Tag: review

The significance of oxidative stress in the pathophysiology of Long COVID and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)

Abstract:

Long COVID is now well accepted as an ongoing post-viral syndrome resulting from infection of a single virus, the pandemic SARS-CoV-2. It mirrors the post-viral fatigue syndrome, Myalgic Encephalomyelitis/ Chronic Fatigue Syndrome, a global debilitating illness arising mainly from sporadic geographically-specific viral outbreaks, and from community endemic infections, but also from other stressors. Core symptoms of both syndromes are post-exertional malaise (a worsening of symptoms following mental or physical activity), pervasive fatigue, cognitive dysfunction (brain fog), and sleep disturbance. Long COVID patients frequently also suffer from shortness of breath, relating to the lung involvement of the SARS-CoV-2 virus.

There is no universally accepted pathophysiology, or recognized biomarkers yet for Long COVID or indeed for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Clinical case definitions with very similar characteristics for each have been defined. Chronic inflammation, immune dysfunction, and disrupted energy production in the peripheral system has been confirmed in Long COVID and has been well documented in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Neuroinflammation occurs in the brain in Myalgic Encephalomyelitis/ Chronic Fatigue Syndrome as shown from a small number of positron emission tomography and magnetic resonance spectroscopy studies, and has now been demonstrated for Long COVID. Oxidative stress, an increase in reactive oxygen and reactive nitrogen species, and free radicals, has long been suggested as a potential cause for many of the symptoms seen in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome, resulting from both activation of the brain’s immune system and dysregulation of mitochondrial function throughout the body. The brain as a high producer of energy may be particularly susceptible to oxidative stress. It has been shown in peripheral immune cells that the balanced production of proteins involved in regulation of the reactive oxygen species in mitochondria is disturbed in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Fluctuations in the chronic low level neuroinflammation during the ongoing course of Long COVID as well as Myalgic Encephalomyelitis/Chronic Fatigue Syndrome have been proposed to cause the characteristic severe relapses in patients.

This review explores oxidative stress as a likely significant contributor to the pathophysiology of Long COVID and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome, and the mechanisms by which oxidative stress could cause the symptoms seen in both syndromes. Treatments that could mitigate oxidative stress and thereby lessen the debilitating symptoms to improve the life of patients are discussed.

Source: WALKER, Max Oliver Mackay et al. The significance of oxidative stress in the pathophysiology of Long COVID and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). Medical Research Archives, [S.l.], v. 10, n. 9, sep. 2022. ISSN 2375-1924. Available at: <https://esmed.org/MRA/mra/article/view/3050>. Date accessed: 09 oct. 2022. doi: https://doi.org/10.18103/mra.v10i9.3050.

Lactoferrin as Possible Treatment for Chronic Gastrointestinal Symptoms in Children with Long COVID: Case Series and Literature Review

Abstract:

Long COVID is an emergent, heterogeneous, and multisystemic condition with an increasingly important impact also on the pediatric population. Among long COVID symptoms, patients can experience chronic gastrointestinal symptoms such as abdominal pain, constipation, diarrhea, vomiting, nausea, and dysphagia.
Although there is no standard, agreed, and optimal diagnostic approach or treatment of long COVID in children, recently compounds containing multiple micronutrients and lactoferrin have been proposed as a possible treatment strategy, due to the long-standing experience gained from other gastrointestinal conditions. In particular, lactoferrin is a pleiotropic glycoprotein with antioxidant, anti-inflammatory, antithrombotic, and immunomodulatory activities. Moreover, it seems to have several physiological functions to protect the gastrointestinal tract.
In this regard, we described the resolution of symptoms after the start of therapy with high doses of oral lactoferrin in two patients referred to our post-COVID pediatric unit due to chronic gastrointestinal symptoms after SARS-CoV-2 infection.
Source: Morello R, De Rose C, Cardinali S, Valentini P, Buonsenso D. Lactoferrin as Possible Treatment for Chronic Gastrointestinal Symptoms in Children with Long COVID: Case Series and Literature Review. Children. 2022; 9(10):1446. https://doi.org/10.3390/children9101446 (Full text)

Polyphenols as possible alternative agents in chronic fatigue: a review

Abstract:

Chronic fatigue syndrome (CFS) is a pathological state of extreme tiredness that lasts more than six months and may possess an impact on the social, emotional, or occupational functioning of an individual. CFS is characterized by profound disabling fatigue associated with infectious, rheumatological, and neurological symptoms.

