Prolonged T-cell activation and long COVID symptoms independently associate with severe COVID-19 at 3 months

Abstract:

COVID-19 causes immune perturbations which may persist long-term, and patients frequently report ongoing symptoms for months after recovery. We assessed immune activation at 3-12 months post hospital admission in 187 samples from 63 patients with mild, moderate or severe disease and investigated whether it associates with long COVID.

At 3 months, patients with severe disease displayed persistent activation of CD4+ and CD8+ T-cells, based on expression of HLA-DR, CD38, Ki67 and granzyme B, and elevated plasma levels of IL-4, IL-7, IL-17 and TNF-α compared to mild and/or moderate patients. Plasma from severe patients at 3 months caused T-cells from healthy donors to upregulate IL-15Rα, suggesting that plasma factors in severe patients may increase T-cell responsiveness to IL-15-driven bystander activation.

Patients with severe disease reported a higher number of long COVID symptoms which did not however, correlate with cellular immune activation/pro-inflammatory cytokines after adjusting for age, sex and disease severity. Our data suggests that long COVID and persistent immune activation may correlate independently with severe disease.

Source: Marianna Santopaolo, Michaela Gregorova, Fergus Hamilton, David Arnold, Anna Long, Aurora Lacey, Alice Halliday, Holly Baum, Kristy Hamilton, Rachel Milligan, Elizabeth Oliver, Olivia Pearce, Lea Knezevic, Begonia Morales Aza, Alice Milne, Emily Milodowski, Eben Jones, Rajeka Lazarus, Anu Goenka, Adam Finn, Nicholas Maskell, Andrew D Davidson, Kathleen Gillespie, Linda Wooldridge, Laura Rivino (2023) Prolonged T-cell activation and long COVID symptoms independently associate with severe COVID-19 at 3 months eLife 12:e85009 https://doi.org/10.7554/eLife.85009 https://elifesciences.org/articles/85009

Persistent serum protein signatures define an inflammatory subcategory of long COVID

Abstract:

Long COVID or post-acute sequelae of SARS-CoV-2 (PASC) is a clinical syndrome featuring diverse symptoms that can persist for months following acute SARS-CoV-2 infection. The aetiologies may include persistent inflammation, unresolved tissue damage or delayed clearance of viral protein or RNA, but the biological differences they represent are not fully understood. Here we evaluate the serum proteome in samples, longitudinally collected from 55 PASC individuals with symptoms lasting ≥60 days after onset of acute infection, in comparison to samples from symptomatically recovered SARS-CoV-2 infected and uninfected individuals.

Our analysis indicates heterogeneity in PASC and identified subsets with distinct signatures of persistent inflammation. Type II interferon signaling and canonical NF-κB signaling (particularly associated with TNF), appear to be the most differentially enriched signaling pathways, distinguishing a group of patients characterized also by a persistent neutrophil activation signature.

These findings help to clarify biological diversity within PASC, identify participants with molecular evidence of persistent inflammation, and highlight dominant pathways that may have diagnostic or therapeutic relevance, including a protein panel that we propose as having diagnostic utility for differentiating inflammatory and non-inflammatory PASC.

Source: Talla, A., Vasaikar, S.V., Szeto, G.L. et al. Persistent serum protein signatures define an inflammatory subcategory of long COVID. Nat Commun 14, 3417 (2023). https://doi.org/10.1038/s41467-023-38682-4 https://www.nature.com/articles/s41467-023-38682-4 (Full text)

Changes in the proteomics of exhaled breath condensate under the influence of inhaled hydrogen in patients with post-COVID syndrome.

Abstract:

Purpose. To study the effect of inhalation therapy with an active form of hydrogen (APH) on the protein composition of exhaled air condensate (EAC) in patients with post-COVID syndrome (PCS).

Material and methods. A randomized controlled parallel prospective study included 60 patients who had a novel coronavirus infection (COVID-19, COronaVIrus Disease 2019) with PCD during the recovery period, had clinical manifestations of chronic fatigue syndrome and received standard therapy according to the protocol for managing patients with chronic fatigue syndrome. The patients were divided into 2 groups: group 1 (main) – 30 people who received standard therapy and APV inhalations (device “SUISONIA”, Japan) for 10 days, and group 2 (control) – 30 medical workers who received only standard therapy. Patients in both groups were comparable in terms of gender and mean age. All participants in the study on the 1st and 10th days. samples were taken from the CVV.

