Category: Pathogenesis

Editorial: The Pathogenesis of Long-Term Neuropsychiatric COVID-19 and the Role of Microglia, Mitochondria, and Persistent Neuroinflammation: A Hypothesis

Abstract:

Persistent comorbidities occur in patients who initially recover from acute coronavirus disease 2019 (COVID-19) due to infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). ‘Long COVID’ involves the central nervous system (CNS), resulting in neuropsychiatric symptoms and signs, including cognitive impairment or ‘brain fog’ and chronic fatigue syndrome. There are similarities in these persistent complications between SARS-CoV-2 and the Ebola, Zika, and influenza A viruses. Normal CNS neuronal mitochondrial function requires high oxygen levels for oxidative phosphorylation and ATP production. Recent studies have shown that the SARS-CoV-2 virus can hijack mitochondrial function. Persistent changes in cognitive functioning have also been reported with other viral infections. SARS-CoV-2 infection may result in long-term effects on immune processes within the CNS by causing microglial dysfunction. This short opinion aims to discuss the hypothesis that the pathogenesis of long-term neuropsychiatric COVID-19 involves microglia, mitochondria, and persistent neuroinflammation.

Source: Stefano GB, Büttiker P, Weissenberger S, Martin A, Ptacek R, Kream RM. Editorial: The Pathogenesis of Long-Term Neuropsychiatric COVID-19 and the Role of Microglia, Mitochondria, and Persistent Neuroinflammation: A Hypothesis. Med Sci Monit. 2021 May 10;27:e933015. doi: 10.12659/MSM.933015. PMID: 34016942. https://pubmed.ncbi.nlm.nih.gov/34016942/

Case Study Suggests Young People Susceptible To Chronic Fatigue Syndrome After Covid-19

Press Release:

With more adolescents and young adults being treated for COVID-19, clinicians are concerned that these people also will start showing post-COVID — or “long haul” — symptoms from their bouts with the virus. A recent Johns Hopkins Medicine review of three case studies provides some of the first evidence that one serious post-COVID problem may be myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), the complex, multisystem disorder previously known as chronic fatigue syndrome.

The findings were published April 29 in the journal Frontiers in Medicine.

“In the three patients studied — all of whom had confirmed or highly probable COVID-19 infections early in the pandemic — we observed ME/CFS-like symptoms within the first two weeks of illness,” says Peter Rowe, M.D., director of the Chronic Fatigue Clinic at Johns Hopkins Children’s Center and professor of pediatrics at the Johns Hopkins University School of Medicine. “At six months following their illness, all three still met the criteria for being diagnosed with ME/CFS.”

In a recent report, the U.S. Centers for Disease Control and Prevention (CDC) noted that U.S. hospitals are seeing more adolescents and young adults admitted with COVID-19 as more contagious variants of SARS-CoV-2 — the virus that causes the disease — spread. The agency believes that the youthful case surge may be the result of those ages 10 to 24 being among the last prioritized to get the coronavirus vaccines, and the fact that many who are eligible have yet to receive their shots. Also, the CDC says, this group is more likely to be involved in high-risk behaviors such as playing close-contact sports and going out to bars.

The three patients evaluated in the recent study were a 19-year-old man and two women, ages 22 and 30, whose COVID-19 symptoms began between April and June 2020, and who were referred to the Chronic Fatigue Clinic between August and October of the same year. Symptoms of orthostatic intolerance — a group of clinical conditions that includes fatigue, lightheadedness and difficulty concentrating, and are linked with greater than 90% of the people with ME/CFS — were prominent in all three from the outset of their COVID-19 illness.

A six-month post-COVID symptom onset examination, including evaluations of movement, neurological function and continued orthostatic intolerance, was conducted on each of the patients to determine if ME/CFS could be diagnosed. All three easily met the criteria.

Interestingly, Rowe says, all three patients had relatively mild COVID-19 respiratory symptoms and none required hospitalization, yet it appears to have translated into the more serious secondary problem of ME/CFS for them all.

