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 FADE syndrome: the final common pathway of chronic inflammation in neurological disease

Abstract:

Importance: While the understanding of inflammation in the pathogenesis of many neurological diseases is now accepted, this special commentary addresses the need to study chronic inflammation in the propagation of cognitive Fog, Asthenia, and Depression Related to Inflammation which we name Brain FADE syndrome. Patients with Brain FADE syndrome fall in the void between neurology and psychiatry because the depression, fatigue, and fog seen in these patients are not idiopathic, but instead due to organic, inflammation involved in neurological disease initiation.

Observations: A review of randomized clinical trials in stroke, multiple sclerosis, Parkinson’s disease, COVID, traumatic brain injury, and Alzheimer’s disease reveal a paucity of studies with any component of Brain FADE syndrome as a primary endpoint. Furthermore, despite the relatively well-accepted notion that inflammation is a critical driving factor in these disease pathologies, none have connected chronic inflammation to depression, fatigue, or fog despite over half of the patients suffering from them.

Conclusions and relevance: Brain FADE Syndrome is important and prevalent in the neurological diseases we examined. Classical “psychiatric medications” are insufficient to address Brain FADE Syndrome and a novel approach that utilizes sequential targeting of innate and adaptive immune responses should be studied.

Source: Khalid A. Hanafy, Tudor G. Jovin. Brain FADE syndrome: the final common pathway of chronic inflammation in neurological disease. Front. Immunol., 17 January 2024, Sec. Inflammation, Volume 15 – 2024 | https://doi.org/10.3389/fimmu.2024.1332776 https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2024.1332776/full (Full text)

Frequency and characteristics of chronic fatigue syndrome in multiple sclerosis patients at a university hospital in Eastern Saudi Arabia

Abstract:

BACKGROUND: Multiple sclerosis (MS) is a chronic, inflammatory demyelinating disease that affects various parts of the central nervous system. Fatigue, a common symptom, transient, prolonged, or chronic experienced by individuals with MS, can significantly impact daily functioning. It can be associated with underlying pathological processes or can have an idiopathic cause, such as chronic fatigue syndrome (CFS). The study aimed to assess the presence and etiology of fatigue in MS patients and its relationship with CFS.

MATERIALS AND METHODS: This cross-sectional study was conducted in the Eastern Province of Saudi Arabia. Data were collected using a questionnaire from a sample of 225 MS patients receiving care at our university hospital. The questionnaire included the Centers for Disease Control and Prevention (CDC) criteria for diagnosing CFS and the Expanded Disability Status Scale to evaluate fatigue in MS patients.

RESULTS: Of the total of 225 MS patients who participated in this study, 87.1% were diagnosed with relapsing-remitting MS, 6.7% with primary progressive MS, 3.6% with clinically isolated syndrome, and 2.7% with secondary progressive MS. About 53% had experienced fatigue that persisted for over 6 months. Analysis of CFS diagnosis revealed that 7.3% of patients met both CDC criteria and self-reported answers while 17.5% reported having CFS despite not meeting the CDC criteria. These findings highlight a significant lack of agreement between patient-reported diagnoses and established criteria, indicating poor agreement (P = 0.028).

CONCLUSION: The study found an association between CFS and MS, and a significant impact on daily functioning. The study revealed lack of agreement between patient-reported diagnoses and established criteria for CFS. This emphasizes the need for a standardized approach to diagnosis and evaluation of fatigue in MS patients.

