The persistent viral infections in the development and severity of myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

Background: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a multifactorial disease with an unexplained aetiology in which viral infections are possible trigger factors. The aim of this study was to determine the involvement of human herpesvirus (HHV)-6A/B, HHV-7, and parvovirus B19 (B19V) in the etiopathogenesis of ME/CFS.

Methods: 200 patients with clinically diagnosed ME/CFS and 150 apparently healthy individuals were enrolled in this study. Single-round, nested, and quantitative real-time polymerase chain reactions (PCR) were used to detect the presence and load of HHV-6A/B, HHV-7, and B19V. HHV-6A and HHV-6B were distinguished by PCR and restriction analysis. Immunoenzymatic assays were applied to estimate the presence of virus-specific antibodies and the level of cytokines.

Results: HHV-6A/B, HHV-7, and B19V specific antibodies were detected among patients and healthy individuals in 92.1% and 76.7%, 84.6% and 93.8%, and 78% and 67.4% of cases. HHV-6B had 99% of HHV-6 positive patients. Latent HHV-6A/B, HHV-7, and B19V infection/co-infection was observed in 51.5% of the patients and 76.7% of the healthy individuals, whereas active-45% of the ME/CFS patients and 8.7% of healthy individuals. HHV-6A/B load in patients with a persistent infection/co-infection in a latent and active phase was 262 and 653.2 copies/106 cells, whereas HHV-7 load was 166.5 and 248.5 copies/106 cells, and B19V-96.8 and 250.8 copies/106 cells, respectively. ME/CFS patients with persistent infection in an active phase had a higher level of pro-inflammatory cytokines (interleukin(IL)-6, tumor necrosis factor-alpha(TNF-α) and IL-12) and anti-inflammatory (IL-10) than with a persistent infection in a latent phase. A significant difference was revealed in the levels of TNF-α, IL-12, and IL-10 among the patient groups without infection, with latent infection/co-infection, active single, double and triple co-infection. The levels of TNF-α, IL-12, and IL-10 are significantly higher in patients with severe compared with a moderate course of ME/CFS.

Conclusions: Significantly more persistent HHV-6A/B, HHV-7, and B19V infection/co-infection in an active phase with a higher viral load and elevated levels of pro- and anti-inflammatory cytokines among patients with ME/CFS than healthy individuals indicate the importance of these infections/co-infections in ME/CFS development. The presence of these infections/co-infections influences the ME/CFS clinical course severity.

Source: Rasa-Dzelzkaleja S, Krumina A, Capenko S, Nora-Krukle Z, Gravelsina S, Vilmane A, Ievina L, Shoenfeld Y, Murovska M; VirA project. The persistent viral infections in the development and severity of myalgic encephalomyelitis/chronic fatigue syndrome. J Transl Med. 2023 Jan 18;21(1):33. doi: 10.1186/s12967-023-03887-0. PMID: 36653846. https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03887-0 (Full text)

Kynurenine serves as useful biomarker in acute, Long- and Post-COVID-19 diagnostics

Abstract:

Introduction: In patients with SARS-CoV-2, innate immunity is playing a central role, depicted by hyperinflammation and longer lasting inflammatory response. Reliable inflammatory markers that cover both acute and long-lasting COVID-19 monitoring are still lacking. Thus, we investigated one specific inflammatory marker involved as one key player of the immune system, kynurenine (Kyn), and its use for diagnosis/detection of the Long-/Post-COVID syndrome in comparison to currently used markers in both serum and saliva samples.

