Blood virome research in myalgic encephalomyelitis/chronic fatigue syndrome: challenges and opportunities

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating disease with a complex clinical presentation and an unknown etiology. Various viral infections have been proposed as potential triggers of ME/CFS onset, but no specific pathogen has been identified in all cases of postinfectious ME/CFS.

The symptomatology of the postacute sequelae of SARS-CoV-2, or long COVID, mirrors that of ME/CFS, with nearly half of long COVID patients meeting ME/CFS diagnostic criteria. The influx of newly diagnosed patients has reinvigorated interest in ME/CFS pathogenesis research, with an emphasis on viral triggers.

This review summarizes the current understanding of ME/CFS research on viral triggers, including blood virome screening studies. To further elucidate the molecular basis of ME/CFS, there is a need to develop innovative bioinformatics tools capable of analyzing complex virome data and integrating multiomics information.

Source: Obraitis D, Li D. Blood virome research in myalgic encephalomyelitis/chronic fatigue syndrome: challenges and opportunities. Curr Opin Virol. 2024 Nov 12:101437. doi: 10.1016/j.coviro.2024.101437. Epub ahead of print. PMID: 39537445. https://www.sciencedirect.com/science/article/pii/S1879625724000518 (Full text)

Chronic Fatigue Syndrome, Viruses and Related Conditions in Women: The Liver Link

Abstract:

Chronic Fatigue Syndrome (CFS) can be triggered by different factors and create a complex health situation. In the last decades incidence has been increasing. This situation is a clear example of how humans, viruses, and the environment are all connected.
In the 90s cases related to CFS, complaints about a feeling of chronic fatigue, inability for everyday tasks, dull pain, cephalalgia, de-pression, anxiety, poor concentration. Clinical tests for EBV, HHV, CMV, IgG, IgM, T4 and T8 subsets were tested, along with hormones and hemogram tests. Most of the cases were women. The timeline of the medical history showed also myomas, breast lumps, premenstrual syndrome previously to CFS development. The nature of these conditions promoted the idea of a possible common link among them and CFS. Some cases also suffered from allergies, food intolerances, candidiasis, intestinal impairment, thyroid implications, endometriosis.
As an initial working hypothesis, The Liver Link (TLL) was proposed in order to understand those different conditions affecting body, mind and emotional wellbeing. Considering liver implication can make a difference in treatment and recovery. Low grade inflammatory conditions are related to Th2 predominance and liver functions. Functional disharmonies are very important because they usually still do not appear in any conventional tests.
In 2002, TLL was presented as a framework to explain the concomitance of CFS and other conditions and the relationship with some viruses such as EBV, HHV, CMV, as a lecture in a congress at the University of Westminster (London). When SARS-CoV-2 outbroke, TLL helped to warn about the post-covid syndrome more likely to occur in specific individuals.
Source: Lorite-Ayán, N. Chronic Fatigue Syndrome, Viruses and Related Conditions in Women: The Liver Link. Preprints 2024, 2024011654. https://doi.org/10.20944/preprints202401.1654.v1 https://www.preprints.org/manuscript/202401.1654/v1 (Full text available as PDF file)

Comprehensive profiling of the human intestinal DNA virome and prediction of disease-associated bacterial hosts in severe Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a disabling disorder of unknown etiology with severely affected patients being house- and/or bedbound. A historical association with chronic virus infection and subsequent recent reports correlating intestinal microbial dysbiosis with disease pathology prompted us to analyze the intestinal virome in a small cohort of severely-affected ME/CFS patients and same household healthy controls (SHHC).

Datasets from whole metagenomic sequencing (WMS) and sequencing of virus-like particles (VLP)-enriched metagenomes from the same fecal sample yielded diverse, high-quality vOTUs with high read coverage and high genome completeness. The core intestinal virome was largely composed of tailed phages in the class Caudoviricetes with no significant differences in alpha diversity between ME/CFS and SHHC groups. However, the WMS dataset had a higher Shannon measure than the VLP dataset (p < 0.0001), with VLP- and WMS-derived sequences indicating differential abundances within several viral families and different viral compositions in beta diversity.

This confirms that combining different isolation methodologies identifies a greater diversity of viruses including extracellular phages and integrated prophages. DNA viromes and bacteriomes from ME/CFS and SHHC groups were comparable with no differences in any alpha or beta diversity measures. One vOTU derived from the VLP-derived dataset was assigned to ssDNA human virus smacovirus 1. Using an in-silico approach to predict cohort-based bacterial hosts, we identified members of the Anaerotruncus genus interacting with unique viruses present in ME/CFS microbiomes; this may contribute to the GI microbial dysbiosis described in ME/CFS patients.