Source: AlAmri, Abdullah S.; AlShamrani, Foziah J.; AlMohish, Noor M.; Zafar, Azra S.; Alnaaim, Saud A.1; Alazman, Hatem A.; Al-Ghanimi, Ibrahim A.2; AlNahdi, Abdullah A.; AlDawsari, Fahad A.; AlMatrafi, Shahad B.3; Alzahrani, Ghaida R.3; Alnamlah, Muna S.; Alkhalifa, Rawan A.. Frequency and characteristics of chronic fatigue syndrome in multiple sclerosis patients at a university hospital in Eastern Saudi Arabia. Journal of Family and Community Medicine 31(1):p 63-70, Jan–Mar 2024. | DOI: 10.4103/jfcm.jfcm_73_23 https://journals.lww.com/jfcm/fulltext/2024/31010/frequency_and_characteristics_of_chronic_fatigue.9.aspx (Full text)

Catalytic Antibodies May Contribute to Demyelination in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Abstract:

Here we report preliminary data demonstrating that some patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) may have catalytic autoantibodies that cause the breakdown of myelin basic protein (MBP). We propose that these MBP-degradative antibodies are important to the pathophysiology of ME/CFS, particularly in the occurrence of white matter disease/demyelination. This is supported by magnetic resonance imagining studies that show these findings in patients with ME/CFS and could explain symptoms of nerve pain and muscle weakness.

In this work, we performed a series of experiments on patient plasma samples where we isolated and characterized substrate-specific antibodies that digest MBP. We also tested glatiramer acetate (copaxone), an FDA approved immunomodulator to treat multiple sclerosis, and found that it inhibits ME/CFS antibody digestion of MBP. Furthermore, we found that aprotinin, which is a specific serine protease inhibitor, specifically prevents breakdown of MBP while the other classes of protease inhibitors had no effect. This coincides with the published literature describing catalytic antibodies as having serine protease-like activity. Postpandemic research has also provided several reports of demyelination in COVID-19.

Because COVID-19 has been described as a trigger for ME/CFS, demyelination could play a bigger role in patient symptoms for those recently diagnosed with ME/CFS. Therefore, by studying proteolytic antibodies in ME/CFS, their target substrates, and inhibitors, a new mechanism of action could lead to better treatment and a possible cure for the disease.

Source: Jensen MA, Dafoe ML, Wilhelmy J, Cervantes L, Okumu AN, Kipp L, Nemat-Gorgani M, Davis RW. Catalytic Antibodies May Contribute to Demyelination in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Biochemistry. 2023 Nov 27. doi: 10.1021/acs.biochem.3c00433. Epub ahead of print. PMID: 38011893. https://pubs.acs.org/doi/10.1021/acs.biochem.3c00433 (Full text)

Evidence of a Novel Mitochondrial Signature in Systemic Sclerosis Patients with Chronic Fatigue Syndrome

Abstract:

Symptoms of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) are common in rheumatic diseases, but no studies report the frequency of these in early systemic sclerosis. There are no known biomarkers that can distinguish between patients with ME/CFS, although mitochondrial abnormalities are often demonstrated.

We sought to assess the prevalence of ME/CFS in limited cutaneous SSc (lcSSc) patients early in their disease (<5 years from the onset of non-Raynaud’s symptoms) and to determine if alterations in mitochondrial electron transport chain (ETC) transcripts and mitochondrial DNA (mtDNA) integrity could be used to distinguish between fatigued and non-fatigued patients.

All SSc patients met ACR/EULAR classification criteria. ME/CFS-related symptoms were assessed through validated questionnaires, and the expression of ETC transcripts and mtDNA integrity were quantified via qPCR.

SSc patients with ME/CFS could be distinguished from non-fatigued patients through ETC gene analysis; specifically, reduced expression of ND4 and CyB and increased expression of Cox7C. ND4 and CyB expression correlated with indicators of disease severity.

Further prospective and functional studies are needed to determine if this altered signature can be further utilized to better identify ME/CFS in SSc patients, and whether ME/CFS in early SSc disease could predict more severe disease outcomes.

Source: van Eeden C, Redmond D, Mohazab N, Larché MJ, Mason AL, Cohen Tervaert JW, Osman MS. Evidence of a Novel Mitochondrial Signature in Systemic Sclerosis Patients with Chronic Fatigue Syndrome. International Journal of Molecular Sciences. 2023; 24(15):12057. https://doi.org/10.3390/ijms241512057 https://www.mdpi.com/1422-0067/24/15/12057 (Full text)

Association analysis between symptomology and herpesvirus IgG antibody concentrations in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and multiple sclerosis

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and multiple sclerosis (MS) are two complex and multifactorial diseases whose patients experience persistent fatigue, cognitive impairment, among other shared symptoms. The onset of these diseases has also been linked to acute herpesvirus infections or their reactivations.