Material and methods: The study compromised in total 151 inpatients with a SARS-CoV-2 infection hospitalized between 03/2020 and 09/2021. The group NC (normal controls) included blood bank donors (n=302, 144f/158m, mean age 47.1 ± 18.3 years (range 18-75)). Two further groups were generated based on Group A (n=85, 27f/58m, mean age 63.1 ± 18.3 years (range 19-90), acute admission to the hospital) and Group B (n=66, 22f/44m, mean age 66.6 ± 17.6 years (range 17-90), admitted either for weaning or for rehabilitation period due to Long-COVID symptoms/syndrome). Plasma concentrations of Kyn, C-Reactive Protein (CRP) and interleukin-6 (IL-6) were measured on admission. In Group B we determined Kyn 4 weeks after the negative PCR-test. In a subset of patients (n=11) concentrations of Kyn and CRP were measured in sera and saliva two, three and four months after dismission. We identified 12 patients with Post-COVID symptoms >20 weeks with still significant elevated Kyn-levels.

Results: Mean values for NC used as reference were 2.79 ± 0.61 µM, range 1.2-4.1 µM. On admission, patients showed significantly higher concentrations of Kyn compared to NC (p-values < 0.001). Kyn significantly correlated with IL-6 peak-values (r=0.411; p-values <0.001) and CRP (r=0.488, p-values<0.001). Kyn values in Group B (Long-/Post-COVID) showed still significant higher values (8.77 ± 1.72 µM, range 5.5-16.6 µM), whereas CRP values in Group B were in the normal range.

Conclusion: Serum and saliva Kyn are reflecting the acute and long-term pathophysiology of the SARS-CoV-2 disease concerning the innate immune response and thus may serve a useful biomarker for diagnosis and monitoring both Long- and Post-COVID syndrome and its therapy.

Source: Bizjak DA, Stangl M, Börner N, Bösch F, Durner J, Drunin G, Buhl JL, Abendroth D. Kynurenine serves as useful biomarker in acute, Long- and Post-COVID-19 diagnostics. Front Immunol. 2022 Sep 23;13:1004545. doi: 10.3389/fimmu.2022.1004545. PMID: 36211365; PMCID: PMC9537769. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9537769/ (Full text)

Neurogenesis is disrupted in human hippocampal progenitor cells upon exposure to serum samples from hospitalized COVID-19 patients with neurological symptoms

Abstract:

Coronavirus disease 2019 (COVID-19), represents an enormous new threat to our healthcare system and particularly to the health of older adults. Although the respiratory symptoms of COVID-19 are well recognized, the neurological manifestations, and their underlying cellular and molecular mechanisms, have not been extensively studied yet. Our study is the first one to test the direct effect of serum from hospitalised COVID-19 patients on human hippocampal neurogenesis using a unique in vitro experimental assay with human hippocampal progenitor cells (HPC0A07/03 C). We identify the different molecular pathways activated by serum from COVID-19 patients with and without neurological symptoms (i.e., delirium), and their effects on neuronal proliferation, neurogenesis, and apoptosis.

We collected serum sample twice, at time of hospital admission and approximately 5 days after hospitalization. We found that treatment with serum samples from COVID-19 patients with delirium (n = 18) decreased cell proliferation and neurogenesis, and increases apoptosis, when compared with serum samples of sex- and age-matched COVID-19 patients without delirium (n = 18). This effect was due to a higher concentration of interleukin 6 (IL6) in serum samples of patients with delirium (mean ± SD: 229.9 ± 79.1 pg/ml, vs. 32.5 ± 9.5 pg/ml in patients without delirium).

Indeed, treatment of cells with an antibody against IL6 prevented the decreased cell proliferation and neurogenesis and the increased apoptosis. Moreover, increased concentration of IL6 in serum samples from delirium patients stimulated the hippocampal cells to produce IL12 and IL13, and treatment with an antibody against IL12 or IL13 also prevented the decreased cell proliferation and neurogenesis, and the increased apoptosis. Interestingly, treatment with the compounds commonly administered to acute COVID-19 patients (the Janus kinase inhibitors, baricitinib, ruxolitinib and tofacitinib) were able to restore normal cell viability, proliferation and neurogenesis by targeting the effects of IL12 and IL13.

