Could the kynurenine pathway be the key missing piece of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) complex puzzle?

Abstract:

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a complex and debilitating disease with a substantial social and economic impact on individuals and their community. Despite its importance and deteriorating impact, progresses in diagnosis and treatment of ME/CFS is limited. This is due to the unclear pathophysiology of the disease and consequently lack of prognostic biomarkers.

To investigate pathophysiology of ME/CFS, several potential pathologic hallmarks have been investigated; however, these studies have failed to report a consistent result. These failures in introducing the underlying reason for ME/CFS have stimulated considering other possible contributing mechanisms such as tryptophan (TRP) metabolism and in particular kynurenine pathway (KP).

KP plays a central role in cellular energy production through the production of nicotinamide adenine dinucleotide (NADH). In addition, this pathway has been shown to mediate immune response and neuroinflammation through its metabolites. This review, we will discuss the pathology and management of ME/CFS and provide evidence pertaining KP abnormalities and symptoms that are classic characteristics of ME/CFS. Targeting the KP regulation may provide innovative approaches to the management of ME/CFS.

Source: Kavyani B, Lidbury BA, Schloeffel R, Fisher PR, Missailidis D, Annesley SJ, Dehhaghi M, Heng B, Guillemin GJ. Could the kynurenine pathway be the key missing piece of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) complex puzzle? Cell Mol Life Sci. 2022 Jul 11;79(8):412. doi: 10.1007/s00018-022-04380-5. PMID: 35821534. https://link.springer.com/article/10.1007/s00018-022-04380-5  (Full text)

Evidence-Based Care for People with Chronic Fatigue Syndrome and Myalgic Encephalomyelitis

Letter to the Editor:

Sharpe et al. suggest that “the available evidence from randomized trials supports the use of the rehabilitative therapies of CBT and GET for patients with CFS/ME”.1 However, the current NICE guideline on the diagnosis and management of ME/CFS (which replaced the out-of-date guideline CG53 cited by Sharpe et al.) recommends that CBT and GET should not be prescribed as treatments for ME/CFS, due to the lack of evidence of efficacy and concerns about safety.2 As part of the process of updating its guidance, NICE reviewed all the relevant evidence from trials of these therapies. It concluded that none was better than low quality and that most was very low quality.3

It is notable that such therapies were first promoted and prescribed for ME/CFS before any clinical trials had been conducted to assess their efficacy or safety. In 1989, Wessely et al. acknowledged that it “may be correct in some cases” that physical and mental exertion should be avoided by people with ME/CFS, but they went on to recommend behavioural and cognitive therapies which encouraged patients to ignore their symptoms and gradually increase exercise, as there was “as yet no way” to identify the cases where such approaches may be harmful. Furthermore, the authors suggested that “it is reasonable to expect a patient to cooperate with treatment before being labelled as chronically disabled” for the purposes of receiving sickness benefits.4

Sharpe et al. acknowledge that since then CBT and GET have been “the most researched approaches” to treating what they refer to as CFS/ME. However, despite this, they conclude that “more research is needed into these approaches” and that “it would be a disservice to our patients to tell them we have nothing to offer them”.

It is deeply regrettable that, as NICE has concluded, there are currently no proven effective treatments for ME/CFS. However, it would be a far greater disservice to patients to prescribe ineffective and potentially harmful therapies than to tell them the truth. Given the history of how these therapies have been promoted, prescribed and researched, it is perhaps not surprising if some are reluctant to accept the evidence that they do not work and may be harmful. However, as Wilshire et al. concluded in their 2018 reanalysis of the PACE trial data: “The time has come to look elsewhere for effective treatments.”5

Read this article HERE.