In this work, we re-analyzed a previously-described dataset related to IgG antibody responses to 6 herpesviruses (CMV – cytomegalovirus; EBV – Epstein-Barr virus; HHV6 – human herpesvirus-6; HSV1 and HSV2 – herpes simplex virus-1 and -2; VZV – varicella-zoster virus) from the United Kingdom ME/CFS biobank. The primary goal was to report the underlying symptomology and its association with herpesvirus IgG antibodies using data from 4 disease-trigger-based subgroups of ME/CFS patients (n = 222) and patients with MS (n = 46). A secondary objective was to assess whether serological data could distinguish ME/CFS and its subgroup from MS using a SuperLearner (SL) algorithm.

There was evidence for a significant negative association between temporary eye insight disturbance and CMV antibody concentrations and for a significant positive association between bladder problems and EBV antibody concentrations in the MS group.

In the ME/CFS or its subgroups, the most significant antibody-symptom association was obtained for increasing HSV1 antibody concentration and brain fog, a finding in line with a negative impact of HSV1 exposure on cognitive outcomes in both healthy and disease conditions. There was also evidence for a higher number of significant antibody-symptom associations in the MS group than in the ME/CFS group.

When we combined all the serological data in an SL algorithm, we could distinguish three ME/CFS subgroups (unknown disease trigger, non-infection trigger, and an infection disease trigger confirmed in the lab at the time of the event) from the MS group. However, we could not find the same for the remaining ME/CFS group (related to an unconfirmed infection disease).

In conclusion, IgG antibody data explains more the symptomology of MS patients than the one of ME/CFS patients. Given the fluctuating nature of symptoms in ME/CFS patients, the clinical implication of these findings remains to be determined with a longitudinal study. This study is likely to ascertain the robustness of the associations during natural disease course.

Source: Tiago Dias Domingues, João Malato, Anna D. Grabowska, Ji-Sook Lee, Jose Ameijeiras-Alonso, Przemyslaw Biecek, Luís Graça, Helena Mouriño, Carmen Scheibenbogen, Francisco Westermeier, Luis Nacul, Jacqueline M. Cliff, Eliana Lacerda, Nuno Sepúlveda,
Association analysis between symptomology and herpesvirus IgG antibody concentrations in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and multiple sclerosis. Heliyon, https://doi.org/10.1016/j.heliyon.2023.e18250 https://www.sciencedirect.com/science/article/pii/S2405844023054580 (Full text)

Health outcomes of sensory hypersensitivities in myalgic encephalomyelitis/chronic fatigue syndrome and multiple sclerosis

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a poorly understood chronic illness with many case definitions that disagree on key symptoms, including hypersensitivities to noise and lights. The aim of the current study was to understand the prevalence rates and characteristics of these symptoms amongst people with ME/CFS and to compare them to people with another chronic illness, multiple sclerosis (MS).

International datasets consisting of 2,240 people with either ME/CFS or MS have completed the DePaul Symptom Questionnaire (DSQ) and the Short Form Health Survey Questionnaire (SF-36). Hypersensitivities to noise and lights were indicated from items on the DSQ, and participants were analyzed against DSQ and SF-36 subscales through a multivariate analysis of covariance.

There were significantly higher percentages of people with hypersensitivities in the ME/CFS sample compared to the MS sample. Regardless of illness, participants that exhibited both hypersensitivities reported greater symptomology than those without hypersensitivities. Healthcare providers and researchers should consider these symptoms when developing treatment plans and evaluating ME/CFS case diagnostic criteria.