Overall, our results show that serum from COVID-19 patients with delirium can negatively affect hippocampal-dependent neurogenic processes, and that this effect is mediated by IL6-induced production of the downstream inflammatory cytokines IL12 and IL13, which are ultimately responsible for the detrimental cellular outcomes.

Source: Borsini, A., Merrick, B., Edgeworth, J. et al. Neurogenesis is disrupted in human hippocampal progenitor cells upon exposure to serum samples from hospitalized COVID-19 patients with neurological symptoms. Mol Psychiatry (2022). https://doi.org/10.1038/s41380-022-01741-1  (Full text)

Epipharyngeal Abrasive Therapy (EAT) Reduces the mRNA Expression of Major Proinflammatory Cytokine IL-6 in Chronic Epipharyngitis

Abstract:

The epipharynx, located behind the nasal cavity, is responsible for upper respiratory tract immunity; however, it is also the site of frequent acute and chronic inflammation. Previous reports have suggested that chronic epipharyngitis is involved not only in local symptoms such as cough and postnasal drip, but also in systemic inflammatory diseases such as IgA nephropathy and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and Long COVID.

Epipharyngeal Abrasive Therapy (EAT), which is an effective treatment for chronic epipharyngitis in Japan, is reported to be effective for these intractable diseases. The sedation of chronic epipharyngitis by EAT induces suppression of the inflammatory cytokines and improves systemic symptoms, which is considered to be one of the mechanisms, but there is no report that has proved this hypothesis. The purpose of this study was to clarify the anti-inflammatory effect of EAT histologically.

The study subjects were 8 patients who were not treated with EAT and 11 patients who were treated with EAT for chronic epipharyngitis for 1 month or more. For immunohistochemical assessment, the expression pattern of IL-6 mRNA, which plays a central role in the human cytokine network, was analyzed using in situ hybridization. The expression of IL-6 in the EAT-treated group was significantly lower than those in the EAT nontreated group (p = 0.0015). In addition, EAT suppressed the expression of tumor necrosis factor alpha (TNFα), a crucial proinflammatory cytokine. As a result, continuous EAT suppressed submucosal cell aggregation and reduced inflammatory cytokines. Thus, EAT may contribute to the improvement of systemic inflammatory diseases through the suppression of IL-6 expression.

Source: Nishi K, Yoshimoto S, Nishi S, Nishi T, Nishi R, Tanaka T, Tsunoda T, Imai K, Tanaka H, Hotta O, Tanaka A, Hiromatsu K, Shirasawa S, Nakagawa T, Yamano T. Epipharyngeal Abrasive Therapy (EAT) Reduces the mRNA Expression of Major Proinflammatory Cytokine IL-6 in Chronic Epipharyngitis. Int J Mol Sci. 2022 Aug 16;23(16):9205. doi: 10.3390/ijms23169205. PMID: 36012469; PMCID: PMC9409341. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9409341/ (Full text)

COVID-19 induces CNS cytokine expression and loss of hippocampal neurogenesis

Abstract:

Infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is associated with acute and postacute cognitive and neuropsychiatric symptoms including impaired memory, concentration, attention, sleep and affect. Mechanisms underlying these brain symptoms remain understudied.

Here we report that SARS-CoV-2-infected hamsters exhibit a lack of viral neuroinvasion despite aberrant blood-brain barrier permeability. Hamsters and patients deceased from coronavirus disease 2019 (COVID-19) also exhibit microglial activation and expression of interleukin (IL)-1β and IL-6, especially within the hippocampus and the medulla oblongata, when compared with non-COVID control hamsters and humans who died from other infections, cardiovascular disease, uraemia or trauma. In the hippocampal dentate gyrus of both COVID-19 hamsters and humans, we observed fewer neuroblasts and immature neurons.

Protracted inflammation, blood-brain barrier disruption and microglia activation may result in altered neurotransmission, neurogenesis and neuronal damage, explaining neuropsychiatric presentations of COVID-19. The involvement of the hippocampus may explain learning, memory and executive dysfunctions in COVID-19 patients.

