Post-corona fatigue-a familiar picture in a new guise?

Abstract:

Background: Myalgic encephalitis or chronic fatigue syndrome (ME/CFS) has again come into focus as a result of coronavirus disease 2019 (COVID-19). Fundamentally problematic is the fact that ME/CFS is considered a separate entity; however, extreme fatigue is also a common symptom of an underlying disease. Our article aims to increase the acceptance of ME/CFS and extreme fatigue facing a symptomatology that is not fully understood, and to highlight the need for research, orientation for physicians, and counselling services for patients.

Materials and methods: Orientative research by focused information gathering.

Results: In various research projects, the hypothesis of post-infectious ME/CFS as an autoimmune disease could be confirmed. In general, the heterogeneity of diagnostic criteria as well as the variety of formulations to describe the symptomatology and different coding options make it difficult to clearly assign symptoms to a clinical picture. Exertion intolerance has been identified as a severe symptom of post-COVID-19 disorder. For this reason, recommendations in international guidelines are currently being revised, especially with regard to pacing. The implications for recommendations in tumor-related fatigue or due to multiple sclerosis are unclear.

Conclusion: Against the background of a decreasing burden of disease due to increasing vaccination rates, research on fatigue should not only include viral diseases.

Source: Buchberger B, Zwierlein R, Rohde V. Post-Corona-Fatigue – das bekannte Bild in neuem Gewand? [Post-corona fatigue-a familiar picture in a new guise?]. Onkologe (Berl). 2022 Feb 17:1-6. German. doi: 10.1007/s00761-022-01102-1. Epub ahead of print. PMID: 35194336; PMCID: PMC8853121. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8853121/ (Article in German) (Full text)

Commonalities in the Features of Cancer and Chronic Fatigue Syndrome (CFS): Evidence for Stress-Induced Phenotype Instability?

Abstract:

Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME) and Cancer-Related Fatigue (CRF) are syndromes with considerable overlap with respect to symptoms. There have been many studies that have compared the two conditions, and some of this research suggests that the etiologies of the conditions are linked in some cases. In this narrative review, CFS/ME and cancer are introduced, along with their known and putative mechanistic connections to multiple stressors including ionizing radiation.

Next, we summarize findings from the literature that suggest the involvement of HPA-axis dysfunction, the serotonergic system, cytokines and inflammation, metabolic insufficiency and mitochondrial dysfunction, and genetic changes in CRF and CFS/ME. We further suspect that the manifestation of fatigue in both diseases and its causes could indicate that CRF and CFS/ME lie on a continuum of potential biological effects which occur in response to stress. The response to this stress likely varies depending on predisposing factors such as genetic background.

Finally, future research ideas are suggested with a focus on determining if common biomarkers exist in CFS/ME patients and those afflicted with CRF. Both CFS/ME and CRF are relatively heterogenous syndromes, however, it is our hope that this review assists in future research attempting to elucidate the commonalities between CRF and CFS/ME.

Source: Rusin A, Seymour C, Cocchetto A, Mothersill C. Commonalities in the Features of Cancer and Chronic Fatigue Syndrome (CFS): Evidence for Stress-Induced Phenotype Instability? Int J Mol Sci. 2022 Jan 8;23(2):691. doi: 10.3390/ijms23020691. PMID: 35054876. https://pubmed.ncbi.nlm.nih.gov/35054876/

Inflammation plays a causal role in fatigue-like behavior induced by pelvic irradiation in mice

Abstract:

Fatigue is a persistent and debilitating symptom following radiation therapy for prostate cancer. However, it is not well-understood how radiation targeted to a small region of the body can lead to broad changes in behavior. In this study, we used targeted pelvic irradiation of healthy male mice to test whether inflammatory signaling mediates changes in voluntary physical activity levels.

First, we tested the relationship between radiation dose, blood cell counts, and fatigue-like behavior measured as voluntary wheel-running activity. Next, we used oral minocycline treatments to reduce inflammation and found that minocycline reduces, but does not eliminate, the fatigue-like behavioral changes induced by radiation. We also used a strain of mice lacking the MyD88 adaptor protein and found that these mice also showed less fatigue-like behavior than the wild-type controls. Finally, using serum and brain tissue samples, we determined changes in inflammatory signaling induced by irradiation in wild-type, minocycline treated, and MyD88 knockout mice.

We found that irradiation increased serum levels of IL-6, a change that was partially reversed in mice treated with minocycline or lacking MyD88. Overall, our results suggest that inflammation plays a causal role in radiation-induced fatigue and that IL-6 may be an important mediator.

Source: Wolff BS, Alshawi SA, Feng LR, Juneau PL, Saligan LN. Inflammation plays a causal role in fatigue-like behavior induced by pelvic irradiation in mice. Brain Behav Immun Health. 2021 May 19;15:100264. doi: 10.1016/j.bbih.2021.100264. PMID: 34589770; PMCID: PMC8474574. https://pubmed.ncbi.nlm.nih.gov/34589770/

Multidimensional Comparison of Cancer-Related Fatigue and Chronic Fatigue Syndrome: The Role of Psychophysiological Markers

Abstract:

OBJECTIVE: The present study compared cancer-related fatigue (CRF) and chronic fatigue syndrome (CFS) using multidimensional measurements with the aim of better understanding characteristics and exploring markers of two similar fatigue syndromes.

