Tag: long covid immunology

Thrombophilia and Immune-Related Genetic Markers in Long COVID

Abstract:

Aiming to evaluate the role of ten functional polymorphisms in long COVID, involved in major inflammatory, immune response and thrombophilia pathways, a cross-sectional sample composed of 199 long COVID (LC) patients and a cohort composed of 79 COVID-19 patients whose follow-up by over six months did not reveal any evidence of long COVID (NLC) were investigated to detect genetic susceptibility to long COVID.
Ten functional polymorphisms located in thrombophilia-related and immune response genes were genotyped by real time PCR. In terms of clinical outcomes, LC patients presented higher prevalence of heart disease as preexistent comorbidity. In general, the proportions of symptoms in acute phase of the disease were higher among LC patients.
The genotype AA of the interferon gamma (IFNG) gene was observed in higher frequency among LC patients (60%; p = 0.033). Moreover, the genotype CC of the methylenetetrahydrofolate reductase (MTHFR) gene was also more frequent among LC patients (49%; p = 0.045). Additionally, the frequencies of LC symptoms were higher among carriers of IFNG genotypes AA than among non-AA genotypes (Z = 5.08; p < 0.0001).
Two polymorphisms were associated with LC in both inflammatory and thrombophilia pathways, thus reinforcing their role in LC. The higher frequencies of acute phase symptoms among LC and higher frequency of underlying comorbidities might suggest that acute disease severity and the triggering of preexisting condition may play a role in LC development.
Source: da Silva R, de Sarges KML, Cantanhede MHD, da Costa FP, dos Santos EF, Rodrigues FBB, de Nazaré do Socorro de Almeida Viana M, de Meira Leite M, da Silva ALS, de Brito MTM, da Silva Torres MK, Queiroz MAF, Vallinoto IMVC, Henriques DF, dos Santos CP, Viana GMR, Quaresma JAS, Falcão LFM, Vallinoto ACR, dos Santos EJM. Thrombophilia and Immune-Related Genetic Markers in Long COVID. Viruses. 2023; 15(4):885. https://doi.org/10.3390/v15040885 https://www.mdpi.com/1999-4915/15/4/885 (Full text)

Long COVID in autoimmune rheumatic diseases

Abstract:

Consequences of Corona Virus Disease-19 (COVID-19) in patients with rheumatic diseases (RDs) are clinically diverse. SARS-CoV-2 infection has been associated with various autoimmune and rheumatic manifestations over the past three years. Emerging evidence points to the possibility of Long COVID predisposition in rheumatic patients due to the changes in immune regulatory response. The aim of this article was to overview data on the pathobiology of Long COVID in patients with RDs.

Related risk factors, clinical characteristics, and prognosis of Long COVID in RDs were analyzed. Relevant articles were retrieved from Medline/PubMed, Scopus, and Directory of Open Access Journals (DOAJ). Diverse mechanisms of viral persistence, chronic low-grade inflammation, lasting production of autoantibodies, endotheliopathy, vascular complications, and permanent tissue damage have been described in association with Long COVID. Patients with RDs who survive COVID-19 often experience severe complications due to the immune disbalance resulting in multiple organ damage. Regular monitoring and treatment are warranted in view of the accumulating evidence.

Source: Fedorchenko Y, Zimba O. Long COVID in autoimmune rheumatic diseases. Rheumatol Int. 2023 Mar 30:1–11. doi: 10.1007/s00296-023-05319-0. Epub ahead of print. PMID: 36995436; PMCID: PMC10061411. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10061411/ (Full text)

Para-infectious brain injury in COVID-19 persists at follow-up despite attenuated cytokine and autoantibody responses

Abstract:

We measured brain injury markers, inflammatory mediators, and autoantibodies in 203 participants with COVID-19; 111 provided acute sera (1-11 days post admission) and 56 with COVID-19-associated neurological diagnoses provided subacute/convalescent sera (6-76 weeks post-admission).

Compared to 60 controls, brain injury biomarkers (Tau, GFAP, NfL, UCH-L1) were increased in acute sera, significantly more so for NfL and UCH-L1, in patients with altered consciousness. Tau and NfL remained elevated in convalescent sera, particularly following cerebrovascular and neuroinflammatory disorders. Acutely, inflammatory mediators (including IL-6, IL-12p40, HGF, M-CSF, CCL2, and IL-1RA) were higher in participants with altered consciousness, and correlated with brain injury biomarker levels. Inflammatory mediators were lower than acute levels in convalescent sera, but levels of CCL2, CCL7, IL-1RA, IL-2Rα, M-CSF, SCF, IL-16 and IL-18 in individual participants correlated with Tau levels even at this late time point.