The current pharmacological treatment for CFS does not offer a complete cure for the disease, and none of the available treatments show promising results.

The exact mechanism of the pathogenesis of the disease is still unknown, with current suggestions indicating the overlapping roles of the immune system, central nervous system, and neuroendocrine system.

However, the pathological mechanism revolves around inflammatory and oxidative stress markers.

Polyphenols are the most abundant secondary metabolites of plant origin, with potent antioxidant and anti-inflammatory effects, and can exert protective activity against a whole range of disorders.

The current review is aimed at highlighting the emerging role of polyphenols in CFS from both preclinical and clinical studies. Numerous agents of this class have shown promising results in different in vitro and in vivo models of chronic fatigue/CFS, predominantly by counteracting oxidative stress and the inflammatory cascade.

The clinical data in this regard is still very limited and needs expanding through randomized, placebo-controlled studies to draw final conclusions on whether polyphenols may be a class of clinically effective nutraceuticals in patients with CFS.

Source: Ullah, H., Khan, A., Riccioni, C. et al. Polyphenols as possible alternative agents in chronic fatigue: a review. Phytochem Rev (2022). https://doi.org/10.1007/s11101-022-09838-9 (Full text)

Post-acute COVID syndrome (long COVID): What should radiographers know and the potential impact for imaging services

Abstract:

Objectives: The COVID-19 pandemic caused an unprecedented health crisis resulting in over 6 million deaths worldwide, a figure, which continues to grow. In addition to the excess mortality, there are individuals who recovered from the acute stages, but suffered long-term changes in their health post COVID-19, commonly referred to as long COVID. It is estimated there are currently 1.8 million long COVID sufferers by May 2022 in the UK alone. The aim of this narrative literature review is to explore the signs, symptoms and diagnosis of long COVID and the potential impact on imaging services.

Key findings: Long COVID is estimated to occur in 9.5% of those with two doses of vaccination and 14.6% if those with a single dose or no vaccination. Long COVID is defined by ongoing symptoms lasting for 12 or more weeks post acute infection. Symptoms are associated with reductions in the quality of daily life and may involve multisystem manifestations or present as a single symptom.

Conclusion: The full impact of long COVID on imaging services is yet to be realised, but there is likely to be significant increased demand for imaging, particularly in CT for the assessment of lung disease. Educators will need to include aspects related to long COVID pathophysiology and imaging presentations in curricula, underpinned by the rapidly evolving evidence base.

Implications for practice: Symptoms relating to long COVID are likely to become a common reason for imaging, with a particular burden on Computed Tomography services. Planning, education and updating protocols in line with a rapidly emerging evidence base is going to be essential.

Source: Alghamdi F, Owen R, Ashton REM, Obotiba AD, Meertens RM, Hyde E, Faghy MA, Knapp KM, Rogers P, Strain WD. Post-acute COVID syndrome (long COVID): What should radiographers know and the potential impact for imaging services. Radiography (Lond). 2022 Sep 12:S1078-8174(22)00119-5. doi: 10.1016/j.radi.2022.08.009. Epub ahead of print. PMID: 36109264; PMCID: PMC9468096. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9468096/ (Full text)

What we already know about the Post-COVID-19 Syndrome: A narrative review

Abstract:

As an increasingly number of patients recover from the acute COVID-19 disease, it has been observed that many face long lasting symptoms, referred as the Post-COVID-19 Syndrome. This article covers the most common signs and symptoms of this syndrome, its general aspects, and important complementary exams related to the disease. The manuscript is a narrative review, gathering new evidence published about the topic.