Source: Saunders R. Evidence-Based Care for People with Chronic Fatigue Syndrome and Myalgic Encephalomyelitis. J Gen Intern Med. 2022 Jul 5. doi: 10.1007/s11606-022-07715-x. Epub ahead of print. PMID: 35790668. https://link.springer.com/article/10.1007/s11606-022-07715-x (Full text)

Challenges of memory enhancers

Abstract:

40 per cent of people over the age of 65 experience some form of memory loss, called as the age related memory impairment. This might be due to hormone and proteins (Growth factors) which repair the brain cells decline with age. Certain conditions such as age, stress, disease and excessive emotional response may lead to loss of memory, loss of learning ability and altered mood and behaviour. These conditions may be treated by using nootropic agents which can help to improve learning abilities and memory.

Source: Chaudhry, Sunil. Challenges of memory enhancers. Annals of Geriatric Education and Medical Sciences; 2020/08/22. https://www.agems.in/article-details/11990 (Full text)

Treatments of chronic fatigue syndrome and its debilitating comorbidities: a 12-year population-based study

Abstract:

Background: This study aims to provide 12-year nationwide epidemiology data to investigate the epidemiology and comorbidities of and therapeutic options for chronic fatigue syndrome (CFS) by analyzing the National Health Insurance Research Database.

Methods: 6306 patients identified as having CFS during the 2000-2012 period and 6306 controls (with similar distributions of age and sex) were analyzed.

Result: The patients with CFS were predominantly female and aged 35-64 years in Taiwan and presented a higher proportion of depression, anxiety disorder, insomnia, Crohn’s disease, ulcerative colitis, renal disease, type 2 diabetes, gout, dyslipidemia, rheumatoid arthritis, Sjogren syndrome, and herpes zoster. The use of selective serotonin receptor inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), Serotonin antagonist and reuptake inhibitors (SARIs), Tricyclic antidepressants (TCAs), benzodiazepine (BZD), Norepinephrine-dopamine reuptake inhibitors (NDRIs), muscle relaxants, analgesic drugs, psychotherapies, and exercise therapies was prescribed significantly more frequently in the CFS cohort than in the control group.

Conclusion: This large national study shared the mainstream therapies of CFS in Taiwan, we noticed these treatments reported effective to relieve symptoms in previous studies. Furthermore, our findings indicate that clinicians should have a heightened awareness of the comorbidities of CFS, especially in psychiatric problems.

Source: Leong KH, Yip HT, Kuo CF, Tsai SY. Treatments of chronic fatigue syndrome and its debilitating comorbidities: a 12-year population-based study. J Transl Med. 2022 Jun 11;20(1):268. doi: 10.1186/s12967-022-03461-0. PMID: 35690765. https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-022-03461-0  (Full study)

Neurovascular Dysregulation and Acute Exercise Intolerance in ME/CFS: A Randomized, Placebo-Controlled Trial of Pyridostigmine

Abstract:

Background: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is characterized by intractable fatigue, post-exertional malaise, and orthostatic intolerance, but its pathophysiology is poorly understood. Pharmacologic cholinergic stimulation was used to test the hypothesis that neurovascular dysregulation underlies exercise intolerance in ME/CFS.

Research Question: Does neurovascular dysregulation contribute to exercise intolerance in ME/CFS and can its treatment improve exercise capacity?

Methods: Forty-five subjects with ME/CFS were enrolled in a single-center, randomized, double-blind, placebo-controlled trial. Subjects were assigned in a 1:1 ratio to receive a 60 mg dose of oral pyridostigmine or placebo after an invasive cardiopulmonary exercise test (iCPET). A second iCPET was performed 50 minutes later. The primary end point was the difference in peak exercise oxygen uptake (VO2). Secondary end points included exercise pulmonary and systemic hemodynamics and gas exchange.

