benefits and social services; and (5) improve research on Long COVID.

Source: McNabb, K.C., Bergman, A.J., Smith-Wright, R. et al. “It was almost like it’s set up for people to fail” A qualitative analysis of experiences and unmet supportive needs of people with Long COVID. BMC Public Health 23, 2131 (2023). https://doi.org/10.1186/s12889-023-17033-4 https://bmcpublichealth.biomedcentral.com/articles/10.1186/s12889-023-17033-4 (Full text)

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (Me/Cfs): The Biology of a Neglected Disease

Abstract:

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a chronic disease with debilitating symptoms that impact all aspects of life. The diverse symptom presentation indicates that ME/CFS is likely to have a multifactorial origin. However, it is an extremely understudied disease with no standardised diagnostic criteria or proven treatment avenues. It is hypothesised that environmental insults (such as acute infection, mainly viral) or stress in genetically susceptible individuals may trigger the development of ME/CFS.

These insults result in acute inflammatory responses, along with aberrant immune activation. A spiralling disruption of homeostasis promotes subsequent patho-mechanisms including gut dysbiosis and systemic inflammation, and eventually a pathological clotting system, chronic endothelialitis, vasoconstriction, and hypoxia. Additionally, dysfunctional energy metabolism including oxidative stress is also present in the development of ME/CFS. Since the exact pathophysiology of ME/CFS remains unclear, additional research is required to reveal further insight into this “neglected” disease.

Source: Arron, Hayley and Marsh, Benamin and Khan, M. Asad and Jaeger, Beate and Kell, Douglas and Pretorius, Etheresia, Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (Me/Cfs): The Biology of a Neglected Disease. Available at SSRN: https://ssrn.com/abstract=4622074 or http://dx.doi.org/10.2139/ssrn.4622074 (Full text available as PDF file)

Prevalence and Predictive Factors of Small Intestinal Bacterial Overgrowth in Patients With Chronic Fatigue Syndrome

Introduction: Chronic fatigue syndrome (CFS) is a poorly understood illness, characterized by fatigue and related symptoms including cognitive dysfunction, headaches, joint pains, and gastrointestinal distress. Irritable bowel syndrome (IBS) is common and present in approximately 60% patients with CFS while the prevalence of small intestinal bacterial overgrowth (SIBO) in IBS is approximately 40%. Our study aimed to 1) Determine the prevalence of SIBO in patients with CFS with and without IBS symptoms 2) Identify factors associated with increased risk of SIBO.

Methods: A retrospective chart review of 479 patients with CFS referred for hydrogen/methane breath testing. Clinical documentation was reviewed to identify positive breath test result diagnosing SIBO. Statistical analysis was conducted with 2-proportions z test and logistic regression analysis to identify predictive variables of SIBO diagnosis.

Results: 479 patients with CFS referred for glucose or lactulose breath testing were identified. Three hundred sixty-seven of those patients completed a breath test with available result: 152(41%) SIBO+ (mean age (SD) 50 (17)), 164(45%) SIBO- (mean age SD 46 (15)), and 78(21%) equivocal results. In CFS patients with conclusive breath test result, 48% tested positive for SIBO, and the diagnosis of IBS was present in 186/316 (59%). There was no difference in the prevalence of IBS between the SIBO+ vs SIBO-group [98/152 (64%) vs 88/164 (53%), P < 0.05]. Using multiple logistic regression analysis, age, unknown race, and IBS diagnosis all significantly predicted increased odds of having a positive breath test (Table 1). Conversely, PPI use was associated with decreased odds of a positive breath test. Due to the high prevalence of IBS in our cohort and the association between IBS and SIBO, an analysis was performed excluding patients with IBS diagnosis. When excluding patients with IBS, unknown race and TCA use were associated with increased odds of positive breath test, while diarrhea, hypothyroidism, PPI, and naltrexone use were associated with decreased odds (P< 0.05).

Conclusion: SIBO is highly prevalent in patients with CFS referred for breath testing. Older age and comorbid IBS diagnosis predict increased odds of positive breath test. Surprisingly, PPI use predicted decreased odds despite its prior implication as a possible risk factor for SIBO. Further studies are needed to explore the underlying mechanism causing the overlap between CFS, IBS and SIBO which may provide insights into potential therapies for CFS.