“This finding is consistent with previous studies in older patients with COVID-19 who showed persistent fatigue months after infection, regardless of the severity of the initial infection,” he explains. “This raises the question of how many ME/CFS cases before the COVID-19 pandemic might have been due to mild, subclinical or asymptomatic viral infections [such as Epstein-Barr virus or human herpesvirus 6], including cases in adolescents, young adults and older people.”

Rowe and his colleagues feel that further research is needed to define the biological mechanism by which ME/CFS arises from COVID-19, and then use that insight to develop treatment strategies that can return patients with post-COVID ME/CFS back to their previous quality of life.

Rowe is available for interviews.

https://www.hopkinsmedicine.org/news/newsroom/news-releases/covid-19-story-tip-case-study-suggests-young-people-may-be-susceptible-to-chronic-fatigue-following-covid-19

Media Contact: Michael E. Newman, mnewma25@jhmi.edu

Adolescent and Young Adult ME/CFS After Confirmed or Probable COVID-19

Abstract:

Introduction: Fatigue is a common acute symptom following SARS-CoV-2 infection (COVID-19). The presence of persistent fatigue and impaired daily physical and cognitive function has led to speculation that like SARS-CoV-1 infection, COVID-19 will be followed by myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

Methods and Results: We describe three adolescent and young adult patients who had confirmed or probable COVID-19 infections early on during the pandemic and were referred for evaluation to the Chronic Fatigue Clinic at the Johns Hopkins Children’s Center. All patients reported orthostatic intolerance symptoms within the first 2 weeks of illness, and 10-min passive standing tests were consistent with postural tachycardia syndrome. After 6 months of illness, all three patients met criteria for ME/CFS. Clinical features of interest included strong histories of allergies in all three patients, two of whom had elevations in plasma histamine. Each demonstrated limitations in symptom-free range of motion of the limbs and spine and two presented with pathological Hoffman reflexes. These comorbid features have been reported in adolescents and young adults with ME/CFS.

Conclusion: ME/CFS can be triggered by COVID-19 in adolescents and young adults. Further work is needed to determine the pathogenesis of ME/CFS after COVID-19 and optimal methods of treating these patients. Our preliminary study calls attention to several comorbid features that deserve further attention as potential targets for intervention. These include neuromuscular limitations that could be treated with manual forms of therapy, orthostatic intolerance and POTS for which there are multiple medications and non-pharmacologic therapies, treatable allergic and mast cell phenomena, and neurologic abnormalities that may require specific treatment. Larger studies will need to ascertain the prevalence of these abnormalities.

Source: Petracek LS, Suskauer SJ, Vickers RF, Patel NR, Violand RL, Swope RL, Rowe PC. Adolescent and Young Adult ME/CFS After Confirmed or Probable COVID-19. Front Med (Lausanne). 2021 Apr 29;8:668944. doi: 10.3389/fmed.2021.668944. PMID: 33996867; PMCID: PMC8116546. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8116546/ (Full text)

Prevalence and correlates of chronic fatigue syndrome and post-traumatic stress disorder after the outbreak of the COVID-19

Abstract:

As the SARS-COV-2 becomes a global pandemic, many researchers have a concern about the long COVID-19 complications. Chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) is a persistent, debilitating, and unexplained fatigue disorder. We investigated psychological morbidities such as CFS and post-traumatic stress disorder (PTSD) among survivors of COVID-19 over 6 months.