Results: Twenty-three subjects were assigned to pyridostigmine and 22 to placebo. The peak VO2 increased after pyridostigmine but decreased after placebo (13.3 ± 13.4 mL/min vs. -40.2 ± 21.3 mL/min, P<0.05). The treatment effect of pyridostigmine was 53.6 mL/min (95% CI, -105.2 to -2.0). Peak versus rest VO2 (25.9 ± 15.3 mL/min vs. -60.8 ± 25.6 mL/min, P<0.01), cardiac output (-0.2 ± 0.6 L/min vs. -1.9 ± 0.6 L/min, P<0.05), and RAP (1.0 ± 0.5 mm Hg vs. -0.6 ± 0.5 mm Hg, P<0.05) were greater in the pyridostigmine group compared to placebo.

Interpretation: Pyridostigmine improves peak VO2 in ME/CFS by increasing cardiac output and right ventricular filling pressures. Worsening peak exercise VO2, Qc, and RAP after placebo may signal the onset of post-exertional malaise. We suggest treatable neurovascular dysregulation underlies acute exercise intolerance in ME/CFS.

Abbreviations List: Ca-vO2 (arterial-venous oxygen content difference), iCPET (Invasive cardiopulmonary exercise test), MAP (Mean arterial pressure), mPAP (Mean pulmonary artery pressure), ME/CFS (Myalgic encephalomyelitis/chronic fatigue syndrome), PASC (Post-acute sequelae of SARS-CoV-2 infection), PAWP (Pulmonary arterial wedge pressure), POTS (Postural orthostatic tachycardia syndrome), Qc (Cardiac output), RAP (Right atrial pressure), SE (Standard error), SFN (Small fiber neuropathy), VE/VCO2 (Ventilatory efficiency), VO2 (Oxygen uptake)

Source: Phillip Joseph, MD, Rosa Pari, MD, Sarah Miller, BS, Arabella Warren, BS, Mary Catherine Stovall, BS, Johanna Squires, MSc, Chia-Jung Chang, PhD, Wenzhong Xiao, PhD, Aaron B. Waxman, MD, PhD, David M. Systrom, MD. Neurovascular Dysregulation and Acute Exercise Intolerance in ME/CFS: A Randomized, Placebo-Controlled Trial of Pyridostigmine. Chest, Published: May 05, 2022. DOI: https://doi.org/10.1016/j.chest.2022.04.146

Acute effect of pyridostigmine in exertional intolerance in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): A randomized placebo-controlled clinical trial

Rationale: One third of patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) have evidence of small fiber neuropathy (SFN). Neurovascular dysregulation during upright exercise may be associated with impaired venoconstriction resulting in low biventricular filling pressures and impaired arteriolar constriction resulting in a mismatch between perfusion and skeletal muscle metabolism. We hypothesize that pyridostigmine, a reversible acetylcholinesterase inhibitor, may improve vascular regulation and exercise tolerance in ME/CFS by increasing sympathetic outflow.

Methods: 45 subjects (39 women, 6 men) with ME/CFS were assessed. A baseline invasive cardiopulmonary exercise test (iCPET) was performed to confirm presence of low peak exercise RAP (<6.5mmHg). Eligible subjects were blindly administered placebo (n=22) or 60mg pyridostigmine (n=23) at a 1:1 ratio. A second iCPET was performed following a 50 minute combined rest and dosing period. Serial iCPET results were compared to assess changes in oxygen uptake at peak exercise (VO2 max). Secondary outcomes included subject ventilatory efficiency (VE/VCO2), peak hemodynamic response (RAP, PCWP, SV, Qt), systemic gas exchange (Ca-vO2/Hgb), and subjective reporting of dyspnea and fatigue. Results: 39 subjects (all women) were considered in data analysis. There was a significant increase in VO2 max between iCPET 1 and iCPET 2 in the treatment group when compared with the placebo group (p = 0.043).

There was a significant decrease in the placebo group and a significant increase in the treatment group in VO2 (p = 0.008), Qt (p = 0.039), and RAP (p = 0.045) when comparing iCPET 1 peak – rest and iCPET 2 peak – rest between groups. There were no significant differences in peak arteriovenous oxygen content difference (Ca-vO2/Hgb). 38% of subjects had objective evidence of SFN with no statistically significant difference between groups.

