Letter: Could endothelial dysfunction and vascular damage contribute to pain, inflammation and post-exertional malaise in individuals with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)?

To the Editor,

In their hypothesis paper, Wirth, Scheibenbogen, and Paul describe how endothelial dysfunction could produce a wide range of neurological symptoms in people with ME/CFS [1]. As they and others work to refine their understanding of ME/CFS and the related Long COVID syndrome, I would encourage consideration of the possibility that endothelial dysfunction and vascular damage could also explain other symptoms, including widespread pain and inflammation and post-exertional malaise.

For the past four years, my wife and I have been caregivers for our teenage daughter, who has ME/CFS, hypermobile Ehlers-Danlos syndrome, craniocervical instability, Chiari malformation and several other comorbid conditions. Through observation and trial and error, I have developed a number of hypotheses on these matters that I offer here in the hope they might prompt formal research into how to effectively treat these conditions [2].

Widespread pain and inflammation

Discussion of endothelial dysfunction and vascular damage in ME/CFS and Long COVID generally focuses on how leakages from dysfunctional blood vessels lead to reduced blood flow, which has many consequences, including reduced oxygenation of muscles and reduced cerebral brain flow. As researchers study this phenomenon, I would encourage consideration of the additional possibility that the leaking fluid causes independent damage. Lipedema researchers have found that leakages from microangiopathic blood vessels cause an excess of interstitial fluid that stimulates the formation of subcutaneous adipose tissue [3], which generates hypoxic conditions and becomes fibrotic, contributing to pain and inflammation [4].

I hypothesize that a similar process happens when fluid leaks from faulty blood vessels in ME/CFS, possibly exacerbated by endothelial dysfunction in lymphatic vessels that inhibit the fluid’s removal, causing widespread pain and inflammation. This mechanism appears most pronounced among people with hypermobility or other connective tissue disorders, a common trait among people with both ME/CFS and lipedema.

My daughter experiences pain from fibrotic adipose tissue as well as what appears to be nerve compression from accumulated interstitial / lymphatic fluid. Manual lymphatic drainage, the squeezing of affected tissue, and the manual break-up of fibrotic adipose tissue have helped to ameliorate these symptoms.

In my daughter, I have also observed impaired drainage of fluid from the glymphatic system, both at the cribriform plate and down her spine. Could this be related to damaged lymphatic vessels or blockages from fibrotic adipose tissue?

Post-exertional malaise

Like many people with moderate or severe ME/CFS, my daughter struggles to recover from even small amounts of physical exertion. In addition to mitigating her pain, manual lymphatic drainage and the squeezing of affected tissue greatly accelerates this recovery process. We have observed a direct dose–response relationship: the more exercise, the more fluid is present in her tissues, and the more manual draining / squeezing is necessary for her to recover.

Based on this experience, I hypothesize that excess interstitial fluid resulting from dysfunctional blood and lymphatic vessels contributes to the experience of post-exertional malaise, with fluid literally drowning affected tissue, leading to hypoxic conditions and inflammation. Possible explanations for the increased interstitial fluid are increases in blood pressure during physical exertion, hypermobile joints going out of place, prompting localized increases in interstitial fluid, and increases in cortisol that generate an increase in fluid and blood volume. Increases in fluid leakage due to elevated cortisol levels may also explain why some people with ME/CFS feel worse when stressed or anxious. The role of cortisol (or another mediator with fluid retaining properties) may explain why cognitive exertion can also generate post-exertional malaise. When present, elevated estrogen levels may exacerbate leakage by increasing fluid volume.

I am not sure why there is typically a delay between physical exertion and the experience of the most acute symptoms of post-exertional malaise. One possibility is that it takes time for the tissue inundated with fluid to feel the full effects of the hypoxic conditions. Another possibility is that a biphasic reaction triggered during physical exertion leads to the release of a mediator that causes heightened endothelial dysfunction and fluid release.

Further research is needed into the causes of endothelial dysfunction and damage (in addition to initial infection and inflammatory overreaction, consider major “crashes,” mast cell activations, surgeries and microclots as additional contributors) and appropriate treatment.

References

1. Wirth KJ, Scheibenbogen C, Paul F. An attempt to explain the neurological symptoms of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. J Transl Med. 2021;19:471. https://doi.org/10.1186/s12967-021-03143-3.