Source: Soung AL, Vanderheiden A, Nordvig AS, Sissoko CA, Canoll P, Mariani MB, Jiang X, Bricker T, Rosoklija GB, Arango V, Underwood M, Mann JJ, Dwork AJ, Goldman JE, Boon ACM, Boldrini M, Klein RS. COVID-19 induces CNS cytokine expression and loss of hippocampal neurogenesis. Brain. 2022 Aug 25:awac270. doi: 10.1093/brain/awac270. Epub ahead of print. PMID: 36004663. https://academic.oup.com/brain/advance-article/doi/10.1093/brain/awac270/6672950?login=false  (Full text)

Cytokine Profiles Associated With Acute COVID-19 and Long COVID-19 Syndrome

Abstract:

The duration and severity of COVID-19 are related to age, comorbidities, and cytokine synthesis. This study evaluated the impact of these factors on patients with clinical presentations of COVID-19 in a Brazilian cohort.

A total of 317 patients diagnosed with COVID-19 were included; cases were distributed according to clinical status as severe (n=91), moderate (n=56) and mild (n=170). Of these patients, 92 had acute COVID-19 at sample collection, 90 had already recovered from COVID-19 without sequelae, and 135 had sequelae (long COVID syndrome).

In the acute COVID-19 group, patients with the severe form had higher IL-6 levels (p=0.0260). In the post-COVID-19 group, there was no significant difference in cytokine levels between groups with different clinical conditions. In the acute COVID-19 group, younger patients had higher levels of TNF-α, and patients without comorbidities had higher levels of TNF-α, IL-4 and IL-2 (p<0.05). In contrast, patients over age 60 with comorbidities had higher levels of IL-6. In the post-COVID-19 group, subjects with long COVID-19 had higher levels of IL-17 and IL-2 (p<0.05), and subjects without sequelae had higher levels of IL-10, IL-6 and IL- 4 (p<0.05).

Our results suggest that advanced age, comorbidities and elevated serum IL-6 levels are associated with severe COVID-19 and are good markers to differentiate severe from mild cases. Furthermore, high serum levels of IL-17 and IL-2 and low levels of IL-4 and IL-10 appear to constitute a cytokine profile of long COVID-19, and these markers are potential targets for COVID-19 treatment and prevention strategies.

Source: Queiroz MAF, Neves PFMD, Lima SS, Lopes JDC, Torres MKDS, Vallinoto IMVC, Bichara CDA, Dos Santos EF, de Brito MTFM, da Silva ALS, Leite MM, da Costa FP, Viana MNDSA, Rodrigues FBB, de Sarges KML, Cantanhede MHD, da Silva R, Bichara CNC, van den Berg AVS, Veríssimo AOL, Carvalho MDS, Henriques DF, Dos Santos CP, Nunes JAL, Costa IB, Viana GMR, Carneiro FRO, Palacios VRDCM, Quaresma JAS, Brasil-Costa I, Dos Santos EJM, Falcão LFM, Vallinoto ACR. Cytokine Profiles Associated With Acute COVID-19 and Long COVID-19 Syndrome. Front Cell Infect Microbiol. 2022 Jun 30;12:922422. doi: 10.3389/fcimb.2022.922422. PMID: 35846757; PMCID: PMC9279918. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9279918/ (Full text)

Spectrum of neurological manifestations among acute COVID-19 and long COVID-19 – A retrospective observational study

Abstract:

Objective. Preliminary clinical data indicate that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is associated with neurological symptoms. To compare the clinical features, imaging and treatments in patients with and without COVID 19. To compare the mortality and in-hospital stay among patients with and without COVID 19 and negative patients.

Materials and methods:In this retrospective, single-center study, we included all the patients who attended the department of neurology with neurologic symptoms with confirmed COVID-19 and long COVID-19 from June 2020 to January 2021. Data on clinical signs, diagnosis, laboratory findings were collected and analyzed from the records for positive patients and compared with neurologic patients without COVID-19 admitted in the same period.