Conclusion: Using pyridostigmine as an investigative tool, this study suggests that neurovascular dysregulation underlies acute exercise intolerance in ME/CFS. Additionally, we have new evidence that worsening vascular dysregulation results from prior exercise, which sheds insight into the post exertional malaise that is a hallmark of this syndrome.

Source: M. Stovall, P. Joseph, R. Pari, A. Warren, S. Miller, J. Squires, W. Xiao, A.B. Waxman, D.M. Systrom. Acute effect of pyridostigmine in exertional intolerance in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): A randomized placebo-controlled clinical trial. American Journal of Respiratory and Clinical Care Medicine, Vol 205, p A2063, May 2022. https://www.atsjournals.org/doi/pdf/10.1164/ajrccm-conference.2022.205.1_MeetingAbstracts.A2063

Molecular Hydrogen as a Medical Gas for the Treatment of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Possible Efficacy Based on a Literature Review

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a disorder that is characterized by fatigue that persists for more than 6 months, weakness, sleep disturbances, and cognitive dysfunction.

There are multiple possible etiologies for ME/CFS, among which mitochondrial dysfunction plays a major role in abnormal energy metabolism.

The potential of many substances for the treatment of ME/CFS has been examined; however, satisfactory outcomes have not yet been achieved. The development of new substances for curative, not symptomatic, treatments is desired.

Molecular hydrogen (H2) ameliorates mitochondrial dysfunction by scavenging hydroxyl radicals, the most potent oxidant among reactive oxygen species.

Animal experiments and clinical trials reported that H2 exerted ameliorative effects on acute and chronic fatigue. Therefore, we conducted a literature review on the mechanism by which H2 improves acute and chronic fatigue in animals and healthy people and showed that the attenuation of mitochondrial dysfunction by H2 may be involved in the ameliorative effects.

Although further clinical trials are needed to determine the efficacy and mechanism of H2 gas in ME/CFS, our literature review suggested that H2 gas may be an effective medical gas for the treatment of ME/CFS.

Source: Shin-ichi Hirano, Yusuke Ichikawa, Bunpei Sato, Yoshiyasu Takefuji and Fumitake Satoh. Molecular Hydrogen as a Medical Gas for the Treatment of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Possible Efficacy Based on a Literature Review. Front. Neurol., 11 April 2022  https://doi.org/10.3389/fneur.2022.841310 (Full text)

Individualizing medical treatment in chronic fatigue syndrome/ myalgic encephalomyelitis: Evidence for effective medications and possible relevance to “Long-Hauler Syndrome” in Covid-19 affected patients

Abstract:

Large controlled studies of Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME) have shown no effective medical treatment for this disorder. There are individual patients, however, with dramatic responses to some medications.

We report two patients with clear responses to rintatolimod and galantamine characterized by rapid reduction of symptoms on starting treatment and return of symptoms on withdrawal.

As in cancer, CFS/ME is a heterogeneous disorder but unlike most cancers, such as melanoma, breast cancer, and B-cell lymphoma, CFS/ME has no known biological marker that can distinguish between subtypes.

We suggest an approach to medical treatment of CFS/ME that could be utilized by primary caregivers that offer the possibility of more rapid and complete recovery from this debilitating disorder.

Current studies indicate that prolonged symptomatic recovery from infection with Covid-19 (“long hauler syndrome” or PASC, for post-acute sequelae of Covid-19) represents a severe form of CFS/ME and thus may also be amenable to personalized medicine with specific medications.