Article PubMed PubMed Central Google Scholar

2. For background, see Lubell, J. To speed progress in treating chronic conditions, engage patients and caregivers as research partners. 2021 Sept.20 In: BMJ Opinion. https://blogs.bmj.com/bmj/2021/09/20/to-speed-progress-in-treating-chronic-conditions-engage-patients-and-caregivers-as-research-partners/

3. Allen M, Schwartz M, Herbst KL. Interstitial Fluid in Lipedema and Control Skin. Womens Health Rep (New Rochelle). 2020;1(1):480–7. https://doi.org/10.1089/whr.2020.0086.PMID:33786515;PMCID:PMC7784769.

Article Google Scholar

4. Herbst KL. Subcutaneous Adipose Tissue Diseases: Dercum Disease, Lipedema, Familial Multiple Lipomatosis, and Madelung Disease. [Updated 2019 Dec 14]. In: Feingold KR, Anawalt B, Boyce A, et al., editors. South Dartmouth (MA).

Source: Lubell J. Letter: Could endothelial dysfunction and vascular damage contribute to pain, inflammation and post-exertional malaise in individuals with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)? J Transl Med. 2022 Jan 24;20(1):40. doi: 10.1186/s12967-022-03244-7. PMID: 35073915. https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-022-03244-7

Breast implant illness: scientific evidence of its existence

Abstract:

Introduction: More than one million breast augmentation procedures using silicone breast implants (SBI) have been performed worldwide. Adverse events of SBI include local complications such as pain, swelling, redness, infections, capsular contracture, implant rupture and gel-bleed. Furthermore, patients experience systemic symptoms such as chronic fatigue, arthralgias, myalgias, pyrexia, sicca, and cognitive dysfunction. These symptoms received different names such as autoimmune/inflammatory syndrome induced by adjuvants (ASIA) due to silicone incompatibility syndrome and breast implant illness (BII). Because of chronic immune activation, BII/ASIA, allergies, autoimmune diseases, immune deficiencies and finally lymphomas may develop in SBI patients.

Areas covered: Causality for SBI-related BII/ASIA is reviewed. To address the role of silicone implants in promoting causality, we utilized the Bradford-Hill criteria, with results highlighted in this article.

Expert opinion: We conclude that there is a causal association between SBIs and BII/ASIA. Using data derived from patients with BII/ASIA and from other medically implanted devices, there appears to be clear pathogenic relationship between SBI and BII/ASIA. Breast implants cause characteristic systemic reactions in certain women, leading to symptoms of sufficient severity to warrant device removal. The morbidity suffered is variable. SBI removal resolves the symptoms in most women and removal is the most effective treatment.

Source: Cohen Tervaert JW, Mohazab N, Redmond D, van Eeden C, Osman M. Breast implant illness: scientific evidence of its existence. Expert Rev Clin Immunol. 2021 Dec 9. doi: 10.1080/1744666X.2022.2010546. Epub ahead of print. PMID: 34882509. https://pubmed.ncbi.nlm.nih.gov/34882509/

The Role of Cytokines in Muscle Fatigue in Patients with Chronic Fatigue Syndrome (CFS)

Abstract:

CFS is characterized by profound levels of persistent/recurrent fatigue. It is proposed that chronic, low level inflammation may play a role in this fatigue. We recruited 100 untreated patients with CFS (average age 33±12) and 100 age and sex matched healthy controls (HCs). Serum levels of TNF-α were assessed using ELISA. Subjective fatigue was determined by questionnaire and muscle function tests were undertaken in subgroups in which maximal voluntary contraction (MVC), electrically stimulated muscle force generation and rate of fatigue were assessed in the quadriceps muscle.

Subjective fatigue was higher in patients with CFS compared with HCs. Preliminary analyses showed that serum TNF-α was undetectable in 97% of HCs, whereas 15% of patients with CFS had detectable (4.4+/-0.18pg/ml) serum TNF-α. MVC was significantly reduced in subjects with CFS compared with HCs. No difference was seen in stimulated muscle fatigue between groups.

This preliminary data suggests that a sub-group of patients with CFS may have low level inflammation and analyses are underway to further characterise other inflammatory markers in serum and muscle of these patients and to determine whether such changes could affect indices of muscle function or central fatigue.