When compared to acute COVID-19 patients with a normal GCS, network analysis showed significantly altered immune responses in patients with acute alteration of consciousness, and in convalescent patients who had suffered an acute neurological complication. The frequency and range of autoantibodies did not associate with neurological disorders. However, autoantibodies against specific antigens were more frequent in patients with altered consciousness in the acute phase (including MYL7, UCH-L1, GRIN3B, and DDR2), and in patients with neurological complications in the convalescent phase (including MYL7, GNRHR, and HLA antigens).

In a novel low-inoculum mouse model of SARS-CoV-2, while viral replication was only consistently seen in mouse lungs, inflammatory responses were seen in both brain and lungs, with significant increases in CCL4, IFNγ, IL-17A, and microglial reactivity in the brain. Neurological injury is common in the acute phase and persists late after COVID-19, and may be driven by a para-infectious process involving a dysregulated host response.

Source: Benedict D. Michael, Cordelia Dunai, Edward J. Needham, Kukatharmini Tharmaratnam, Robyn Williams, Yun Huang, Sarah A. Boardman, Jordan Clark, Parul Sharma, Krishanthi Subramaniam, Greta K. Wood, Ceryce Collie, Richard Digby, Alexander Ren, Emma Norton, Maya Leibowitz, Soraya Ebrahimi, Andrew Fower, Hannah Fox, Esteban Tato, Mark Ellul, Geraint Sunderland, Marie Held, Claire Hetherington, Franklyn Nkongho, Alish Palmos, Alexander Grundmann, James P. Stewart, Michael Griffiths, Tom Solomon, Gerome Breen, Alasdair Coles, Jonathan Cavanagh, Sarosh R. Irani, Angela Vincent, Leonie Taams, David K. Menon. Para-infectious brain injury in COVID-19 persists at follow-up despite attenuated cytokine and autoantibody responses. medRxiv 2023.04.03.23287902; doi: https://doi.org/10.1101/2023.04.03.23287902 (Full text available as PDF file)

Incident autoimmune diseases in association with a SARS-CoV-2 infection: A matched cohort study

Abstract:

Objectives To investigate whether the risk of developing an incident autoimmune disease is increased in patients with previous COVID-19 disease compared to people without COVID-19.

Method A cohort was selected from German routine health care data covering 38.9 million individuals. Based on documented diagnoses, we identified individuals with polymerase chain reaction (PCR)-confirmed COVID-19 through December 31, 2020. Patients were matched 1:3 to control patients without COVID-19. Both groups were followed up until June 30, 2021. We used the four quarters preceding the index date until the end of follow-up to analyze the onset of autoimmune diseases during the post-acute period. Incidence rates (IR) per 1000 person-years were calculated for each outcome and patient group. Poisson models were deployed to estimate the incidence rate ratios (IRRs) of developing an autoimmune disease conditional on a preceding diagnosis of COVID-19.

Results In total, 641,704 patients with COVID-19 were included. Comparing the incidence rates in the COVID-19 (IR=15.05, 95% CI: 14.69-15.42) and matched control groups (IR=10.55, 95% CI: 10.25-10.86), we found a 42.63% higher likelihood of acquiring autoimmunity for patients who had suffered from COVID-19. This estimate was similar for common autoimmune diseases, such as Hashimoto thyroiditis, rheumatoid arthritis, or Sjögren syndrome. The highest IRR was observed for autoimmune disease of the vasculitis group. Patients with a more severe course of COVID-19 were at a greater risk for incident autoimmune diseases.

Conclusions SARS-CoV-2 infection is associated with an increased risk of developing new-onset autoimmune diseases after the acute phase of infection.