Source: Levine PH, Ajmera KM, Bjorke B, Peterson D. Individualizing medical treatment in chronic fatigue syndrome/myalgic
encephalomyelitis: Evidence for effective medications and possible relevance to “Long-Hauler Syndrome” in Covid-19 affected
patients. J Clin Images Med Case Rep. 2022; 3(1): 1681. https://jcimcr.org/pdfs/JCIMCR-v3-1681.pdf (Full text)

 

Oral Minocycline Challenge as a Potential First-Line Therapy for Myalgic Encephalomyelitis and Long Covid-19 Syndrome

Abstract:

Chronic fatigue syndrome characterized by severe disabling fatigue, prolonged post-exertional malaise, and unrefreshing sleep markedly reduces the activities of daily living and impairs the quality of life.

Central nervous system dysfunction associated with myalgic encephalomyelitis (ME) has been postulated as the main cause of chronic fatigue syndrome.

Recently, oral minocycline therapy has been reported to exert favorable therapeutic effects in some patients with ME, especially in the initial stage of the disease, although many patients discontinued treatment in the first few days because of acute adverse effects such as nausea and/or dizziness.

Minocycline appeared to exert a variety of biologic actions against neural inflammation that are independent of their anti-microbial activity, including anti-inflammatory, immunomodulatory, and neuroprotective effects.

In recent years, it has been noted that COVID-19 disease may cause persistent signs and symptoms described as post-COVID syndrome or long COVID, in which the clinical presentation is remarkably similar to those seen in patients with ME.

A wide range of infectious agents have been suggested to trigger the development of ME, and one of such pathogens may be the COVID-19 virus.

Recently, I had a valuable experience of a 22-year-old female patient with a 14-month duration of long COVID who completely recovered from ME-like symptoms after treatment with minocycline. This case suggests that oral minocycline could be an effective first-line therapy for long COVID-19, although a large scale of trial is obviously needed to justify the therapy.

Source: Miwa K. Oral Minocycline Challenge as a Potential First-Line Therapy for Myalgic Encephalomyelitis and Long Covid-19 Syndrome. Ann Clin Med Case Rep. 2022; V8(7): 1-4 https://acmcasereport.com/wp-content/uploads/2022/01/ACMCR-v8-1710.pdf  (Full article available as PDF file)

A comparative study of valaciclovir, valganciclovir, and artesunate efficacy in reactivated HHV-6 and HHV-7 infections associated with chronic fatigue syndrome/myalgic encephalomyelitis

Abstract:

The study aimed to compare the efficacy of valaciclovir, valganciclovir, and artesunate in treating chronic reactivated HHV-6 and HHV-7 associated with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). From 255 patients with reactivated HHV-6 and HHV-7 infections (blood leukocyte PCR) in 192 cases, valaciclovir, valganciclovir, or artesunate were administered at a dose of 3,000, 900, and 100 mg per day, respectively, for 3 months (study group). The control group consisted of similar 63 ME/CFS patients not taking any antiviral drugs. The significance of differences was evaluated by Student’s T-test and the non-parametric criterion – the number of Z-signs. Negative PCR results in HHV6 and HHV-7 treated with valaciclovir was achieved in 26% and 23% (first), 34%, and 28% (second), 37% and 34% of cases (third month), respectively (p<0.05; Z<Z0.05 ). The same results with valganciclovir were obtained in 35% and 33% (first), 44% and 39% (second), 48% and 45% (third month), but with artesunate – in 44% and 41% (first), 57% and 53% (second), 68% and 63% of cases (third month), respectively (p<0.05; Z<Z0.05 ). Artesunate is more effective than valganciclovir and valacyclovir in ME/CFS patients with reactivated HHV-6 and HHV-7 infections.

Source: Maltsev D. A comparative study of valaciclovir, valganciclovir, and artesunate efficacy in reactivated HHV-6 and HHV-7 infections associated with chronic fatigue syndrome/myalgic encephalomyelitis. Microbiol Immunol. 2022 Jan 31. doi: 10.1111/1348-0421.12966. Epub ahead of print. PMID: 35102619. https://pubmed.ncbi.nlm.nih.gov/35102619/