Source: Maeda KI, Islam MF, Conroy KE, Jason L. Health outcomes of sensory hypersensitivities in myalgic encephalomyelitis/chronic fatigue syndrome and multiple sclerosis. Psychol Health Med. 2023 Mar 28:1-12. doi: 10.1080/13548506.2023.2195670. Epub ahead of print. PMID: 36977713. https://pubmed.ncbi.nlm.nih.gov/36977713/

Epstein-Barr virus may be leading cause of multiple sclerosis

Press Release:

January 13, 2022: Multiple sclerosis (MS), a progressive disease that affects 2.8 million people worldwide and for which there is no definitive cure, is likely caused by infection with the Epstein-Barr virus (EBV), according to a study led by Harvard T.H. Chan School of Public Health researchers.

Their findings will be published online in Science on January 13, 2022.

“The hypothesis that EBV causes MS has been investigated by our group and others for several years, but this is the first study providing compelling evidence of causality,” said Alberto Ascherio, professor of epidemiology and nutrition at Harvard Chan School and senior author of the study. “This is a big step because it suggests that most MS cases could be prevented by stopping EBV infection, and that targeting EBV could lead to the discovery of a cure for MS.”

MS is a chronic inflammatory disease of the central nervous system that attacks the myelin sheaths protecting neurons in the brain and spinal cord. Its cause is not known, yet one of the top suspects is EBV, a herpes virus that can cause infectious mononucleosis and establishes a latent, lifelong infection of the host. Establishing a causal relationship between the virus and the disease has been difficult because EBV infects approximately 95% of adults, MS is a relatively rare disease, and the onset of MS symptoms begins about ten years after EBV infection. To determine the connection between EBV and MS, the researchers conducted a study among more than 10 million young adults on active duty in the U.S. military and identified 955 who were diagnosed with MS during their period of service.

The team analyzed serum samples taken biennially by the military and determined the soldiers’ EBV status at time of first sample and the relationship between EBV infection and MS onset during the period of active duty. In this cohort, the risk of MS increased 32-fold after infection with EBV but was unchanged after infection with other viruses. Serum levels of neurofilament light chain, a biomarker of the nerve degeneration typical in MS, increased only after EBV infection. The findings cannot be explained by any known risk factor for MS and suggest EBV as the leading cause of MS.

Ascherio says that the delay between EBV infection and the onset of MS may be partially due the disease’s symptoms being undetected during the earliest stages and partially due to the evolving relationship between EBV and the host’s immune system, which is repeatedly stimulated whenever latent virus reactivates.

“Currently there is no way to effectively prevent or treat EBV infection, but an EBV vaccine or targeting the virus with EBV-specific antiviral drugs could ultimately prevent or cure MS,” said Ascherio.

Other Harvard Chan School researchers who contributed to this study include Kjetil Bjornevik, Marianna Cortese, Michael Mina, and Kassandra Munger.

Funding for this study came the National Institute of Neurological Disorders and Stroke, National Institutes of Health (NS046635, NS042194, and NS103891), the National Multiple Sclerosis Society (PP-1912-35234), the German Research Foundation (CO 2129/ 1-1), the National Institutes of Health (DP5- OD028145), and the Howard Hughes Medical Institute.

Source: Materials provided by Harvard T.H. Chan School of Public Health.

Increased CD8+ T cell response to Epstein-Barr virus lytic antigens in the active phase of multiple sclerosis

Abstract:

It has long been known that multiple sclerosis (MS) is associated with an increased Epstein-Barr virus (EBV) seroprevalence and high immune reactivity to EBV and that infectious mononucleosis increases MS risk. This evidence led to postulate that EBV infection plays a role in MS etiopathogenesis, although the mechanisms are debated. This study was designed to assess the prevalence and magnitude of CD8+ T-cell responses to EBV latent (EBNA-3A, LMP-2A) and lytic (BZLF-1, BMLF-1) antigens in relapsing-remitting MS patients (n = 113) and healthy donors (HD) (n = 43) and to investigate whether the EBV-specific CD8+ T cell response correlates with disease activity, as defined by clinical evaluation and gadolinium-enhanced magnetic resonance imaging.