All COVID-19 survivors from the university-affiliated hospital of Tehran, Iran, were assessed 6 months after infection onset by a previously validated questionnaire based on the Fukuda guidelines for CFS/EM and DSM-5 Checklist for PTSD (The Post-traumatic Stress Disorder Checklist for DSM-5 or PCL-5) to determine the presence of stress disorder and chronic fatigue problems. A total of 120 patients were enrolled. The prevalence rate of fatigue symptoms was 17.5%. Twelve (10%) screened positive for chronic idiopathic fatigue (CIF), 6 (5%) for CFS-like with insufficient fatigue syndrome (CFSWIFS), and 3 (2.5%) for CFS. The mean total scores in PCL-5 were 9.27 ± 10.76 (range:0-44), and the prevalence rate of PTSD was 5.8%. There was no significant association after adjusting between CFS and PTSD, gender, comorbidities, and chloroquine phosphate administration.

The obtained data revealed the prevalence of CFS among patients with COVID-19, which is almost similar to CFS prevalence in the general population. Moreover, PTSD in patients with COVID-19 is not associated with the increased risk of CFS. Our study suggested that medical institutions should pay attention to the psychological consequences of the COVID-19 outbreak.

Source: Simani L, Ramezani M, Darazam IA, Sagharichi M, Aalipour MA, Ghorbani F, Pakdaman H. Prevalence and correlates of chronic fatigue syndrome and post-traumatic stress disorder after the outbreak of the COVID-19. J Neurovirol. 2021 Feb 2:1–6. doi: 10.1007/s13365-021-00949-1. Epub ahead of print. PMID: 33528827; PMCID: PMC7852482.  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7852482/ (Full text)

Will COVID-19 Lead to ME/CFS?

INTRODUCTION:

“Recovering” from COVID-19 does not guarantee a return to a person’s usual state of health. For one thing, some people with multi-system injury—particularly to the brain, heart and kidneys—may develop permanent dysfunction of those organs.
In addition, a more subtle form of chronic illness may develop. For some people with COVID-19, even those who are mildly affected at first, the ensuing weeks and months of “recovery” bring a surprise and a betrayal: they do not return to full health. Although nucleic acid tests no longer detect the virus, people still suffer from ongoing symptoms. They call themselves “long haulers”, and the condition is being called “long COVID”.

Source: Anthony L. Komaroff and Lucinda Bateman. Will COVID-19 Lead to ME/CFS? Front. Med. | doi: 10.3389/fmed.2020.606824 https://www.frontiersin.org/articles/10.3389/fmed.2020.606824/full (Full text)

Risks for Developing ME/CFS in College Students Following Infectious Mononucleosis: A Prospective Cohort Study

Abstract:

Background: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) involves severe fatigue, unrefreshing sleep, and cognitive impairment, leading to functional difficulties; prior studies have not evaluated risk factors with behavioral and immune data collected prior to developing ME/CFS.. Up to 5% of university students develop infectious mononucleosis (IM) annually, and 9-12% meet criteria for ME/CFS six months later. We sought to determine predictors of ME/CFS.

Methods: We enrolled college students at the start of the school year (Time 1), identified those who developed IM (Time 2) and followed them for 6 months (Time 3), identifying three groups: those who developed ME/CFS, those who developed severe ME/CFS (meeting >1 set of criteria) and those who were asymptomatic. We conducted 8 behavioral and psychological surveys and analyzed cytokines at three time points.

Results: 238 of the 4501 students (5.3%) developed IM; 6 months later, 55 of the 238 (23%) met criteria for ME/CFS and 157 (66%) were asymptomatic. 67 of the 157 asymptomatic students served as controls. Students with severe-ME/CFS were compared to students who were asymptomatic at three time points. The former group was not different from the latter group at Time 1 (prior to developing IM) in stress, coping, anxiety or depression, but were different in several behavioral measures and had significantly lower levels of IL-6 and IL-13. At Time 2 (when they developed IM), the two ME/CFS groups tended to have more autonomic complaints and behavioral symptoms while the severe- ME/CFS group had higher levels of IL-12 and lower levels of IL-13 than the recovered group.

Conclusion: At baseline, those who developed ME/CFS had more physical symptoms and immune irregularities, but not more psychological symptoms, than those who recovered.

