From Viral Infection to Autoimmune Reaction: Exploring the Link between Human Herpesvirus 6 and Autoimmune Diseases

Abstract:

The complexity of autoimmunity initiation has been the subject of many studies. Both genetic and environmental factors are essential in autoimmunity development. Among others, environmental factors include infectious agents. HHV-6 is a ubiquitous human pathogen with a high global prevalence. It has several properties suggestive of its contribution to autoimmunity development.
HHV-6 has a broad cell tropism, the ability to establish latency with subsequent reactivation and persistence, and a range of immunomodulation capabilities. Studies have implicated HHV-6 in a plethora of autoimmune diseases—endocrine, neurological, connective tissue, and others—with some studies even proposing possible autoimmunity induction mechanisms. HHV-6 can be frequently found in autoimmunity-affected tissues and lesions; it has been found to infect autoimmune-pathology-relevant cells and influence immune responses and signaling.
This review highlights some of the most well-known autoimmune conditions to which HHV-6 has been linked, like multiple sclerosis and autoimmune thyroiditis, and summarizes the data on HHV-6 involvement in autoimmunity development.
Source: Sokolovska L, Cistjakovs M, Matroze A, Murovska M, Sultanova A. From Viral Infection to Autoimmune Reaction: Exploring the Link between Human Herpesvirus 6 and Autoimmune Diseases. Microorganisms. 2024; 12(2):362. https://doi.org/10.3390/microorganisms12020362 https://www.mdpi.com/2076-2607/12/2/362 (Full text)

Brain-targeted autoimmunity is strongly associated with Long COVID and its chronic fatigue syndrome as well as its affective symptoms

Abstract:

Background Autoimmune responses contribute to the pathophysiology of Long COVID, affective symptoms and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

Objectives To examine whether Long COVID, and its accompanying affective symptoms and CFS are associated with immunoglobulin (Ig)A/IgM/IgG directed at neuronal proteins including myelin basic protein (MBP), myelin oligodendrocyte glycoprotein (MOG), synapsin, α+β-tubulin, neurofilament protein (NFP), cerebellar protein-2 (CP2), and the blood-brain-barrier-brain-damage (BBD) proteins claudin-5 and S100B.

Methods IgA/IgM/IgG to the above neuronal proteins, human herpes virus-6 (HHV-6) and Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) were measured in 90 Long COVID patients and 90 healthy controls, while C-reactive protein (CRP), and advanced oxidation protein products (AOPP) in association with affective and CFS ratings were additionally assessed in a subgroup thereof.

Results Long COVID is associated with significant increases in IgG directed at tubulin (IgG-tubulin), MBP, MOG and synapsin; IgM-MBP, MOG, CP2, synapsin and BBD; and IgA-CP2 and synapsin. IgM-SARS-CoV-2 and IgM-HHV-6 antibody titers were significantly correlated with IgA/IgG/IgM-tubulin and -CP2, IgG/IgM-BBD, IgM-MOG, IgA/IgM-NFP, and IgG/IgM-synapsin. Binary logistic regression analysis shows that IgM-MBP and IgG-MBP are the best predictors of Long COVID. Multiple regression analysis shows that IgG-MOG, CRP and AOPP explain together 41.7% of the variance in the severity of CFS. Neural network analysis shows that IgM-synapsin, IgA-MBP, IgG-MOG, IgA-synapsin, IgA-CP2, IgG-MBP and CRP are the most important predictors of affective symptoms due to Long COVID with a predictive accuracy of r=0.801.

Conclusion Brain-targeted autoimmunity contributes significantly to the pathogenesis of Long COVID and the severity of its physio-affective phenome.