Using HLA class I pentamers, lytic antigen-specific CD8+ T cell responses were detected in fewer untreated inactive MS patients than in active MS patients and HD while the frequency of CD8+ T cells specific for EBV lytic and latent antigens was higher in active and inactive MS patients, respectively. In contrast, the CD8+ T cell response to cytomegalovirus did not differ between HD and MS patients, irrespective of the disease phase. Marked differences in the prevalence of EBV-specific CD8+ T cell responses were observed in patients treated with interferon-β and natalizumab, two licensed drugs for relapsing-remitting MS.

Longitudinal studies revealed expansion of CD8+ T cells specific for EBV lytic antigens during active disease in untreated MS patients but not in relapse-free, natalizumab-treated patients. Analysis of post-mortem MS brain samples showed expression of the EBV lytic protein BZLF-1 and interactions between cytotoxic CD8+ T cells and EBV lytically infected plasma cells in inflammatory white matter lesions and meninges. We therefore propose that inability to control EBV infection during inactive MS could set the stage for intracerebral viral reactivation and disease relapse.

Source: Angelini DF, Serafini B, Piras E, Severa M, Coccia EM, Rosicarelli B, Ruggieri S, Gasperini C, Buttari F, Centonze D, Mechelli R, Salvetti M, Borsellino G, Aloisi F, Battistini L. Increased CD8+ T cell response to Epstein-Barr virus lytic antigens in the active phase of multiple sclerosis. PLoS Pathog. 2013;9(4):e1003220. doi: 10.1371/journal.ppat.1003220. Epub 2013 Apr 11. PMID: 23592979; PMCID: PMC3623710. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3623710/ (Full text)

Recovery From COVID-19 in Multiple Sclerosis: A Prospective and Longitudinal Cohort Study of the United Kingdom Multiple Sclerosis Register

Abstract:

Background and objectives: To understand the course of recovery from coronavirus disease 2019 (COVID-19) among patients with multiple sclerosis (MS) and to determine its predictors, including patients’ pre-COVID-19 physical and mental health status.

Methods: This prospective and longitudinal cohort study recruited patients with MS who reported COVID-19 from March 17, 2020, to March 19, 2021, as part of the United Kingdom MS Register (UKMSR) COVID-19 study. Participants used online questionnaires to regularly update their COVID-19 symptoms, recovery status, and duration of symptoms for those who fully recovered. Questionnaires were date stamped for estimation of COVID-19 symptom duration for those who had not recovered at their last follow-up. The UKMSR holds demographic and up-to-date clinical data on participants as well as their web-based Expanded Disability Status Scale (web-EDSS) and Hospital Anxiety and Depression Scale (HADS) scores. The association between these factors and recovery from COVID-19 was assessed using multivariable Cox regression analysis.

Results: Of the 7,977 patients with MS who participated in the UKMSR COVID-19 study, 599 reported COVID-19 and prospectively updated their recovery status. Twenty-eight hospitalized participants were excluded. At least 165 participants (29.7%) had long-standing COVID-19 symptoms for ≥4 weeks and 69 (12.4%) for ≥12 weeks. Participants with pre-COVID-19 web-EDSS scores ≥7, participants with probable anxiety and/or depression (HADS scores ≥11) before COVID-19 onset, and women were less likely to report recovery from COVID-19.

Discussion: Patients with MS are affected by postacute sequelae of COVID-19. Preexisting severe neurologic impairment or mental health problems appear to increase this risk. These findings can have implications in tailoring their post-COVID-19 rehabilitation.

Source: Garjani A, Middleton RM, Nicholas R, Evangelou N. Recovery From COVID-19 in Multiple Sclerosis: A Prospective and Longitudinal Cohort Study of the United Kingdom Multiple Sclerosis Register. Neurol Neuroimmunol Neuroinflamm. 2021 Nov 30;9(1):e1118. doi: 10.1212/NXI.0000000000001118. PMID: 34848503; PMCID: PMC8631790. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8631790/ (Full text)