Results. A total of 478 proteins and 1350 peptides were identified using high resolution mass spectrometry. The number of proteins in samples after APV therapy, on average, is 12% more than before treatment. An analysis of the distribution of proteins in different groups of patients showed that only half of these proteins (112) are common for all groups of samples and are detected in EVC before, after, and regardless of hydrogen therapy. In addition to the qualitative difference in the protein compositions of CEA in different groups, quantitative changes in the concentration of 36 proteins (mainly structural and protective) were also detected, which together made it possible to reliably distinguish between subgroups before and after treatment. It is important to note that among these proteins there are participants in the processes of blood coagulation (a-1-antitrypsin), mediated by chemokines and cytokines of inflammation,

Conclusion. The use of hydrogen therapy can contribute to the switching of a number of physiological processes, which may affect the success of restorative treatment in PKD. In particular, the obtained results indicate the activation of aerobic synthesis of adenosine triphosphate in mitochondria by hydrogen therapy, which correlates well with the decrease in blood lactate levels detected by laboratory studies in the studied patients. At the same time, it is important that this therapy can inhibit pro-inflammatory activity, negatively affecting the coagulation processes and signaling pathways of integrins and apoptosis, and, in addition, activate protective pathways, the tricarboxylic acid cycle, FAS signaling, and purine metabolism, which can be significant. for effective recovery after suffering COVID-19.

Source: Ryabokon, A. M.; Zakharova, N. V.; Indeikina, M. I.; Kononikhin, A. S.; Shogenova, L. V.; Medvedev, O. S.; Kostinov, M. P.; Svitich, O. A.; Ibaraki, K.; Maehara, H.; Nikolaev, E. N.; Varfolomeev, S. D.; Chuchalin, A. G. Changes in the proteomics of exhaled breath condensate under the influence of inhaled hydrogen in patients with post-COVID syndrome. Cardiovascular Therapy and Prevention (Russian Federation) ; 22(3):50-59, 2023. https://www.researchgate.net/publication/369954717_Changes_in_the_proteomics_of_exhaled_breath_condensate_under_the_influence_of_inhaled_hydrogen_in_patients_with_post-COVID_syndrome

Imbalance of Peripheral Temperature, Sympathovagal, and Cytokine Profile in Long COVID

Simple Summary:

In this study, we looked at how persistent inflammation affects peripheral body temperature and sympathovagal balance in individuals with long COVID. Increased temperature and reduced heart rate variability were directly related to the increase in inflammatory cytokines and reduction in anti-inflammatory cytokines. We identified a possible “molecular signature” for long COVID, characterised by a Th17 inflammatory profile with a reduced anti-inflammatory response, resulting in alterations in homeostatic functions and sympathovagal balance.

Abstract:

A persistent state of inflammation has been reported during the COVID-19 pandemic. This study aimed to assess short-term heart rate variability (HRV), peripheral body temperature, and serum cytokine levels in patients with long COVID. We evaluated 202 patients with long COVID symptoms categorized them according to the duration of their COVID symptoms (≤120 days, n = 81; >120 days, n = 121), in addition to 95 healthy individuals selected as controls.
All HRV variables differed significantly between the control group and patients with long COVID in the ≤120 days group (p < 0.05), and participants in the long COVID ≤120 days group had higher temperatures than those in the long COVID >120 days group in all regions analysed (p < 0.05).
Cytokine analysis showed higher levels of interleukin 17 (IL-17) and interleukin 2 (IL-2), and lower levels of interleukin 4 (IL-4) (p < 0.05). Our results suggest a reduction in parasympathetic activation during long COVID and an increase in body temperature due to possible endothelial damage caused by the maintenance of elevated levels of inflammatory mediators.
Furthermore, high serum levels of IL-17 and IL-2 and low levels of IL-4 appear to constitute a long-term profile of COVID-19 cytokines, and these markers are potential targets for long COVID-treatment and prevention strategies.
Source: Neves PFMd, Quaresma JAS, Queiroz MAF, Silva CC, Maia EV, Oliveira JSdS, Neves CMAd, Mendonça SdS, Falcão ASC, Melo GS, Santos IBF, Sousa JRd, Santos EJMd, Vasconcelos PFdC, Vallinoto ACR, Falcão LFM. Imbalance of Peripheral Temperature, Sympathovagal, and Cytokine Profile in Long COVID. Biology. 2023; 12(5):749. https://doi.org/10.3390/biology12050749 https://www.mdpi.com/2079-7737/12/5/749 (Full text)

Review of Neurological Manifestations of SARS-CoV-2

Abstract:

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can affect any part of the neuraxis. Many neurological conditions have been attributed to be caused by SARS-CoV-2, namely encephalopathy (acute necrotizing encephalopathy and encephalopathy with reversible splenial lesions), seizures, stroke, cranial nerve palsies, meningoencephalitis, acute disseminated encephalomyelitis (ADEM), transverse myelitis (long and short segment), Guillain-Barré syndrome (GBS) and its variants, polyneuritis cranialis, optic neuritis (ON), plexopathy, myasthenia gravis (MG), and myositis.