Funded by MRC, BBSRC and the ME Association.

Source: Earl, K., Sakellariou, G., Owens, D., Sinclair, M., Fenech, M., Close, G., Lawton, C., Dye, L., Beadsworth, M. and McArdle, A. (2015), The Role of Cytokines in Muscle Fatigue in Patients with Chronic Fatigue Syndrome (CFS). The FASEB Journal, 29: 1055.34. https://doi.org/10.1096/fasebj.29.1_supplement.1055.34  https://faseb.onlinelibrary.wiley.com/doi/10.1096/fasebj.29.1_supplement.1055.34 (Full text)

Skeletal muscle alterations in patients with acute Covid-19 and post-acute sequelae of Covid-19

Abstract:

Background and methods: Skeletal muscle-related symptoms are common in both acute Covid-19 and Post-Acute Sequelae of Covid-19 (PASC). In this narrative review, we discuss cellular and molecular pathways that are affected, and consider these in regard to skeletal muscle involvement in other conditions, such as acute respiratory distress syndrome, critical illness myopathy and post-viral fatigue syndrome.
Results: Patients with severe Covid-19 and PASC suffer from skeletal muscle weakness and exercise intolerance. Histological sections present muscle fiber atrophy, metabolic alterations, and immune cell infiltration. Contributing factors to weakness and fatigue in patients with severe Covid-19 include systemic inflammation, disuse, hypoxemia, and malnutrition. These factors also contribute to post-ICU syndrome and ICU-acquired weakness, and likely explain a substantial part of Covid-19-acquired weakness. The skeletal muscle weakness and exercise intolerance associated with PASC are more obscure and different factors likely contribute. Direct SARS-CoV-2 viral infiltration into skeletal muscle or an aberrant immune system likely contribute. Similarities between skeletal muscle alterations in PASC and chronic fatigue syndrome deserve further study.
Conclusion: Both SARS-CoV-2 specific factors and generic consequences of acute disease likely underlie the observed skeletal muscle alterations in both acute Covid 19 and PASC.
Source: Soares, M., Eggelbusch, M., Naddaf, E., Gerrits, K., van der Schaaf, M., van den Borst, B., Wiersinga, W. J., et al. Skeletal muscle alterations in patients with acute Covid-19 and post-acute sequelae of Covid-19. Journal of Cachexia, Sarcopenia and Muscle. https://doi.org/10.17863/CAM.78509 https://www.repository.cam.ac.uk/handle/1810/331064

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/

Evaluation of Immune Dysregulation in an Austrian Patient Cohort Suffering from Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a severe multi-systemic disease characterized by debilitating fatigue that is not relieved by rest. The causes of the disease are still largely unexplained, and no causative treatment is currently available. Changes in the immune response are considered as fundamental in the development of ME/CFS. Thus, we aimed to evaluate the immunological profile of ME/CFS patients in a retrospective data analysis.

As part of the routine workup for ME/CFS patients, a differential blood count, leukocyte subtyping, and quantification of immunoglobulins and IgG subclasses, as well as a complement analysis, was performed. Out of 262 ME/CFS patients, 64.9% had a reduction or deficiency in at least one of the listed immune parameters. In contrast, 26.3% showed signs of immune activation or inflammation. A total of 17.6% of the ME/CFS patients had an unclassified antibody deficiency, with IgG3 and IgG4 subclass deficiencies as the most common phenotypes. Reduced MBL (mannose-binding lectin) levels were found in 32% of ME/CFS patients, and MBL deficiency in 7%.

In summary, the present results confirmed the relevance of immune dysfunction in ME/CFS patients underlining the involvement of a dysfunctional immune response in the disease. Thus, immune parameters are relevant disease biomarkers, which might lead to targeted therapeutic approaches in the future.

Source: Lutz L, Rohrhofer J, Zehetmayer S, Stingl M, Untersmayr E. Evaluation of Immune Dysregulation in an Austrian Patient Cohort Suffering from Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Biomolecules. 2021 Sep 14;11(9):1359. doi: 10.3390/biom11091359. PMID: 34572574. https://pubmed.ncbi.nlm.nih.gov/34572574/

Electroacupuncture improves cognitive function by inhibiting NF-κB activity in rats with chronic fatigue syndrome

Abstract:

Objective: To observe the effect of electroacupuncture (EA) on the expression of NF-κB p65 in hippocampus and the morphology of hippocampus in rats with chronic fatigue syndrome (CFS), so as to explore its mechanism in improving cognitive dysfunction of CFS.