Source: Leonard A Jason, PhD, Joseph Cotler, PhD, Mohammed F Islam, PhD, Madison Sunnquist, PhD, Ben Z Katz, MD, Risks for Developing ME/CFS in College Students Following Infectious Mononucleosis: A Prospective Cohort Study, Clinical Infectious Diseases, , ciaa1886, https://doi.org/10.1093/cid/ciaa1886

A systematic review of metabolomic dysregulation in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis/Systemic Exertion Intolerance Disease

Abstract:

BACKGROUND: Chronic Fatigue Syndrome/Myalgic Encephalomyelitis/Systemic Exertion Intolerance Disease (CFS/ME/SEID) is a complex illness that has an unknown aetiology. It has been proposed that metabolomics may contribute to the illness pathogenesis of CFS/ME/SEID. In metabolomics, the systematic identification of measurable changes in small molecule metabolite products have been identified in cases of both monogenic and heterogenic diseases. Therefore, the aim of this systematic review was to evaluate if there is any evidence of metabolomics contributing to the pathogenesis of CFS/ME/SEID.

METHODS: PubMed, Scopus, EBSCOHost (Medline) and EMBASE were searched using medical subject headings terms for Chronic Fatigue Syndrome, metabolomics and metabolome to source papers published from 1994 to 2020. Inclusion and exclusion criteria were used to identify studies reporting on metabolites measured in blood and urine samples from CFS/ME/SEID patients compared with healthy controls. The Joanna Briggs Institute Checklist was used to complete a quality assessment for all the studies included in this review.

RESULTS: 11 observational case control studies met the inclusion criteria for this review. The primary outcome of metabolite measurement in blood samples of CFS/ME/SEID patients was reported in ten studies. The secondary outcome of urine metabolites was measured in three of the included studies. No studies were excluded from this review based on a low-quality assessment score, however there was inconsistency in the scientific research design of the included studies. Metabolites associated with the amino acid pathway were the most commonly impaired with significant results in seven out of the 10 studies. However, no specific metabolite was consistently impaired across all of the studies. Urine metabolite results were also inconsistent.

CONCLUSION: The findings of this systematic review reports that a lack of consistency with scientific research design provides little evidence for metabolomics to be clearly defined as a contributing factor to the pathogenesis of CFS/ME/SEID. Further research using the same CFS/ME/SEID diagnostic criteria, metabolite analysis method and control of the confounding factors that influence metabolite levels are required.

Source: Huth TK, Eaton-Fitch N, Staines D, Marshall-Gradisnik S. A systematic review of metabolomic dysregulation in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis/Systemic Exertion Intolerance Disease (CFS/ME/SEID). J Transl Med. 2020 May 13;18(1):198. doi: 10.1186/s12967-020-02356-2. https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-020-02356-2 (Full text)

HERV-K and HERV-W transcriptional activity in myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

BACKGROUND: Chronic fatigue syndrome/myalgic encephalomyelitis (CFS/MS) is an incapacitating chronic disease that dramatically compromise the life quality. The CFS/ME pathogenesis is multifactorial, and it is believed that immunological, metabolic and environmental factors play a role. It is well documented an increased activity of Human endogenous retroviruses (HERVs) from different families in autoimmune and neurological diseases, making these elements good candidates for biomarkers or even triggers for such diseases.

METHODS: Here the expression of Endogenous retroviruses K and W (HERV-K and HERV-W) was determined in blood from moderately and severely affected ME/CFS patients through real time PCR.

RESULTS: HERV-K was overexpressed only in moderately affected individuals but HERV-W showed no difference.

CONCLUSIONS: This is the first report about HERV-K differential expression in moderate ME/CFS. Although the relationship between HERVs and ME/CFS has yet to be proven, the observation of this phenomenon deserves further attention.