The pathophysiology differs depending on the time frame of presentation. In patients with concomitant pulmonary disease, for instance, acute neurological illness appears to be caused by endotheliopathy and cytokine storm. Autoimmunity and molecular mimicry are causative for post-coronavirus disease 2019 (COVID-19)-sequelae. It has not yet been shown that the virus can penetrate the central nervous system (CNS) directly.

This review aims to describe the disease and root pathogenic cause of the various neurological manifestations of COVID-19. We searched Pubmed/Medline and Google Scholar using the keywords “SARS-CoV-2” and “neurological illness” for articles published between January 2020 and November 2022. Then, we used the SWIFT-Review (Sciome LLC, North Carolina, United States), a text-mining workbench for systematic review, to classify the 1383 articles into MeSH hierarchical tree codes for articles on various parts of the nervous system, such as the CNS, peripheral nervous system, autonomic nervous system, neuromuscular junction, sensory system, and musculoskeletal system. Finally, we reviewed 152 articles in full text. SARS-CoV-2 RNA has been found in multiple brain areas without any histopathological changes.

Despite the absence of in vivo virions or virus-infected cells, CNS inflammation has been reported, especially in the olfactory bulb and brain stem. SARS-CoV-2 genomes and proteins have been found in affected individuals’ brain tissues, but corresponding neuropathologic changes are seldom found in these cases. Additionally, viral RNA can rarely be identified in neurological patients’ CSF post hoc SARS-CoV-2 infection.

Most patients with neurological symptoms do not have active viral replication in the nervous system and infrequently have typical clinical and laboratory characteristics of viral CNS infections. Endotheliopathy and the systemic inflammatory response to SARS-CoV-2 infection play a crucial role in developing neuro-COVID-19, with proinflammatory cytokine release mediating both pathological pathways. The systemic inflammatory mediators likely activate astrocytes and microglia across the blood-brain barrier, indirectly affecting CNS-specific immune activation and tissue injury. The management differs according to co-morbidities and the neurological disorder.

Source: P, Sehgal V, Kapila S, et al. (April 27, 2023) Review of Neurological Manifestations of SARS-CoV-2. Cureus 15(4): e38194. doi:10.7759/cureus.38194 https://www.cureus.com/articles/149269-review-of-neurological-manifestations-of-sars-cov-2#!/ (Full text)

Proteomics and cytokine analyses distinguish myalgic encephalomyelitis/chronic fatigue syndrome cases from controls

Abstract:

Background: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex, heterogenous disease characterized by unexplained persistent fatigue and other features including cognitive impairment, myalgias, post-exertional malaise, and immune system dysfunction. Cytokines are present in plasma and encapsulated in extracellular vesicles (EVs), but there have been only a few reports of EV characteristics and cargo in ME/CFS. Several small studies have previously described plasma proteins or protein pathways that are associated with ME/CFS.

Methods: We prepared extracellular vesicles (EVs) from frozen plasma samples from a cohort of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) cases and controls with prior published plasma cytokine and plasma proteomics data. The cytokine content of the plasma-derived extracellular vesicles was determined by a multiplex assay and differences between patients and controls were assessed. We then performed multi-omic statistical analyses that considered not only this new data, but extensive clinical data describing the health of the subjects.

Results: ME/CFS cases exhibited greater size and concentration of EVs in plasma. Assays of cytokine content in EVs revealed IL2 was significantly higher in cases. We observed numerous correlations among EV cytokines, among plasma cytokines, and among plasma proteins from mass spectrometry proteomics. Significant correlations between clinical data and protein levels suggest roles of particular proteins and pathways in the disease. For example, higher levels of the pro-inflammatory cytokines Granulocyte-Monocyte Colony-Stimulating Factor (CSF2) and Tumor Necrosis Factor (TNFα) were correlated with greater physical and fatigue symptoms in ME/CFS cases. Higher serine protease SERPINA5, which is involved in hemostasis, was correlated with higher SF-36 general health scores in ME/CFS. Machine learning classifiers were able to identify a list of 20 proteins that could discriminate between cases and controls, with XGBoost providing the best classification with 86.1% accuracy and a cross-validated AUROC value of 0.947. Random Forest distinguished cases from controls with 79.1% accuracy and an AUROC value of 0.891 using only 7 proteins.