Methods: Forty-eight SD rats were randomly divided into control, model, EA and inhibitor groups (n=12 in each group). The CFS model was established by multi-factor compound stress stimulation method. Rats of the EA group received EA (50 Hz, 1 mA) at “Baihui” (GV20), Emotional Area I and bilateral Sensory Area for 30 min, once daily for 15 days. For rats in the inhibitor group, pyrrolidine dithiocarbamate (100 mg·kg-1·d-1) was injected intraperitoneally, once a day for 15 days. Learning and memory ability was evaluated by Morris water maze test. HE staining was used to observe the morphology of hippocampus. Western blot was used to determine the expression level of NF-κB p65 in hippocampus.

Results: After mode-ling, the general status score was increased (P<0.01), the escape latency was prolonged(P<0.01), the times of crossing the platform was decreased(P<0.01), and the expression level of NF-κB p65 in hippocampus tissue was significantly increased (P<0.05) in the model group compared with the control group. Compared with the model group, the general status score was decreased (P<0.01), the escape latency was shortened(P<0.01), the times of crossing the platform was increased(P<0.01), and the expression level of NF-κB p65 in hippocampus tissue was significantly decreased (P<0.05) in the EA and inhibitor groups. HE staining showed that in the model group, the hippocampal nerve cells were arranged disorderly, the structure was loose, and the number of apoptotic bodies and inflammatory cells was significantly increased. The degree of tissue damage of the EA and inhibitor groups was milder than that of the model group.

Conclusion: EA can improve the cognitive function in CFS rats, which may be associated with its effect in inhibiting the expression of NF-κB and reducing the inflammation response in hippocampus.

Source: Feng CW, Qu YY, Sun ZR, Wang YL, Zhang P, Wang QY, Lin WJ, Zhang L, Yang TS. [Electroacupuncture improves cognitive function by inhibiting NF-κB activity in rats with chronic fatigue syndrome]. Zhen Ci Yan Jiu. 2021 Sep 25;46(9):775-81. Chinese. doi: 10.13702/j.1000-0607.200827. PMID: 34558244. https://pubmed.ncbi.nlm.nih.gov/34558244/ [Article in Chinese]

Inflammation-type dysbiosis of the oral microbiome associates with the duration of COVID-19 symptoms and long-COVID

Abstract:

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused the pandemic Coronavirus Disease 2019 (COVID-19) and now many face the burden of prolonged symptoms-long-lasting COVID-19 symptoms or “long-COVID”. Long-COVID is thought to be linked to immune dysregulation due to harmful inflammation, with the exact causes being unknown. Given the role of the microbiome in mediating inflammation, we aimed to examine the relationship between the oral microbiome and the duration of long-COVID symptoms. Tongue swabs were collected from patients presenting with symptoms concerning for COVID-19. Confirmed infections were followed until resolution of all symptoms.

Bacterial composition was determined by metagenomic sequencing. We used random forest modeling to identify microbiota and clinical covariates that associated with long-COVID symptoms. Of the patients followed, 63% (17/27) developed ongoing symptomatic COVID-19 and 37% (10/27) went on to long-COVID. Patients with prolonged symptoms had significantly higher abundances of microbiota that induce inflammation, such as members of the genera Prevotella and Veillonella. Of note are species that produce lipopolysaccharides and the similarity of long-COVID patients’ oral microbiome to those of patients with chronic fatigue syndrome. All together, we our findings suggest an association with the oral microbiome and long-COVID revealing the possibility that dysfunction of the oral microbiome may contribute to this draining disease.