Source: Shen-Yuan HsiehGeorge M SavvaAndrea TelatinSumeet K TiwariMohammad A TariqFiona NewberryKatharine A SetonCatherine BoothAmolak S BansalTom WilemanEvelien AndriaenssensSimon R Carding. Comprehensive profiling of the human intestinal DNA virome and prediction of disease-associated bacterial hosts in severe Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).

What Causes ME/CFS: The Role of the Dysfunctional Immune System and Viral Infections

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) remains an enigmatic highly disabling and complex long-term condition with a wide range of aetiologies and symptoms.

A viral onset is commonly mentioned by patients and several bodily systems are ultimately disturbed. The parallel with long-covid is clear.

However, immune dysregulation with impaired NK cell dysfunction and tendency to novel autoimmunity have been frequently reported. These may contribute to reactivation of previous acquired viruses/retroviruses accompanied by impaired endocrine regulation and mitochondrial energy generation.

The unpredictable nature of seemingly unconnected and diverse symptoms that are poorly responsive to several allopathic and alternative therapies then contributes to an escalation of the illness with secondary dysfunction of multiple other systems. Treatment of established ME/CFS is therefore difficult and requires multi-specialty input addressing each of the areas affected by the illness.

Source: Amolak S Bansal, Aletta D Kraneveld, Elisa Oltra and Simon Carding. What Causes ME/CFS: The Role of the Dysfunctional Immune System and Viral Infections. Journal of Immunology and Allergy 2022;3(2):1-15. https://maplespub.co.in/assets/images/files/doc_1663924267.pdf (Full text)

Viral diseases and the brain: Long COVID puts the spotlight on how viral infections affect the brain

Abstract:

Various viruses can affect the brain directly or indirectly. The specter of Long COVID has focused research on how respiratory viruses can cause infection and inflammation of brain cells.

Source: Hunter P. Viral diseases and the brain: Long COVID puts the spotlight on how viral infections affect the brain. EMBO Rep. 2021 Nov 29:e54342. doi: 10.15252/embr.202154342. Epub ahead of print. PMID: 34842325. https://pubmed.ncbi.nlm.nih.gov/34842325/

Long COVID Patient Symptoms and its Evaluation and Management

Abstract:

While the acute case burdens and deaths from the COVID-19 pandemic (in Nepal approaching 700,000 and 10,000 respectively) have been costly, the characteristics and potentially huge dimensions of the chronic disease sequelae of this infectious disease are only slowly becoming apparent. We reviewed Pub Med, major medical meeting and medical journal, and investigative journalist materials seeking to frame and describe COVID-19 chronic disease.

The consequences of COVID-19 infections follow major organ damage, and induction of immunological and hormonal systems dysfunction. The first injuries are consequent to direct viral effects on tissues, and vasculitis, endothelialitis, thrombosis and inflammatory events. Pulmonary, cardiac, brain, and kidney tissues incur function-limiting damage, with dyspnea, arrythmias, decreased exercise capacity, cognitive dysfunction, and decreased glomerular filtration rates.

The second process is characterized by immune dysregulation and autoimmunity, and dysfunction of hormonal regulation systems, with high, fluctuating levels of physical and mental fatigue, multiple-site pain and ache, and non-restorative sleep, in 10-30% of cases.

This communication proposes evaluation and management of chronic COVID-19 patients with efficient assessment of commonest symptoms, targeted physical examination and organ function testing, and interventions based on specific organ functional status, and experience with similar chronic immune syndromes, such as myalgic encephalomyelitis.

Source: Sundar Shrestha D, Love R. Long COVID Patient Symptoms and its Evaluation and Management. JNMA J Nepal Med Assoc. 2021 Aug 12;59(240):823-831. doi: 10.31729/jnma.6355. PMID: 34508486. https://pubmed.ncbi.nlm.nih.gov/34508486/

Rheumatism and chronic fatigue, the two facets of post-chikungunya disease: the TELECHIK cohort study on Reunion island

Abstract:

Prolonged fatigue is increasingly reported among chikungunya virus (CHIKV)-infected populations. We investigated the relationships between CHIKV exposure, long-lasting rheumatic musculoskeletal pain (LRMSP) and chronic fatigue. 1094 participants (512 CHIKV seropositive and 582 seronegative) of the TELECHIK population-based cohort were analysed considering the duration of the manifestations throughout an average 2-year follow-up.