Source: Abbas F. Almulla, Michael Maes, Bo Zhou, Hussein K. Al-Hakeim, Aristo Vojdani. Brain-targeted autoimmunity is strongly associated with Long COVID and its chronic fatigue syndrome as well as its affective symptoms. medRxiv [Preprint] https://www.medrxiv.org/content/10.1101/2023.10.04.23296554v1 (Full text available as PDF file)

Persistent SARS-CoV-2 Infection, EBV, HHV-6 and Other Factors May Contribute to Inflammation and Autoimmunity in Long COVID

Abstract:

A novel syndrome called long-haul COVID or long COVID is increasingly recognized in a significant percentage of individuals within a few months after infection with SARS-CoV-2. This disorder is characterized by a wide range of persisting, returning or even new but related symptoms that involve different tissues and organs, including respiratory, cardiac, vascular, gastrointestinal, musculo-skeletal, neurological, endocrine and systemic.
Some overlapping symptomatologies exist between long COVID and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Very much like with long ME/CFS, infections with herpes family viruses, immune dysregulation, and the persistence of inflammation have been reported as the most common pattern for the development of long COVID.
This review describes several factors and determinants of long COVID that have been proposed, elaborating mainly on viral persistence, reactivation of latent viruses such as Epstein–Barr virus and human herpesvirus 6 which are also associated with the pathology of ME/CFS, viral superantigen activation of the immune system, disturbance in the gut microbiome, and multiple tissue damage and autoimmunity.
Based on these factors, we propose diagnostic strategies such as the measurement of IgG and IgM antibodies against SARS-CoV-2, EBV, HHV-6, viral superantigens, gut microbiota, and biomarkers of autoimmunity to better understand and manage this multi-factorial disorder that continues to affect millions of people in the world.
Source: Vojdani A, Vojdani E, Saidara E, Maes M. Persistent SARS-CoV-2 Infection, EBV, HHV-6 and Other Factors May Contribute to Inflammation and Autoimmunity in Long COVID. Viruses. 2023; 15(2):400. https://doi.org/10.3390/v15020400 https://www.mdpi.com/1999-4915/15/2/400 (Full text)

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: The Human Herpesviruses Are Back!

Abstract:

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) or Systemic Exertion Intolerance Disease (SEID) is a chronic multisystem illness of unconfirmed etiology. There are currently no biomarkers and/or signatures available to assist in the diagnosis of the syndrome and while numerous mechanisms have been hypothesized to explain the pathology of ME/CFS, the triggers and/or drivers remain unknown.

Initial studies suggested a potential role of the human herpesviruses especially Epstein-Barr virus (EBV) in the disease process but inconsistent and conflicting data led to the erroneous suggestion that these viruses had no role in the syndrome. New studies using more advanced approaches have now demonstrated that specific proteins encoded by EBV could contribute to the immune and neurological abnormalities exhibited by a subgroup of patients with ME/CFS. Elucidating the role of these herpesvirus proteins in ME/CFS may lead to the identification of specific biomarkers and the development of novel therapeutics.

Source: Ariza ME. Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: The Human Herpesviruses Are Back! Biomolecules. 2021 Jan 29;11(2):185. doi: 10.3390/biom11020185. PMID: 33572802; PMCID: PMC7912523. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7912523/ (Full text)

Selective inhibition of miRNA processing by a herpesvirus-encoded miRNA

Abstract:

Herpesviruses have mastered host cell modulation and immune evasion to augment productive infection, life-long latency and reactivation1,2. A long appreciated, yet undefined relationship exists between the lytic-latent switch and viral non-coding RNAs3,4. Here we identify viral microRNA (miRNA)-mediated inhibition of host miRNA processing as a cellular mechanism that human herpesvirus 6A (HHV-6A) exploits to disrupt mitochondrial architecture, evade intrinsic host defences and drive the switch from latent to lytic virus infection.

We demonstrate that virus-encoded miR-aU14 selectively inhibits the processing of multiple miR-30 family members by direct interaction with the respective primary (pri)-miRNA hairpin loops. Subsequent loss of miR-30 and activation of the miR-30-p53-DRP1 axis triggers a profound disruption of mitochondrial architecture. This impairs induction of type I interferons and is necessary for both productive infection and virus reactivation.