Source: Karhu, Elisa MD, MS; Neshatian, Leila MD, MS; Fass, Ofer MD; Sonu, Irene MD; Nguyen, Linda Anh MD. S1821 Prevalence and Predictive Factors of Small Intestinal Bacterial Overgrowth in Patients With Chronic Fatigue Syndrome. The American Journal of Gastroenterology 118(10S):p S1351-S1352, October 2023. | DOI: 10.14309/01.ajg.0000956924.26236.c4 https://journals.lww.com/ajg/fulltext/2023/10001/s1821_prevalence_and_predictive_factors_of_small.2162.aspx

The economic burden of myalgic encephalomyelitis/chronic fatigue syndrome in Australia

Abstract:

Objective Estimate costs of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) to patients, government, and Australian society.

Methods Australian ME/CFS patients and their carers were recruited using convenience sampling. Patients completed an online retrospective cost diary, providing ME/CFS-related direct medical, non-medical and indirect costs. Informal care costs were collected directly from carers. Data from the Pharmaceutical Benefits Scheme and Medicare Benefits Schedule were linked to participant survey data. Annual per/patient and total societal costs were estimated, and broken down by category, and presented in 2021AUD. Factors associated with higher costs were investigated using generalized linear models.

Results 175 patients (mean/SD age of 49/14 years, 79.4% female) completed the cost diary. Estimated total annual societal costs of ME/CFS in Australia ranged between $1.38 and $10.09billion, with average annual total costs of $63,400/patient. Three-quarters of these costs were due to indirect costs ($46,731). Disability severity was the key factor associated with higher costs, particularly for indirect costs (being 2.27-fold higher for severe disability than no/mild disability).

Conclusions ME/CFS poses a significant economic burden in Australia, owing mainly to high indirect and informal care costs.

Source: Ting Zhao, Ingrid Cox, Hasnat Ahmed, Julie Campbell, Martin Hensher, Andrew Palmer, Ryan Kelly, Melissa Rogerson, Karen Wills, Barbara de Graaff. The economic burden of myalgic encephalomyelitis/chronic fatigue syndrome in Australia. Australian Health Review. AH23106 Accepted 07 November 2023 https://www.publish.csiro.au/AH/justaccepted/AH23106

Physical exertion worsens symptoms in patients with post-COVID condition : Post-exertional malaise in patients with post-COVID condition

Abstract:

Patients with post-COVID condition suffer from fatigue, limited exercise capacity, and post-exertional malaise. Post-exertional malaise is the worsening of symptoms after physical or mental exertion, which reduces the efficacy of most forms of rehabilitation. This article presents the current understanding in the pathophysiology of post-COVID condition, particularly the underlying causes of post-exertional malaise.

Source: Ellen Breedveld, Braeden Charlton and Brent Appelman et al. Physical exertion worsens symptoms in patients with post-COVID condition. ScienceOpen Preprints. 2023. DOI: 10.14293/PR2199.000467.v1 https://www.scienceopen.com/document/read?vid=6ebbad1a-4c23-4323-b20c-e57a346ce9f9 (Full text)

Patient perspectives of recovery from myalgic encephalomyelitis/chronic fatigue syndrome: An interpretive description study

Abstract:

Aims and objectives: Myalgic encephalomyelitis (ME), also called chronic fatigue syndrome (CFS), is characterised by persistent fatigue, postexertional malaise, and cognitive dysfunction. It is a complex, long-term, and debilitating illness without widely effective treatments. This study describes the treatment choices and experiences of ME/CFS patients who have experienced variable levels of recovery.

Method: Interpretive description study consisting of semi-structured qualitative interviews with 33 people who met the US Centers for Disease Control (2015) diagnostic criteria for ME/CFS and report recovery or symptom improvement.

Results: Twenty-six participants endorsed partial recovery, and seven reported full recovery from ME/CFS. Participants reported expending significant time and energy to identify, implement, and adapt therapeutic interventions, often without the guidance of a medical practitioner. They formulated individualised treatment plans reflecting their understanding of their illness and personal resources. Most fully recovered participants attributed their success to mind-body approaches.