Weighted prevalence rates and prevalence ratios for LRMSP, idiopathic chronic fatigue (ICF), and chronic fatigue syndrome (CFS)-like illness, both latter syndromes adapted from Centers for Disease Control (CDC)-1994/Fukuda criteria, were compared. Population attributable fractions (PAF) were estimated to assess the contribution of CHIKV infection to each of the three phenotypes.

Among 362 adult subjects who had reported either rheumatic pain or fatigue at the onset of the infection, weighted prevalence rates of LRMSP, ICF and CFS-like illness were respectively of 32.9%, 38.7% and 23.9%, and of 8.7%, 8.5% and 7.4% among initially asymptomatic peers (P < 0.01, respectively). Each of the three outcomes was highly attributable to chikungunya (PAF of 43.2%, 36.2% and 41.0%, respectively).

In the sub-cohort of CHIKV-infected subjects, LRMSP, ICF and CFS-like illness, which overlapped in 70%, accounted for 53% of the chronic manifestations. In addition to rheumatic disease, chronic fatigue could be considered in caring for patients with chronic chikungunya disease.

Source: Duvignaud A, Fianu A, Bertolotti A, Jaubert J, Michault A, Poubeau P, Fred A, Méchain M, Gaüzère BA, Favier F, Malvy D, Gérardin P. Rheumatism and chronic fatigue, the two facets of post-chikungunya disease: the TELECHIK cohort study on Reunion island. Epidemiol Infect. 2018 Feb 28:1-9. doi: 10.1017/S0950268818000031. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/29486812

In vitro effects of echinacea and ginseng on natural killer and antibody-dependent cell cytotoxicity in healthy subjects and chronic fatigue syndrome or acquired immunodeficiency syndrome patients

Abstract:

Extracts of Echinacea purpurea and Panax ginseng were evaluated for their capacity to stimulate cellular immune function by peripheral blood mononuclear cells (PBMC) from normal individuals and patients with either the chronic fatigue syndrome or the acquired immunodeficiency syndrome.

PBMC isolated on a Ficoll-hypaque density gradient were tested in the presence or absence of varying concentrations of each extract for natural killer (NK) cell activity versus K562 cells and antibody-dependent cellular cytotoxicity (ADCC) against human herpesvirus 6 infected H9 cells. Both echinacea and ginseng, at concentrations > or = 0.1 or 10 micrograms/kg, respectively, significantly enhanced NK-function of all groups. Similarly, the addition of either herb significantly increased ADCC of PBMC from all subject groups.

Thus, extracts of Echinacea purpurea and Panax ginseng enhance cellular immune function of PBMC both from normal individuals and patients with depressed cellular immunity.

 

Source: See DM, Broumand N, Sahl L, Tilles JG. In vitro effects of echinacea and ginseng on natural killer and antibody-dependent cell cytotoxicity in healthy subjects and chronic fatigue syndrome or acquired immunodeficiency syndrome patients. Immunopharmacology. 1997 Jan;35(3):229-35. http://www.ncbi.nlm.nih.gov/pubmed/9043936

 

Chronic fatigue syndrome: a critical review

Abstract:

The term “chronic fatigue syndrome” (CFS) applies to a condition of unknown aetiology characterized clinically by an association of subjective symptoms, the most constant being an invalidating tiredness. The diagnostic criteria in current use do not permit to isolate an homogeneous subgroup among patients consulting for chronic asthenia.

In the present state of research no infectious or immunological cause has been demonstrated conclusively, although a persistent enterovirus or herpesvirus type 6 infection or a state of chronic immune activation seem to play a role in some cases. Patients who fulfill the criteria of CFS present with psychiatric overmorbidity, essentially depressive, and in 50% of the cases with the mental disorders preceding CFS. The various theoretical models linking CFS to psychopathology are discussed, and finally the syndrome is regarded as a social construction reproducing or renovating the neurasthenia of the late 19th century.

There is no specific treatment of CFS, but antidepressants, cognitive-behavioural therapy and perhaps certain immuno-modulators can be useful. The future lines of research should endeavour to isolate a subgroup of patients with prolonged asthenia after a recognized episode of infection and to identify the immunological, psychological and behavioral characteristics of this particular group as well as their reciprocal interactions.

 

Source: Cathébras P, Bouchou K, Charmion S, Rousset H. Chronic fatigue syndrome: a critical review. Rev Med Interne. 1993 Apr;14(4):233-42. [Article in French] http://www.ncbi.nlm.nih.gov/pubmed/8378654