METHODS: Twenty-five patients with CRF and twenty patients with CFS completed questionnaires, including the Fatigue Severity Scale (FSS), Hospital Anxiety Depression Scale (HADS), Perceived Stress Scale (PSS), and Pittsburgh Sleep Quality Index (PSQI). Additionally, levels of high sensitivity C-reactive protein (hs-CRP), heart rate variability (HRV), and electroencephalography (EEG) were obtained. Neurocognitive functioning was also evaluated.

RESULTS: Both groups showed comparable levels of psychological variables, including fatigue. Compared to CFS subjects, CRF patients had significantly higher hs-CRP levels and a reduced HRV-index. The within-group analyses revealed that the FSS score of the CRF group was significantly related to scores on the HADS-anxiety, HADS-depression, and PSQI scales. In the CFS group, FSS scores were significantly associated with scores on the PSS and the absolute delta, theta, and alpha powers in frontal EEG.

CONCLUSION: Findings indicate that different pathophysiological mechanisms underlie CFS and CRF. Inflammatory marker and HRV may be potential biomarkers for distinguishing two fatigue syndromes and frontal EEG parameters may be quantitative biomarkers for CFS.

Source: Park HY, Jeon HJ, Bang YR, Yoon IY. Multidimensional Comparison of Cancer-Related Fatigue and Chronic Fatigue Syndrome: The Role of Psychophysiological Markers. Psychiatry Investig. 2019 Jan 7. doi: 10.30773/pi.2018.10.26. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/30605994

The High Costs of Low-Grade Inflammation: Persistent Fatigue as a Consequence of Reduced Cellular-Energy Availability and Non-adaptive Energy Expenditure

Abstract:

Chronic or persistent fatigue is a common, debilitating symptom of several diseases. Persistent fatigue has been associated with low-grade inflammation in several models of fatigue, including cancer-related fatigue and chronic fatigue syndrome. However, it is unclear how low-grade inflammation leads to the experience of fatigue. We here propose a model of an imbalance in energy availability and energy expenditure as a consequence of low-grade inflammation.

In this narrative review, we discuss how chronic low-grade inflammation can lead to reduced cellular-energy availability. Low-grade inflammation induces a metabolic switch from energy-efficient oxidative phosphorylation to fast-acting, but less efficient, aerobic glycolytic energy production; increases reactive oxygen species; and reduces insulin sensitivity. These effects result in reduced glucose availability and, thereby, reduced cellular energy.

In addition, emerging evidence suggests that chronic low-grade inflammation is associated with increased willingness to exert effort under specific circumstances. Circadian-rhythm changes and sleep disturbances might mediate the effects of inflammation on cellular-energy availability and non-adaptive energy expenditure.

In the second part of the review, we present evidence for these metabolic pathways in models of persistent fatigue, focusing on chronic fatigue syndrome and cancer-related fatigue. Most evidence for reduced cellular-energy availability in relation to fatigue comes from studies on chronic fatigue syndrome. While the mechanistic evidence from the cancer-related fatigue literature is still limited, the sparse results point to reduced cellular-energy availability as well.

There is also mounting evidence that behavioral-energy expenditure exceeds the reduced cellular-energy availability in patients with persistent fatigue. This suggests that an inability to adjust energy expenditure to available resources might be one mechanism underlying persistent fatigue.

Source: Lacourt TE, Vichaya EG, Chiu GS, Dantzer R, Heijnen CJ. The High Costs of Low-Grade Inflammation: Persistent Fatigue as a Consequence of Reduced Cellular-Energy Availability and Non-adaptive Energy Expenditure. Front Behav Neurosci. 2018 Apr 26;12:78. doi: 10.3389/fnbeh.2018.00078. eCollection 2018.  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5932180/ (Full article)

A systematic review of the association between fatigue and genetic polymorphisms

Abstract:

Fatigue is one of the most common and distressing symptoms, leading to markedly decreased quality of life among a large subset of patients with a variety of disorders. Susceptibility to fatigue may be influenced by genetic factors including single nucleotide polymorphisms (SNPs), especially in the regulatory regions, of relevant genes.

To further investigate the association of SNPs with fatigue in various patient populations, a systematic search was conducted on Pubmed, CINAHL, PsycINFO, and Sociological Abstracts Database for fatigue related-terms in combination with polymorphisms or genetic variation-related terms. Fifty papers in total met the inclusion and exclusion criteria for this analysis. These 50 papers were further classified into three subgroups for evaluation: chronic fatigue syndrome (CFS), cancer-related fatigue (CRF) and other disease-related fatigue.

SNPs in regulatory pathways of immune and neurotransmitter systems were found to play important roles in the etiologies of CFS, CRF and other disease-related fatigue. Evidence for associations between elevated fatigue and specific polymorphisms in TNFα, IL1b, IL4 and IL6 genes was revealed for all three subgroups of fatigue.