Source: Rodrigues LS, da Silva Nali LH, Leal COD, Sabino EC, Lacerda EM, Kingdon CC, Nacul L, Romano CM. HERV-K and HERV-W transcriptional activity in myalgic encephalomyelitis/chronic fatigue syndrome. Auto Immun Highlights. 2019 Nov 15;10(1):12. doi: 10.1186/s13317-019-0122-8. eCollection 2019 Dec. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7065355/ (Full text)

Human Leukocyte Antigen alleles associated with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)

Abstract:

The etiology and pathogenesis of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) are unknown, and autoimmunity is one of many proposed underlying mechanisms. Human Leukocyte Antigen (HLA) associations are hallmarks of autoimmune disease, and have not been thoroughly investigated in a large ME/CFS patient cohort.

We performed high resolution HLA -A, -B, -C, -DRB1, -DQB1 and -DPB1 genotyping by next generation sequencing in 426 adult, Norwegian ME/CFS patients, diagnosed according to the Canadian Consensus Criteria. HLA associations were assessed by comparing to 4511 healthy and ethnically matched controls. Clinical information was collected through questionnaires completed by patients or relatives.

We discovered two independent HLA associations, tagged by the alleles HLA-C*07:04 (OR 2.1 [95% CI 1.4-3.1]) and HLA-DQB1*03:03 (OR 1.5 [95% CI 1.1-2.0]). These alleles were carried by 7.7% and 12.7% of ME/CFS patients, respectively. The proportion of individuals carrying one or both of these alleles was 19.2% in the patient group and 12.2% in the control group (OR 1.7 [95% CI 1.3-2.2], pnc = 0.00003). ME/CFS is a complex disease, potentially with a substantial heterogeneity. We report novel HLA associations pointing toward the involvement of the immune system in ME/CFS pathogenesis.

Source: Lande A, Fluge Ø, Strand EB, Flåm ST, Sosa DD, Mella O, Egeland T, Saugstad OD, Lie BA, Viken MK. Human Leukocyte Antigen alleles associated with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). Sci Rep. 2020 Mar 24;10(1):5267. doi: 10.1038/s41598-020-62157-x. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7093502/ (Full text)

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome as a Hyper-Regulated Immune System Driven by an Interplay Between Regulatory T Cells and Chronic Human Herpesvirus Infections

Abstract:

Autoimmunity and chronic viral infections are recurrent clinical observations in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), a complex disease with an unknown cause. Given these observations, the regulatory CD4+ T cells (Tregs) show promise to be good candidates for the underlying pathology due to their capacity to suppress the immune responses against both self and microbial antigens. Here, we discussed the overlooked role of these cells in the chronicity of Human Herpes Virus 6 (HHV6), Herpes Simplex 1 (HSV1), and Epstein-Barr virus (EBV), as often reported as triggers of ME/CFS.

Using simulations of the cross-regulation model for the dynamics of Tregs, we illustrated that mild infections might lead to a chronically activated immune responses under control of Tregs if the responding clone has a high autoimmune potential. Such infections promote persistent inflammation and possibly fatigue. We then hypothesized that ME/CFS is a condition characterized by a predominance of this type of infections under control of Tregs. In contrast, healthy individuals are hypothesized to trigger immune responses of a virus-specific clone with a low autoimmune potential.

According to this hypothesis, simple model simulations of the CD4+ T-cell repertoire could reproduce the increased density and percentages of Tregs observed in patients suffering from the disease, when compared to healthy controls. A deeper analysis of Tregs in the pathogenesis of ME/CFS will help to assess the validity of this hypothesis.

Copyright © 2019 Sepúlveda, Carneiro, Lacerda and Nacul.

Source: Sepúlveda N, Carneiro J, Lacerda E, Nacul L. Myalgic Encephalomyelitis/Chronic Fatigue Syndrome as a Hyper-Regulated Immune System Driven by an Interplay Between Regulatory T Cells and Chronic Human Herpesvirus Infections. Front Immunol. 2019 Nov 21;10:2684. doi: 10.3389/fimmu.2019.02684. eCollection 2019. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6883905/ (Full article)