Source: Falko Tesch, Franz Ehm, Annika Vivirito, Danny Wende, Manuel Batram, Friedrich Loser, Simone Menzer, Josephine Jacob, Martin Roessler, Martin Seifert, Barbara Kind, Christina König, Claudia Schulte, Tilo Buschmann, Dagmar Hertle, Pedro Ballesteros, Stefan Baßler, Barbara Bertele, Thomas Bitterer, Cordula Riederer, Franziska Sobik, Lukas Reitzle, Christa Scheidt-Nave, Jochen Schmitt. Incident autoimmune diseases in association with a SARS-CoV-2 infection: A matched cohort study. medRxiv 2023.01.25.23285014; doi:https://doi.org/10.1101/2023.01.25.23285014 (Full text)

The original strain of SARS-CoV-2, the Delta variant, and the Omicron variant infect microglia efficiently, in contrast to their inability to infect neurons: Analysis using 2D and 3D cultures

Highlights:

  • None of the SARS-CoV-2 original, delta, or omicron strains can infect neurons.
  • The SARS-CoV-2 original, delta, and omicron strains can infect microglia.
  • The CNS cells differentiated from hiPSCs are useful to investigate the infectivity of the virus.

Abstract:

COVID-19 causes neurological damage, systemic inflammation, and immune cell abnormalities. COVID-19-induced neurological impairment may be caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which directly infects cells of the central nervous system (CNS) and exerts toxic effects. Furthermore, SARS-CoV-2 mutations occur constantly, and it is not well understood how the infectivity of the virus to cells of the CNS changes as the virus mutates.

Few studies have examined whether the infectivity of cells of CNS – neural stem/progenitor cells (NS/PCs), neurons, astrocytes, and microglia – varies among SARS-CoV-2 mutant strains. In this study, therefore, we investigated whether SARS-CoV-2 mutations increase infectivity to CNS cells, including microglia.

Since it was essential to demonstrate the infectivity of the virus to CNS cells in vitro using human cells, we generated cortical neurons, astrocytes, and microglia from human induced pluripotent stem cells (hiPSCs). We added pseudotyped lentiviruses of SARS-CoV-2 to each type of cells, and then we examined their infectivity. We prepared three pseudotyped lentiviruses expressing the S protein of the original strain (the first SARS-CoV-2 discovered in the world), the Delta variant, and the Omicron variant on their envelopes and analyzed differences of their ability to infect CNS cells. We also generated brain organoids and investigated the infectivity of each virus.

The viruses did not infect cortical neurons, astrocytes, or NS/PCs, but microglia were infected by the original, Delta, and Omicron pseudotyped viruses. In addition, DPP4 and CD147, potential core receptors of SARS-CoV-2, were highly expressed in the infected microglia, while DPP4 expression was deficient in cortical neurons, astrocytes, and NS/PCs.

Our results suggest that DPP4, which is also a receptor for Middle East respiratory syndrome-coronavirus (MERS-CoV), may play an essential role in the CNS. Our study is applicable to the validation of the infectivity of viruses that cause various infectious diseases in CNS cells, which are difficult to sample from humans.

Source: Kase Y, Sonn I, Goto M, Murakami R, Sato T, Okano H. The original strain of SARS-CoV-2, the Delta variant, and the Omicron variant infect microglia efficiently, in contrast to their inability to infect neurons: Analysis using 2D and 3D cultures. Exp Neurol. 2023 Mar 11;363:114379. doi: 10.1016/j.expneurol.2023.114379. Epub ahead of print. PMID: 36914084; PMCID: PMC10008041. https://www.sciencedirect.com/science/article/pii/S0014488623000638?via%3Dihub (Full text)

Regulatory T Cells (Tregs) and COVID-19: Unveiling the Mechanisms, and Therapeutic Potentialities with a Special Focus on Long COVID

Abstract:

The COVID-19 pandemic has caused havoc all around the world. The causative agent of COVID-19 is the novel form of the coronavirus (CoV) named SARS-CoV-2, which results in immune system disruption, increased inflammation, and acute respiratory distress syndrome (ARDS). T cells have been important components of the immune system, which decide the fate of the COVID-19 disease. Recent studies have reported an important subset of T cells known as regulatory T cells (Tregs), which possess immunosuppressive and immunoregulatory properties and play a crucial role in the prognosis of COVID-19 disease.
Recent studies have shown that COVID-19 patients have considerably fewer Tregs than the general population. Such a decrement may have an impact on COVID-19 patients in a number of ways, including diminishing the effect of inflammatory inhibition, creating an inequality in the Treg/Th17 percentage, and raising the chance of respiratory failure. Having fewer Tregs may enhance the likelihood of long COVID development in addition to contributing to the disease’s poor prognosis.
Additionally, tissue-resident Tregs provide tissue repair in addition to immunosuppressive and immunoregulatory activities, which may aid in the recovery of COVID-19 patients. The severity of the illness is also linked to abnormalities in the Tregs’ phenotype, such as reduced expression of FoxP3 and other immunosuppressive cytokines, including IL-10 and TGF-beta.
Hence, in this review, we summarize the immunosuppressive mechanisms and their possible roles in the prognosis of COVID-19 disease. Furthermore, the perturbations in Tregs have been associated with disease severity. The roles of Tregs are also explained in the long COVID. This review also discusses the potential therapeutic roles of Tregs in the management of patients with COVID-19.
Source: Dhawan M, Rabaan AA, Alwarthan S, Alhajri M, Halwani MA, Alshengeti A, Najim MA, Alwashmi ASS, Alshehri AA, Alshamrani SA, AlShehail BM, Garout M, Al-Abdulhadi S, Al-Ahmed SH, Thakur N, Verma G. Regulatory T Cells (Tregs) and COVID-19: Unveiling the Mechanisms, and Therapeutic Potentialities with a Special Focus on Long COVID. Vaccines. 2023; 11(3):699. https://doi.org/10.3390/vaccines11030699 https://www.mdpi.com/2076-393X/11/3/699 (Full text)

Immunometabolic rewiring in long COVID patients with chronic headache

Abstract:

Almost 20% of patients with COVID-19 experience long-term effects, known as post-COVID condition or long COVID. Among many lingering neurologic symptoms, chronic headache is the most common. Despite this health concern, the etiology of long COVID headache is still not well characterized. Here, we present a longitudinal multi-omics analysis of blood leukocyte transcriptomics, plasma proteomics and metabolomics of long COVID patients with chronic headache. L

ong COVID patients experienced a state of hyper-inflammation prior to chronic headache onset and maintained persistent inflammatory activation throughout the progression of chronic headache. Metabolomic analysis also revealed augmented arginine and lipid metabolisms, skewing towards a nitric oxide-based pro-inflammation. Furthermore, metabolisms of neurotransmitters including serotonin, dopamine, glutamate, and GABA were markedly dysregulated during the progression of long COVID headache.

Overall, these findings illustrate the immuno-metabolomics landscape of long COVID patients with chronic headache, which may provide insights to potential therapeutic interventions.

Source: Foo SS, Chen W, Jung KL, Azamor T, Choi UY, Zhang P, Comhair SA, Erzurum SC, Jehi L, Jung JU. Immunometabolic rewiring in long COVID patients with chronic headache. bioRxiv [Preprint]. 2023 Mar 6:2023.03.06.531302. doi: 10.1101/2023.03.06.531302. PMID: 36945569; PMCID: PMC10028820. https://www.biorxiv.org/content/10.1101/2023.03.06.531302v1.full (Full text)

Autoimmunity in Long Covid and POTS

Abstract:

Orthostatic intolerance and other autonomic dysfunction syndromes are emerging as distinct symptom clusters in Long Covid. Often accompanying these are common, multi-system constitutional features such as fatigue, malaise and skin rashes which can signify generalised immune dysregulation. At the same time, multiple autoantibodies are identified in both Covid-related autonomic disorders and non-Covid autonomic disorders, implying a possible underlying autoimmune pathology. The lack of specificity of these findings precludes direct interpretations of cause and association, but prevalence with its supporting evidence is compelling.

In this review, we discuss the role of the autonomic nervous and immune systems in Covid and Long Covid and their potential influence on symptoms and clinical practice. Additionally, overlap with non-Covid autonomic dysfunction is considered. Understanding these new disorders can inform both neuro-immunology and Long Covid management.

Source: Fatema-Zahra El-Rhermoul, Artur Fedorowski, Philip Eardley, Patricia Taraborrelli, Dimitrios Panagopoulos, Richard Sutton, Phang Boon Lim, Melanie Dani, Autoimmunity in Long Covid and POTS, Oxford Open Immunology, 2023;, iqad002, https://doi.org/10.1093/oxfimm/iqad002 (Full text available as PDF file)

Monocyte migration profiles define disease severity in acute COVID-19 and unique features of long COVID

Abstract:

Background: COVID-19 is associated with a dysregulated immune response but it is unclear how immune dysfunction contributes to the chronic morbidity persisting in many COVID-19 patients during convalescence (long COVID).

Methods: We assessed phenotypical and functional changes of monocytes in COVID-19 patients during hospitalization and up to 9 months of convalescence following COVID-19, respiratory syncytial virus (RSV) or influenza A (flu). Progressive fibrosing interstitial lung disease (PFILD) patients were included a positive control for severe, ongoing lung injury.