Statistical analysis: The mean values between study groups were compared using an independent sample t-test and Mann Whitney u test. Categorical outcomes were compared using the Chi square test. Data was analyzed using coGuide software.

Results: Headache was the common neurologic manifestation present in COVID positive patients compared to COVID negative patients (39.13%). There was no statistically significant difference between the two groups in baseline parameters. Laboratory parameters like CRP, Serum Ferritin, LDH, D-dimer, ESR, and IL-6 showed a significant increase in COVID positive patients (P <0.05). In-hospital mortality was more in COVID positive patients than COVID negative patients (P <0.011).

Conclusion:The study showed varied neurologic symptoms in COVID patients, with headache as the common symptom. Hospital stay, morbidity, mortality, and inflammatory parameters were more in COVID positive patients compared to COVID negative patients.

Source: Pooja Dugani, Anish Mehta, Sunil V Furtado, R. Pradeep, Mahendra Javali, Purushottam Acharya, Vijayashree Thyagaraj, R. Srinivasa. Spectrum of neurological manifestations among acute COVID-19 and long COVID-19 – A retrospective observational study. Ref: Ro J Neurol. 2022;21(2) DOI: 10.37897/RJN.2021.2.14.  https://rjn.com.ro/articles/2022.2/RJN_2022_2_Art-14.pdf (Full text)

SARS-CoV-2-specific T cells associate with inflammation and reduced lung function in pulmonary post-acute sequalae of SARS-CoV-2

Abstract:

As of January 2022, at least 60 million individuals are estimated to develop post-acute sequelae of SARS-CoV-2 (PASC) after infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). While elevated levels of SARS-CoV-2-specific T cells have been observed in non-specific PASC, little is known about their impact on pulmonary function which is compromised in the majority of these individuals. This study compares frequencies of SARS-CoV-2-specific T cells and inflammatory markers with lung function in participants with pulmonary PASC and resolved COVID-19 (RC).

Compared to RC, participants with respiratory PASC had between 6- and 105-fold higher frequencies of IFN-γ- and TNF-α-producing SARS-CoV-2-specific CD4+ and CD8+ T cells in peripheral blood, and elevated levels of plasma CRP and IL-6. Importantly, in PASC participants the frequency of TNF-α-producing SARS-CoV-2-specific CD4+ and CD8+ T cells, which exhibited the highest levels of Ki67 indicating they were activity dividing, correlated positively with plasma IL-6 and negatively with measures of lung function, including forced expiratory volume in one second (FEV1), while increased frequencies of IFN-γ-producing SARS-CoV-2-specific T cells associated with prolonged dyspnea.

Statistical analyses stratified by age, number of comorbidities and hospitalization status demonstrated that none of these factors affect differences in the frequency of SARS-CoV-2 T cells and plasma IL-6 levels measured between PASC and RC cohorts. Taken together, these findings demonstrate elevated frequencies of SARS-CoV-2-specific T cells in individuals with pulmonary PASC are associated with increased systemic inflammation and decreased lung function, suggesting that SARS-CoV-2-specific T cells contribute to lingering pulmonary symptoms. These findings also provide mechanistic insight on the pathophysiology of PASC that can inform development of potential treatments to reduce symptom burden.

Source: Katherine M. Littlefield,Renée O. Watson,Jennifer M. Schneider,Charles P. Neff,Eiko Yamada,Min Zhang,Thomas B. Campbell,Michael T. Falta,Sarah E. Jolley,Andrew P. Fontenot,Brent E. Palmer. SARS-CoV-2-specific T cells associate with inflammation and reduced lung function in pulmonary post-acute sequalae of SARS-CoV-2. PLOS Pathogens. Published: May 26, 2022 https://doi.org/10.1371/journal.ppat.1010359  (Full text)

Cytokine network analysis in a community-based pediatric sample of patients with myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

Objectives: Studies have demonstrated immune dysfunction in adolescents with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS); however, evidence is varied. The current study used network analysis to examine relationships between cytokines among a sample of pediatric participants with ME/CFS.