We also found CFS shared a series of polymorphisms in HLA, IFN-γ, 5-HT and NR3C1 genes with other disease-related fatigue, however these SNPs (excluding IFN-γ) were not found to be adequately investigated in CRF. Gaps in knowledge related to fatigue etiology and recommendations for future research are further discussed.

Copyright © 2017 Elsevier Inc. All rights reserved.

 

Source: Wang T, Yin J, Miller AH, Xiao C. A systematic review of the association between fatigue and genetic polymorphisms. Brain Behav Immun. 2017 Jan 12. pii: S0889-1591(17)30007-7. doi: 10.1016/j.bbi.2017.01.007. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/28089639

 

Differing leukocyte gene expression profiles associated with fatigue in patients with prostate cancer versus chronic fatigue syndrome

Abstract:

BACKGROUND: Androgen deprivation therapy (ADT) often worsens fatigue in patients with prostate cancer, producing symptoms similar to chronic fatigue syndrome (CFS). Comparing expression (mRNA) of many fatigue-related genes in patients with ADT-treated prostate cancer versus with CFS versus healthy controls, and correlating mRNA with fatigue severity may clarify the differing pathways underlying fatigue in these conditions.

METHODS: Quantitative real-time PCR was performed on leukocytes from 30 fatigued, ADT-treated prostate cancer patients (PCF), 39 patients with CFS and 22 controls aged 40-79, together with ratings of fatigue and pain severity. 46 genes from these pathways were included: (1) adrenergic/monoamine/neuropeptides, (2) immune, (3) metabolite-detecting, (4) mitochondrial/energy, (5) transcription factors.

RESULTS: PCF patients showed higher expression than controls or CFS of 2 immune transcription genes (NR3C1 and TLR4), chemokine CXCR4, and mitochondrial gene SOD2. They showed lower expression of 2 vasodilation-related genes (ADRB2 and VIPR2), 2 cytokines (TNF and LTA), and 2 metabolite-detecting receptors (ASIC3 and P2RX7). CFS patients showed higher P2RX7 and lower HSPA2 versus controls and PCF. Correlations with fatigue severity were similar in PCF and CFS for only DBI, the GABA-A receptor modulator (r=-0.50, p<0.005 and r=-0.34, p<0.05). Purinergic P2RY1 was correlated only with PCF fatigue and pain severity (r=+0.43 and +0.59, p=0.025 and p=0.001).

CONCLUSIONS: PCF patients differed from controls and CFS in mean expression of 10 genes from all 5 pathways. Correlations with fatigue severity implicated DBI for both patient groups and P2RY1 for PCF only. These pathways may provide new targets for interventions to reduce fatigue.

Copyright © 2013 Elsevier Ltd. All rights reserved.

 

Source: Light KC, Agarwal N, Iacob E, White AT, Kinney AY, VanHaitsma TA, Aizad H, Hughen RW, Bateman L, Light AR. Differing leukocyte gene expression profiles associated with fatigue in patients with prostate cancer versus chronic fatigue syndrome. Psychoneuroendocrinology. 2013 Dec;38(12):2983-95. doi: 10.1016/j.psyneuen.2013.08.008. Epub 2013 Sep 6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3848711/ (Full article)

 

Chronic Fatigue Syndrome (CFS) and Cancer Related Fatigue (CRF): two “fatigue” syndromes with overlapping symptoms and possibly related aetiologies

Abstract:

In July 2010, at the Muscle Fatigue Meeting, I presented an overview of Chronic Fatigue Syndrome and Cancer Related Fatigue, emphasizing a critical interpretation of the potential association between Chronic Fatigue Syndrome and Cancer Related Fatigue and a newly discovered retrovirus: Xenotropic Murine Related Virus. Since this association was hotly debated at that time, I suggested at the Meeting that it was wrong and most likely due to the identification of the wrong virus culprit.

Today, 20 months after the Meeting, the first part of our prediction has turned out to be correct, as Xenotropic Murine Related Virus was shown to be a laboratory-created artefact. Still, the potential association of fatigue-syndromes with an infection (most likely viral) is sustained by a plethora of evidence and this overview will initially summarize data suggesting prior viral infection(s). The principal hypothesized mechanisms for both peripheral and central Chronic Fatigue Syndrome/Cancer Related Fatigue will be then summarized, also indicating plausible associations and triggering factors.

All evidence accrued so far suggests that further research work should be performed in this interesting area and in order to identify an infectious agent for Chronic Fatigue Syndrome/Cancer Related Fatigue. One candidate RNA virus, Micro-Foci inducing Virus, will be described in this overview.

Copyright © 2012 Elsevier B.V. All rights reserved.

 

Source: Rovigatti U. Chronic Fatigue Syndrome (CFS) and Cancer Related Fatigue (CRF): two “fatigue” syndromes with overlapping symptoms and possibly related aetiologies. Neuromuscul Disord. 2012 Dec;22 Suppl 3:S235-41. doi: 10.1016/j.nmd.2012.10.018. https://www.ncbi.nlm.nih.gov/pubmed/23182646