Conclusions: These findings add to the substantial number of objective differences in biomolecules that have been identified in individuals with ME/CFS. The observed correlations of proteins important in immune responses and hemostasis with clinical data further implicates a disturbance of these functions in ME/CFS.

Source: Giloteaux L, Li J, Hornig M, Lipkin WI, Ruppert D, Hanson MR. Proteomics and cytokine analyses distinguish myalgic encephalomyelitis/chronic fatigue syndrome cases from controls. J Transl Med. 2023 May 13;21(1):322. doi: 10.1186/s12967-023-04179-3. PMID: 37179299. https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-04179-3 (Full text)

Cytokine deficiencies in patients with Long-COVID

Abstract:

Up to half of individuals who contract SARS-CoV-2 develop symptoms of long-COVID approximately three months after initial infection. These symptoms are highly variable, and the mechanisms inducing them are yet to be understood. We compared plasma cytokine levels from individuals with long-COVID to healthy individuals and found that those with long-COVID had 100% reductions in circulating levels of Interferon Gamma (IFNγ) and Interleukin-8 (IL-8). Additionally, we found significant reductions in levels of IL-6, IL-2, IL-17, IL-13, and IL-4 in individuals with long-COVID.

We propose immune exhaustion as the driver of long-COVID, with the complete absence of IFNγ and IL-8 preventing the lungs and other organs from healing after acute infection, and reducing the ability to fight off subsequent infections, both contributing to the myriad of symptoms suffered by those with long-COVID.

Source: Williams ES, Martins TB, Shah KS, Hill HR, Coiras M, Spivak AM, Planelles V. Cytokine Deficiencies in Patients with Long-COVID. J Clin Cell Immunol. 2022;13(6):672. Epub 2022 Nov 18. PMID: 36742994; PMCID: PMC9894377. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9894377/ (Full text)

High levels of pro-inflammatory SARS-CoV-2-specific biomarkers revealed by in vitro whole blood cytokine release assay (CRA) in recovered and long-COVID-19 patients

Abstract:

Background: Cytokines induced by SARS-CoV-2 infection play a crucial role in the pathophysiology of COVID-19 and hyperinflammatory responses have been associated with poor clinical outcomes, with progression to severe conditions or long-term subacute complications named as long-COVID-19.

Methods: In this cross-sectional study, we aimed to evaluate a set of antigen-specific inflammatory cytokines in blood from recovered COVID-19 individuals or who suffered a post-acute phase of SARS-CoV-2 infection compared to healthy individuals with no history of COVID-19 exposition or infection. Interferon-gamma (IFN-γ), IFN-γ-induced protein 10 (IP-10), tumor necrosis factor (TNF), IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, and IL-17A were quantified by multiplex cytometric bead assay and enzyme-linked immunosorbent assay after stimulation of whole blood with recombinant Spike protein from SARS-CoV-2. Additionally, all participants have evaluated for anti-(S) protein-specific IgG antibodies. Clinical specimens were collected within two months of COVID-19 diagnosis.

Results: A total of 47 individuals were enrolled in the study, a median age of 43 years (IQR = 14.5), grouped into healthy individuals with no history of infection or exposure to SARS-CoV-2 (unexposed group; N = 21); and patients from the Health Complex of the Rio de Janeiro State University (UERJ), Brazil, who were SARS-CoV-2 positive by RT-PCR (COVID-19 group)–categorized as recovered COVID-19 (N = 11) or long-COVID-19 (N = 15). All COVID-19 patients presented at least one signal or symptom during the first two weeks of infection. Six patients were hospitalized and required invasive mechanical ventilation.

Our results showed that COVID-19 patients had significantly higher levels of IFN-γ, TNF, IL-1β, IL-2, IL-6, IL-8, and IP-10 than the unexposed group. The long-COVID-19 group has presented significantly high levels of IL-1β and IL-6 compared to unexposed individuals, but not from recovered COVID-19. A principal-component analysis demonstrated 84.3% of the total variance of inflammatory-SARS-CoV-2 response in the first two components, and it was possible to stratify IL-6, TNF, IL-1β, IL-10, and IL-2 as the top-five cytokines which are candidates to discriminate COVID-19 group (including long-COVID-19 subgroup) and healthy unexposed individuals.

Conclusion: We revealed important S protein-specific differential biomarkers in individuals affected by COVID-19, bringing new insights into the inflammatory status or SARS-CoV-2 exposition determination.