Methods: 10,119 youth aged 5-17 in the Chicagoland area were screened for ME/CFS; 111 subjects and controls were brought in for a physician examination and completed a blood draw. Youth were classified as controls (Cs, N = 43), ME/CFS (N = 23) or severe (S-ME/CFS, N = 45). Patterns of plasma cytokine networks were analyzed.

Results: All participant groups displayed a primary network of interconnected cytokines. In the ME/CFS group, inflammatory cytokines IL-12p70, IL-17A, and IFN-γ were connected and included in the primary membership, suggesting activation of inflammatory mechanisms. The S-ME/CFS group demonstrated a strong relationship between IL-17A and IL-23, a connection associated with chronic inflammation. The relationships of IL-6 and IL-8 in ME/CFS and S-ME/CFS participants also differed from Cs. Together, these results indicate pro-inflammatory responses in our illness populations.

Discussion: Our data imply biological differences between our three participant groups, with ME/CFS and S-ME/CFS participants demonstrating an inflammatory profile. Examining co-expression of cytokines may aid in the identification of a biomarker for pediatric ME/CFS.

Source: Jason LA, Gaglio CL, Furst J, Islam M, Sorenson M, Conroy KE, Katz BZ. Cytokine network analysis in a community-based pediatric sample of patients with myalgic encephalomyelitis/chronic fatigue syndrome. Chronic Illn. 2022 May 16:17423953221101606. doi: 10.1177/17423953221101606. Epub ahead of print. PMID: 35570777.  https://pubmed.ncbi.nlm.nih.gov/35570777/

Analysis of post COVID-19 condition and its overlap with myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

Background: The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) disease (COVID-19) triggers the development of numerous pathologies and infection-linked complications and exacerbates existing pathologies in nearly all body systems. Aside from the primarily targeted respiratory organs, adverse SARS-CoV-2 effects were observed in nervous, cardiovascular, gastrointestinal/metabolic, immune, and other systems in COVID-19 survivors. Long-term effects of this viral infection have been recently observed and represent distressing sequelae recognised by the World Health Organisation (WHO) as a distinct clinical entity defined as post-COVID-19 condition. Considering the pandemic is still ongoing, more time is required to confirm post COVID-19 condition diagnosis in the COVID-19 infected cohorts, although many reported post COVID-19 symptoms overlap with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

Aims of Review: In this study, COVID-19 clinical presentation and associated post-infection sequelae (post-COVID-19 condition) were reviewed and compared with ME/CFS symptomatology.

Key Scientific Concepts of Review: The onset, progression, and symptom profile of post COVID-19 condition patients have considerable overlap with ME/CFS. Considering the large scope and range of pro-inflammatory effects of this virus, it is reasonable to expect development of post COVID-19 clinical complications in a proportion of the affected population. There are reports of a later debilitating syndrome onset three months post COVID-19 infection (often described as long-COVID-19), marked by the presence of fatigue, headache, cognitive dysfunction, post-exertional malaise, orthostatic intolerance, and dyspnoea. Acute inflammation, oxidative stress, and increased levels of interleukin-6 (IL-6) and tumor necrosis factor α (TNFα), have been reported in SARS-CoV-2 infected patients. Longitudinal monitoring of post COVID-19 patients is warranted to understand the long-term effects of SARS-CoV-2 infection and the pathomechanism of post COVID-19 condition.

Source: Sukocheva OA, Maksoud R, Beeraka NM, Madhunapantula SV, Sinelnikov M, Nikolenko VN, …. and Marshall-Gradisnik S. Analysis of post COVID-19 condition and its overlap with myalgic encephalomyelitis/chronic fatigue syndrome.  Journal of Advanced Research, Available online 26 November 2021. https://www.sciencedirect.com/science/article/pii/S2090123221002320  (Full text)