Source: Haran JP, Bradley E, Zeamer AL, Cincotta L, Salive MC, Dutta P, Mutaawe S, Anya O, Meza-Segura M, Moormann AM, Ward DV, McCormick BA, Bucci V. Inflammation-type dysbiosis of the oral microbiome associates with the duration of COVID-19 symptoms and long-COVID. JCI Insight. 2021 Aug 17:152346. doi: 10.1172/jci.insight.152346. Epub ahead of print. PMID: 34403368. https://pubmed.ncbi.nlm.nih.gov/34403368/

Off label use of Aripiprazole shows promise as a treatment for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): a retrospective study of 101 patients treated with a low dose of Aripiprazole

Note: The ME Association does not recommend that anyone with ME/CFS attempt to obtain or to take this drug, even in small doses, until such time as more appropriate research can better determine safety and efficacy. Read their full statement here

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a chronic, debilitating illness of unknown etiology. An ME/CFS diagnosis is based solely on symptoms with case definitions made by expert consensus, including the Fukuda (1994), Canadian Consensus Criteria (CCC, 2003), International Consensus Criteria (ICC, 2011), and the Institute of Medicine (IOM, 2015) case criteria. According to the most recent IOM case definition, the core symptoms of ME/CFS include debilitating fatigue, unrefreshing sleep, post-exertional malaise, and either cognitive dysfunction or orthostatic intolerance [1]. Although the cause of the illness is unknown, a growing body of evidence suggests that ME/CFS involves inflammation of the brain. Up to 85% of patients with ME/CFS report symptoms of cognitive impairment also referred to as “brain fog,” which includes difficulty with memory, attention, and information processing. Additional evidence includes changes in inflammatory cytokines in both plasma and cerebrospinal fluid correlated with the severity of symptoms [2]. Other studies using positron emission tomography (PET) show evidence of activated microglia or astrocytes in various regions of the brain in patients with ME/CFS [3].

Source: Crosby, L.D., Kalanidhi, S., Bonilla, A. et al. Off label use of Aripiprazole shows promise as a treatment for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): a retrospective study of 101 patients treated with a low dose of Aripiprazole. J Transl Med 19, 50 (2021). https://doi.org/10.1186/s12967-021-02721-9 https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-021-02721-9 (Full text)

Undetected Jawbone Marrow Defects as Inflammatory and Degenerative Signaling Pathways: Chemokine RANTES/CCL5 as a Possible Link Between the Jawbone and Systemic Interactions?

Abstract:

Background: Cytokines, especially chemokines, are of increasing interest in immunology. This study characterizes the little-known phenomenon of “bone marrow defects of the jawbone” (BMDJ) with known overexpression of the chemokine RANTES/CCL5 (R/C).

Purpose: Our investigation clarifies why BMDJ and the intensity of local R/C overexpression are challenging to detect, as examined in patients with seven different systemic immunological diseases. Specifically, we investigate whether R/C overexpression is specific to certain disease groups or if it represents a type of signal disruption found in all systemic immunological diseases.

Patients and Methods: In a total of 301 patients, BMDJ was surgically repaired during clinical practice to reduce “silent inflammation” associated with the presence of jaw-related pathologies. In each case of BMDJ, bone density was measured preoperatively (in Hounsfield units [HU]), while R/C expression was measured postoperatively. Each of the 301 patients suffered from allergies, atypical facial and trigeminal pain, or were diagnosed with neurodegenerative diseases, tumors, rheumatism, chronic fatigue syndrome, or parasympathetic disorders.

Results: In all BMDJ cases, strongly negative HU values indicated decreased bone density or osteolysis. Consistently, all cases of BMDJ showed elevated R/C expression. These findings were consistently observed in every disease group.

Discussion: BMDJ was confirmed in all patients, as verified by the HU measurements and laboratory results related to R/C expression. The hypothesis that a specific subset of the seven disease groups could be distinguished either based on the increased presence of BMDJ and by the overexpression of R/C could not be confirmed. A brief literature review confirms the importance of R/C in the etiology of each of the seven disease groups.

Conclusion: In this research, the crucial role played by BMDJ and the chemokine R/C in inflammatory and immune diseases is discussed for seven groups of patients. Each specific immune disease can be influenced or propelled by BMDJ-derived R/C inflammatory signaling pathways.

Source: Lechner J, Schmidt M, von Baehr V, Schick F. Undetected Jawbone Marrow Defects as Inflammatory and Degenerative Signaling Pathways: Chemokine RANTES/CCL5 as a Possible Link Between the Jawbone and Systemic Interactions? J Inflamm Res. 2021 Apr 21;14:1603-1612. doi: 10.2147/JIR.S307635. PMID: 33911892; PMCID: PMC8071694.  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8071694/ (Full text)