Ectopic expression of miR-aU14 triggered virus reactivation from latency, identifying viral miR-aU14 as a readily druggable master regulator of the herpesvirus lytic-latent switch. Our results show that miRNA-mediated inhibition of miRNA processing represents a generalized cellular mechanism that can be exploited to selectively target individual members of miRNA families. We anticipate that targeting miR-aU14 will provide new therapeutic options for preventing herpesvirus reactivations in HHV-6-associated disorders.

Source: Hennig T, Prusty AB, Kaufer BB, Whisnant AW, Lodha M, Enders A, Thomas J, Kasimir F, Grothey A, Klein T, Herb S, Jürges C, Sauer M, Fischer U, Rudel T, Meister G, Erhard F, Dölken L, Prusty BK. Selective inhibition of miRNA processing by a herpesvirus-encoded miRNA. Nature. 2022 May;605(7910):539-544. doi: 10.1038/s41586-022-04667-4. Epub 2022 May 4. PMID: 35508655.  https://pubmed.ncbi.nlm.nih.gov/35508655/

Biomarkers in the diagnostic algorithm of myalgic encephalomyelitis/chronic fatigue syndrome

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex disease that is mainly diagnosed based on its clinical symptoms. Biomarkers that could facilitate the diagnosis of ME/CFS are not yet available; therefore, reliable and clinically useful disease indicators are of high importance. The aim of this work was to analyze the association between ME/CFS clinical course severity, presence of HHV-6A/B infection markers, and plasma levels of autoantibodies against adrenergic and muscarinic acetylcholine receptors.

A total of 134 patients with ME/CFS and 33 healthy controls were analyzed for the presence of HHV-6A/B using PCRs, and antibodies against beta2-adrenergic receptors (β2AdR) and muscarinic acetylcholine receptors (M3 AChR and M4 AChR) using ELISAs. HHV-6A/B U3 genomic sequence in whole-blood DNA was detected in 19/31 patients with severe ME/CFS, in 18/73 moderate ME/CFS cases, and in 7/30 mild ME/CFS cases. Severity-related differences were found among those with a virus load of more than 1,000 copies/106 PBMCs.

Although no disease severity-related differences in anti-β2AdR levels were observed in ME/CFS patients, the median concentration of these antibodies in plasma samples of ME/CFS patients was 1.4 ng/ml, while in healthy controls, it was 0.81 ng/ml, with a statistically significant increased level in those with ME/CFS (p = 0.0103). A significant difference of antibodies against M4 AChR median concentration was found between ME/CFS patients (8.15 ng/ml) and healthy controls (6.45 ng/ml) (p = 0.0250). The levels of anti-M4 plotted against disease severity did not show any difference; however, increased viral load correlates with the increase in anti-M4 level.

ME/CFS patients with high HHV-6 load have a more severe course of the disease, thus confirming that the severity of the disease depends on the viral load—the course of the disease is more severe with a higher viral load. An increase in anti-M4 AchR and anti-β2AdR levels is detected in all ME/CFS patient groups in comparison to the control group not depending on ME/CFS clinical course severity. However, the increase in HHV-6 load correlates with the increase in anti-M4 level, and the increase in anti-M4 level, in turn, is associated with the increase in anti-β2AdR level. Elevated levels of antibodies against β2AdR and M4 receptors in ME/CFS patients support their usage as clinical biomarkers in the diagnostic algorithm of ME/CFS.

Source: Gravelsina S, Vilmane A, Svirskis S, Rasa-Dzelzkaleja S, Nora-Krukle Z, Vecvagare K, Krumina A, Leineman I, Shoenfeld Y and Murovska M (2022) Biomarkers in the diagnostic algorithm of myalgic encephalomyelitis/chronic fatigue syndrome. Front. Immunol. 13:928945. doi: 10.3389/fimmu.2022.928945 https://www.frontiersin.org/articles/10.3389/fimmu.2022.928945/full (Full text)

Herpesvirus and neurological manifestations in patients with severe coronavirus disease

Abstract:

Background: Certain clinical manifestations of coronavirus disease (COVID-19) mimic those associated with human herpesvirus (HHV) infection. In this study, we estimated the prevalence of herpesvirus in patients with COVID-19 and determined if coinfection is associated with poorer outcomes and neurological symptoms.