Conclusion: Patients with ME/CFS describe independently constructing and managing treatment plans, due to a lack of health system support. Stigmatised and dismissive responses from clinicians precipitated disengagement from the medical system and prompted use of other forms of treatment.

Source: Hasan Z, Kuyvenhoven C, Chowdhury M, Amoudi L, Zeraatkar D, Busse JW, Sadik M, Vanstone M. Patient perspectives of recovery from myalgic encephalomyelitis/chronic fatigue syndrome: An interpretive description study. J Eval Clin Pract. 2023 Nov 6. doi: 10.1111/jep.13938. Epub ahead of print. PMID: 37927138. https://onlinelibrary.wiley.com/doi/10.1111/jep.13938 (Full text)

Long-term neurological implications of severe acute respiratory syndrome coronavirus 2 infections in neonates: Innate immune memory and chronic neuroinflammation

Abstract:

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can cause long-term neurological complications in adults. However, the mechanisms by which early-life SARS-CoV-2 infection increases the risk of abnormal neurodevelopment remain unknown.

Recent studies have shown an association with chronic proinflammatory cytokine/chemokine production in the central nervous system (CNS). Therefore, it was hypothesised that innate immune activation and induction of innate immune memory may play a potential role in the neonatal brain. Haematopoietic stem cells in the bone marrow are exposed to SARS-CoV-2, SARS-CoV-2 envelope protein (E protein), lipopolysaccharide (LPS)-bound spike proteins (S1 and S2 proteins), and damage-associated molecular patterns (DAMPs). Myeloid progenitors enter the stroma of the choroid plexus and are further directed to incessantly supply the brain parenchyma with resident innate immune cells. The S proteins-LPS complex can cross the blood–brain barrier and plays an important role in microglial and astrocytic inflammatory responses and innate immune memory.

Persistently activated microglia with memory release pro-inflammatory cytokines/chemokines which contribute to abnormal synaptic development in the frontal lobe and cerebellum, potentially leading to long-term neurological complications, similar to those observed in autism spectrum disorder (ASD). In addition, this hypothesis suggests that bacterial and fungal products may act as adjuvants to S proteins and may also explain why S proteins alone are insufficient to induce neuroinflammation in neonates.

Source: Tatsuro Nobutoki. Long-term neurological implications of severe acute respiratory syndrome coronavirus 2 infections in neonates: Innate immune memory and chronic neuroinflammation. Medical Hypotheses, Volume 181, December 2023, 111204 https://www.sciencedirect.com/science/article/pii/S0306987723002001 (Full text)

SARS-CoV-2 viral persistence in lung alveolar macrophages is controlled by IFN-γ and NK cells

Abstract:

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA generally becomes undetectable in upper airways after a few days or weeks postinfection. Here we used a model of viral infection in macaques to address whether SARS-CoV-2 persists in the body and which mechanisms regulate its persistence.

Replication-competent virus was detected in bronchioalveolar lavage (BAL) macrophages beyond 6 months postinfection. Viral propagation in BAL macrophages occurred from cell to cell and was inhibited by interferon-γ (IFN-γ). IFN-γ production was strongest in BAL NKG2r+CD8+ T cells and NKG2Alo natural killer (NK) cells and was further increased in NKG2Alo NK cells after spike protein stimulation.

However, IFN-γ production was impaired in NK cells from macaques with persisting virus. Moreover, IFN-γ also enhanced the expression of major histocompatibility complex (MHC)-E on BAL macrophages, possibly inhibiting NK cell-mediated killing. Macaques with less persisting virus mounted adaptive NK cells that escaped the MHC-E-dependent inhibition.

Our findings reveal an interplay between NK cells and macrophages that regulated SARS-CoV-2 persistence in macrophages and was mediated by IFN-γ.

Source: Huot N, Planchais C, Rosenbaum P, Contreras V, Jacquelin B, Petitdemange C, Lazzerini M, Beaumont E, Orta-Resendiz A, Rey FA, Reeves RK, Le Grand R, Mouquet H, Müller-Trutwin M. SARS-CoV-2 viral persistence in lung alveolar macrophages is controlled by IFN-γ and NK cells. Nat Immunol. 2023 Nov 2. doi: 10.1038/s41590-023-01661-4. Epub ahead of print. PMID: 37919524. https://www.nature.com/articles/s41590-023-01661-4 (Full text)