Results: Monocyte alterations in acute COVID-19 patients included aberrant expression of leucocyte migration molecules, continuing into convalescence (n=142) and corresponding to specific symptoms of long COVID. Long COVID patients with unresolved lung injury, indicated by sustained shortness of breath and abnormal chest radiology, were defined by high monocyte expression of chemokine receptor CXCR6 (p<0.0001) and adhesion molecule PSGL-1 (p<0.01), alongside preferential migration of monocytes towards CXCR6 ligand CXCL16 (p<0.05) which is abundantly expressed in the lung. Monocyte CXCR6 and lung CXCL16 were heightened in PFILD patients (p<0.001) confirming a role for the CXCR6-CXCL16 axis in ongoing lung injury. Conversely, monocytes from long COVID patients with ongoing fatigue exhibited sustained reduction of the prostaglandin-generating enzyme COX-2 (p<0.01) and CXCR2 expression (p<0.05). These monocyte changes were not present in RSV or flu convalescence.

Conclusions: Our data define unique monocyte signatures that define subgroups of long COVID patients, indicating a key role for monocyte migration in COVID-19 pathophysiology. Targeting these pathways may provide novel therapeutic opportunities in COVID-19 patients with persistent morbidity.

Source: Scott NA, Pearmain L, Knight SB, Brand O, Morgan DJ, Jagger C, Harbach S, Khan S, Shuwa HA, Franklin M, Kästele V, Williams T, Prise I, McClure FA, Hackney P, Smith L, Menon M, Konkel JE, Lawless C, Wilson J, Mathioudakis AG, Stanel SC, Ustianowski A, Lindergard G, Brij S, Diar Bakerly N, Dark P, Brightling C, Rivera-Ortega P, Lord GM, Horsley A; CIRCO; Piper Hanley K, Felton T, Simpson A, Grainger JR, Hussell T, Mann ER. Monocyte migration profiles define disease severity in acute COVID-19 and unique features of long COVID. Eur Respir J. 2023 Mar 15:2202226. doi: 10.1183/13993003.02226-2022. Epub ahead of print. PMID: 36922030. https://erj.ersjournals.com/content/early/2023/02/23/13993003.02226-2022 (Full article available as PDF file)

Pathogenesis Underlying Neurological Manifestations of Long COVID Syndrome and Potential Therapeutics

Abstract:

The development of long-term symptoms of coronavirus disease 2019 (COVID-19) more than four weeks after primary infection, termed “long COVID” or post-acute sequela of COVID-19 (PASC), can implicate persistent neurological complications in up to one third of patients and present as fatigue, “brain fog”, headaches, cognitive impairment, dysautonomia, neuropsychiatric symptoms, anosmia, hypogeusia, and peripheral neuropathy. Pathogenic mechanisms of these symptoms of long COVID remain largely unclear; however, several hypotheses implicate both nervous system and systemic pathogenic mechanisms such as SARS-CoV2 viral persistence and neuroinvasion, abnormal immunological response, autoimmunity, coagulopathies, and endotheliopathy.
Outside of the CNS, SARS-CoV-2 can invade the support and stem cells of the olfactory epithelium leading to persistent alterations to olfactory function. SARS-CoV-2 infection may induce abnormalities in innate and adaptive immunity including monocyte expansion, T-cell exhaustion, and prolonged cytokine release, which may cause neuroinflammatory responses and microglia activation, white matter abnormalities, and microvascular changes. Additionally, microvascular clot formation can occlude capillaries and endotheliopathy, due to SARS-CoV-2 protease activity and complement activation, can contribute to hypoxic neuronal injury and blood–brain barrier dysfunction, respectively.
Current therapeutics target pathological mechanisms by employing antivirals, decreasing inflammation, and promoting olfactory epithelium regeneration. Thus, from laboratory evidence and clinical trials in the literature, we sought to synthesize the pathophysiological pathways underlying neurological symptoms of long COVID and potential therapeutics.
Source: Leng A, Shah M, Ahmad SA, Premraj L, Wildi K, Li Bassi G, Pardo CA, Choi A, Cho S-M. Pathogenesis Underlying Neurological Manifestations of Long COVID Syndrome and Potential Therapeutics. Cells. 2023; 12(5):816. https://doi.org/10.3390/cells12050816 (Full text)