Methods: We analyzed samples of 53 patients diagnosed with COVID-19. The samples were evaluated for the presence of alphaherpesviruses, betaherpesviruses, and gammaherpesviruses, and the viral loads were quantified using quantitative polymerase chain reaction (qPCR) method.

Results: Among the patients, in 79.2% had detection at least one type of herpesvirus. HHV-6 (47.2%), cytomegalovirus (43.3%), and HHV-7 (39.6%) showed the highest detection rates. Patients with a high severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) load were more likely to show herpes simplex virus 1 detection (p = 0.037). Among patients coinfected with SARS-CoV-2 and HHVs, 26.4% showed central nervous system-associated neurological symptoms and herpetic manifestations. A statistically significant association was observed between neurological changes and HHV-6 detection (p = 0.034).

Conclusions: The findings showed a high prevalence of herpesvirus in patients with COVID-19. Furthermore, even though SARS-CoV-2 and HHV coinfection was not associated with poorer outcomes, the findings demonstrated the association between neurological symptoms and HHV-6 detection.

Source: Carneiro VCS, Alves-Leon SV, Sarmento DJS, Coelho WLDCNP, Moreira ODC, Salvio AL, Ramos CHF, Ramos Filho CHF, Marques CAB, da Costa Gonçalves JP, Leon LAA, de Paula VS. Herpesvirus and neurological manifestations in patients with severe coronavirus disease. Virol J. 2022 Jun 8;19(1):101. doi: 10.1186/s12985-022-01828-9. PMID: 35676707; PMCID: PMC9174631. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9174631/  (Full text)

Detection of herpes viruses in patients with myalgic encephalomyelitis /chronic fatigue syndrome in Belarus

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a multifactorial chronic disease. The etiology and pathogenesis of ME/CFS are unknown. There are many theories for the occurrence of this disease. but the most convincing is the infectious or viral theory of the emergence of CFS.

The aim of this study is to detect of herpes viruses 6, 7 types and Epstein-Barr  to examine the prevalence HHV-6, HHV-7 and EBV infections in Belarus CFS patients.

We examined 30 patients with CFS in whom fatigue during  more than 2 years (7), more than 1 year (11) and more than 6 months (12). The diagnosis was made on clinical grounds using the Fukuda criteria.

The presence of markers the active forms  infection HHV-6 and HHV-7 in CFS patients with a long period of fatigue  were detected in 16.6% and 26.6% respectively. IgM  antibodies to HHV-6 and EBV. positive, in 16.6% and 6.7% respectively in patients with long-term illness. Detection of IgG antibodies indicates a quiet carrier state, latent phase.

Source: ORLOVA, Svetlana et al. Detection of herpes viruses in patients with myalgic encephalomyelitis /chronic fatigue syndrome in Belarus. Polish Journal of Applied Sciences, [S.l.], v. 6, n. 2, p. 50-53, dec. 2021. ISSN 2451-1544. Available at: <https://pjas.pwsip.edu.pl/index.php/pjas/article/view/176>. Date accessed: 10 jan. 2022. doi: https://doi.org/10.34668/PJAS.2020.6.2.08. (Full text)

Salivary DNA Loads for Human Herpesviruses 6 and 7 Are Correlated With Disease Phenotype in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Abstract:

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a complex chronic condition affecting multiple body systems, with unknown cause, unclear pathogenesis mechanisms, and fluctuating symptoms which may lead to severe debilitation. It is frequently reported to have been triggered by an infection, but there are no clear differences in exposure to, or seroprevalence of, any particular viruses between people with ME/CFS and healthy individuals. However, herpes viruses have been repeatedly hypothesized to underlie the chronic relapsing/remitting form of MS/CFS due to their persistence in a latent form with periodic reactivation. It is possible that ME/CFS is associated with herpes virus reactivation, which has not been detectable previously due to insufficiently sensitive testing methods.