The most common symptoms of the Post-COVID-19 Syndrome are chronic fatigue, breathlessness, depression or anxiety, pain, cough and alopecia, and many of them are still present 6 months after hospital discharge from the acute disease, depending on the gravity of the illness. It is important for patients to maintain medical follow-up to access severity of the symptoms and choose whether further investigation is necessary. There are some treatments available to some minimize the long-lasting burden of the syndrome, and the physician should access the need for treatment with the patient.

As a new disease, there is a lot of new evidence being produced rapidly, but no up-to-date protocol has already been published. Even with the vaccinations campaigns, the burden of the pandemic is yet out of sight, as it still killing thousands daily, and those who have recovered from the acute COVID-19 illness can present chronic symptoms. Therefore, we recommend health professionals to continuously up-to-date themselves, as new information is added to make better clinical decisions.

Source: RESENDE, M. D. de .; RESENDE, G. D. de .; RIQUIERI, L. N. .; SANTOS, A. F. A. dos .; CASTRO, A. C. A. de .; ROCHA, M. da C. . What we already know about the Post-COVID-19 Syndrome: A narrative review. Research, Society and Development, [S. l.], v. 11, n. 12, p. e108111234143, 2022. DOI: 10.33448/rsd-v11i12.34143. https://rsdjournal.org/index.php/rsd/article/view/34143

Current knowledge about Chronic fatigue syndrome / myalgic encephalomyelitis (CFS/ME) causes – summary

Abstract:

Chronic Fatigue Syndrome (CFE) is a severe and disabling disease whose etiology has not yet been elucidated. This implies the lack of a specific biomarker for the diagnosis of PE, and no causal treatment.

There are a number of diagnostic criteria that facilitate the diagnosis of PE, but it is still a diagnosis with exclusion. This chapter reviews the scientific literature systematically, summarizing the available knowledge about the probable etiology of Chronic Fatigue Syndrome.

The current topic of the influence of SARS-Cov-2 virus infection on the development of symptoms of IPC was also taken into account in particular.

A clear explanation of the etiology of PE is necessary for the further development of scientific knowledge about the Chronic Fatigue Syndrome.

Source: PRYLIŃSKA-JAŚKOWIAK, Monika & KOŻUCHOWSKI, Marcin. Current knowledge about Chronic fatigue syndrome / myalgic encephalomyelitis (CFS/ME) causes – summary. Journal of Education, Health and Sport [online]. 13 September 2022, T. 12, nr 9, s. 712–719. [accessed 26.9.2022]. DOI 10.12775/JEHS.2022.12.09.084.  https://apcz.umk.pl/JEHS/article/view/39954 https://apcz.umk.pl/JEHS/article/view/39954/33214 (Full text)

The potential role of ischaemia-reperfusion injury in chronic, relapsing diseases such as rheumatoid arthritis, Long COVID, and ME/CFS: evidence, mechanisms, and therapeutic implications

Abstract:

Ischaemia-reperfusion (I-R) injury, initiated via bursts of reactive oxygen species produced during the reoxygenation phase following hypoxia, is well known in a variety of acute circumstances. We argue here that I-R injury also underpins elements of the pathology of a variety of chronic, inflammatory diseases, including rheumatoid arthritis, ME/CFS and, our chief focus and most proximally, Long COVID.

Ischaemia may be initiated via fibrin amyloid microclot blockage of capillaries, for instance as exercise is started; reperfusion is a necessary corollary when it finishes. We rehearse the mechanistic evidence for these occurrences here, in terms of their manifestation as oxidative stress, hyperinflammation, mast cell activation, the production of marker metabolites and related activities.

Such microclot-based phenomena can explain both the breathlessness/fatigue and the post-exertional malaise that may be observed in these conditions, as well as many other observables. The recognition of these processes implies, mechanistically, that therapeutic benefit is potentially to be had from antioxidants, from anti-inflammatories, from iron chelators, and via suitable, safe fibrinolytics, and/or anti-clotting agents. We review the considerable existing evidence that is consistent with this, and with the biochemical mechanisms involved.