Source: Gomes SMR, Brito ACdS, Manfro WFP, Ribeiro-Alves M, Ribeiro RSdA, da Cal MS, et al. (2023) High levels of pro-inflammatory SARS-CoV-2-specific biomarkers revealed by in vitro whole blood cytokine release assay (CRA) in recovered and long-COVID-19 patients. PLoS ONE 18(4): e0283983. https://doi.org/10.1371/journal.pone.0283983 (Full text)

Immunological dysfunction and mast cell activation syndrome in long COVID

Abstract:

At least 65 million people around the world suffer from long COVID, with the majority of cases occurring in the productive age (36–50 years old). Individuals with long COVID are confounded with multiple organ system dysfunctions, long-term organ injury sequelae, and a decreased quality of life. There is an overlapping of risk factors between long COVID and other postviral infection syndromes, so advances in research could also benefit other groups of patients.

Long COVID is the consequence of multiple immune system dysregulation, such as T-cell depletion, innate immune cell hyperactivity, lack of naive T and B cells, and elevated signature of pro-inflammatory cytokines, together with persistent SARS-CoV2 reservoir and other consequences of acute infection.

There is an activated condition of mast cells in long COVID, with abnormal granulation and excessive inflammatory cytokine release. A study by Weinstock et al. indicates that patients with long COVID suffer the same clinical syndrome as patients with mast cell activation syndrome (MCAS).

Diagnosis and treatment of MCAS in patients with long COVID will provide further symptomatic relief, and manage mast cell-mediated hyperinflammation states, which could be useful in the long-term control and recovery of such patients.

Source: Sumantri, Stevent; Rengganis, Iris. Immunological dysfunction and mast cell activation syndrome in long COVID. Asia Pacific Allergy ():10.5415/apallergy.0000000000000022, March 30, 2023. | DOI: 10.5415/apallergy.0000000000000022 https://journals.lww.com/apallergy/Fulltext/9900/Immunological_dysfunction_and_mast_cell_activation.2.aspx (Full text)

Role of the MicroRNAs in the Pathogenic Mechanism of Painful Symptoms in Long COVID: Systematic Review

Abstract:

The ongoing pandemic of COVID-19 has caused more than 6.7 million tragic deaths, plus, a large percentage of people who survived it present a myriad of chronic symptoms that last for at least 6 months; this has been named as long COVID. Some of the most prevalent are painful symptoms like headache, joint pain, migraine, neuropathic-like pain, fatigue and myalgia. MicroRNAs are small non-coding RNAs that regulate genes, and their involvement in several pathologies has been extensively shown. A deregulation of miRNAs has been observed in patients with COVID-19.
The objective of the present systematic review was to show the prevalence of chronic pain-like symptoms of patients with long COVID and based on the expression of miRNAs in patients with COVID-19, and to present a proposal on how they may be involved in the pathogenic mechanisms of chronic pain-like symptoms.
A systematic review was carried out in online databases for original articles published between March 2020 to April 2022; the systematic review followed the PRISMA guidelines, and it was registered in PROSPERO with registration number CRD42022318992. A total of 22 articles were included for the evaluation of miRNAs and 20 regarding long COVID; the overall prevalence of pain-like symptoms was around 10 to 87%, plus, the miRNAs that were commonly up and downregulated were miR-21-5p, miR-29a,b,c-3p miR-92a,b-3p, miR-92b-5p, miR-126-3p, miR-150-5p, miR-155-5p, miR-200a, c-3p, miR-320a,b,c,d,e-3p, and miR-451a.
The molecular pathways that we hypothesized to be modulated by these miRNAs are the IL-6/STAT3 proinflammatory axis and the compromise of the blood–nerve barrier; these two mechanisms could be associated with the prevalence of fatigue and chronic pain in the long COVID population, plus they could be novel pharmacological targets in order to reduce and prevent these symptoms.
Source: Reyes-Long S, Cortés-Altamirano JL, Bandala C, Avendaño-Ortiz K, Bonilla-Jaime H, Bueno-Nava A, Ávila-Luna A, Sánchez-Aparicio P, Clavijo-Cornejo D, Dotor-LLerena AL, Cabrera-Ruiz E, Alfaro-Rodríguez A. Role of the MicroRNAs in the Pathogenic Mechanism of Painful Symptoms in Long COVID: Systematic Review. International Journal of Molecular Sciences. 2023; 24(4):3574. https://doi.org/10.3390/ijms24043574 https://www.mdpi.com/1422-0067/24/4/3574 (Full text)