Saliva samples were collected from 30 people living with ME/CFS at monthly intervals for 6 months and at times when they experienced symptom exacerbation, as well as from 14 healthy control individuals. The viral DNA load of the nine humanherpes viruses was determined by digital droplet PCR. Symptoms were assessed by questionnaire at each time point. Human herpesvirus (HHV) 6B, HHV-7, herpes simplex virus 1 and Epstein-Barr virus were detectable within the saliva samples, with higher HHV-6B and HHV-7 viral loads detected in people with ME/CFS than in healthy controls.

Participants with ME/CFS could be broadly separated into two groups: one group displayed fluctuating patterns of herpesviruses detectable across the 6 months while the second group displayed more stable viral presentation. In the first group, there was positive correlation between HHV-6B and HHV-7 viral load and severity of symptom scores, including pain, neurocognition, and autonomic dysfunction.

The results indicate that fluctuating viral DNA load correlates with ME/CFS symptoms: this is in accordance with the hypothesis that pathogenesis is related to herpesvirus reactivation state, and this should be formally tested. Herpesvirus reactivation might be a cause or consequence of dysregulated immune function seen in ME/CFS. The sampling strategy and molecular tools developed here permit such large-scale epidemiological investigations.

Source: Lee JS, Lacerda EM, Nacul L, Kingdon CC, Norris J, O’Boyle S, Roberts CH, Palla L, Riley EM, Cliff JM. Salivary DNA Loads for Human Herpesviruses 6 and 7 Are Correlated With Disease Phenotype in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Front Med (Lausanne). 2021 Aug 6;8:656692. doi: 10.3389/fmed.2021.656692. PMID: 34422848; PMCID: PMC8378328. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8378328/  (Full text)

Human herpesvirus 6 infection and risk of Chronic fatigue syndrome: a systematic review and meta-analysis

Abstract:

Introduction: Chronic fatigue syndrome (CFS) is a neurological disease that is accompanied by excessive fatigue or tiredness. There are several reports confirming the association between human herpesvirus 6 (HHV-6) infection and CFS illness. This systematic review and meta-analysis was performed to integrate the information of published studies with regard to this association until May 2021.

Methods: The literature search was based on keywords including “chronic fatigue syndrome and HHV 6,” “chronic fatigue syndrome and HHV-6,” “chronic fatigue syndrome and HHV6,” “chronic fatigue syndrome and Herpes virus 6,” and “chronic fatigue syndrome and Herpesvirus6” in MEDLINE (PubMed), Web of Science, and EMBASE.

Results: The literature search identified 17 studies to be included in the systematic review and 11 studies in meta-analysis. The symmetry funnel plot and Egger’s test (p value = 0.2) identified no publication bias among studies. Moreover, the low level of I2 revealed homogeneity across studies.

Discussion: In conclusion, the association between the HHV-6 infection and CFS incidence was substantiated. However, the results of this study also suggest that further comprehensive studies are needed to solidify the association between HHV-6 and CFS. Future studies should consider additional factors that may have affected the significance of such a correlation.

Source: Sayed-Hamidreza Mozhgani, Farid Rajabi, Mohsen Qurbani, Yousef Erfani, Somayeh Yaslianifard, Azam Moosavi, Kiomars Pourrostami, Ali Baradaran Bagheri, Alireza Soleimani, Farida Behzadian, Mahshid Safavi, Farhad Rezaei. Human herpesvirus 6 infection and risk of Chronic fatigue syndrome: a systematic review and meta-analysis. Intervirology (IF1.763), Pub Date : 2021-06-23, DOI: 10.1159/000517930 https://www.karger.com/Article/Abstract/517930 (Full text as PDF file)