Source: Kell DB, Pretorius E. The potential role of ischaemia-reperfusion injury in chronic, relapsing diseases such as rheumatoid arthritis, Long COVID, and ME/CFS: evidence, mechanisms, and therapeutic implications. Biochem J. 2022 Aug 31;479(16):1653-1708. doi: 10.1042/BCJ20220154. PMID: 36043493. https://portlandpress.com/biochemj/article/479/16/1653/231696/The-potential-role-of-ischaemia-reperfusion-injury (Full text)

Cardiac impairments in postacute COVID-19 with sustained symptoms: A review of the literature and proof of concept

Abstract:

Although acute COVID-19 is known to cause cardiac damage in some cases, there is still much to learn about the duration and relative permanence of the damage that may occur. Long COVID is a condition that can occur when COVID-19 symptoms remain in the postviral acute period. Varying accounts of long COVID have been described across the literature, however, cardiac impairments are sustained in many individuals and cardiovascular assessment is now considered to be an expected follow-up examination.

The purpose of this review and proof of concept is to summarize the current research related to the assessment of cardiac function, including echocardiography and blood biomarker data, during the follow-up period in patients who recovered from COVID-19. Following a literature review, it was found that right ventricular dysfunction along with global longitudinal strain and diastolic dysfunction are common findings.

Finally, more severe acute myocardial injury during the index hospitalization appears to exacerbate cardiac function. The available literature implies that cardiac function must be monitored in patients recovered from COVID-19 who remain symptomatic and that the impairments and severity vary from person-to-person.

The proof-of-concept analysis of patients with cardiac disease and respiratory disease in comparison to those with sustained symptoms from COVID-19 suggests elevated systolic time interval in those with sustained symptoms from COVID-19, thus reducing heart performance indices. Future research must consider the details of cardiac complications during the acute infection period and relate this to the cardiac function in patients with long COVID during mid- and long-term follow-up.

Source: Singh J, Bhagaloo L, Sy E, Lavoie AJ, Dehghani P, Bardutz HA, Mang CS, Buttigieg J, Neary JP. Cardiac impairments in postacute COVID-19 with sustained symptoms: A review of the literature and proof of concept. Physiol Rep. 2022 Aug;10(16):e15430. doi: 10.14814/phy2.15430. PMID: 35993433; PMCID: PMC9393908.  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9393908/ (Full text)

NeuroCOVID-19: a critical review

Abstract:

Background: The COVID-19 pandemic has challenged neurologists since its early days. Neurology consultation services were then overloaded by emergency department and intensive-care patients with acute neurological syndromes. These complications are better explained today, but the growing number of patients with reported longstanding neurological symptoms constitute an emerging, complex, and still poorly understood phenomenon.

Objective: This review summarizes data on relevant neurological manifestations of acute SARS-CoV-2 infection and lasting post-infectious disease, also known as Long COVID. The complex history of Long COVID is examined to illustrate the upsides and challenges imposed by the active participation of patient communities in the production of medical knowledge.

Methods: Narrative review.

Results: Infection with the severe acute respiratory syndrome coronavirus 2 is associated with encephalopathy/delirium, cerebrovascular disease, headache, and peripheral nervous system involvement. Long COVID is a living concept jointly defined by patient communities, physicians and scientists, including neurologists.

Conclusion: Co-production of Long COVID knowledge between scientists and patients has initiated an era of patient-led research and evidence-based activism that acts as a two-edged sword – putting patient’s suffering in the spotlight, but with a tradeoff in methodological consistency.

Source: Guedes BF. NeuroCOVID-19: a critical review. Arq Neuropsiquiatr. 2022 May;80(5 Suppl 1):281-289. doi: 10.1590/0004-282X-ANP-2022-S136. PMID: 35976326. https://www.scielo.br/j/anp/a/v6c3Xcvq4PkkD3HvKtT7DJN/?lang=en  (Full tex)

Myalgic encephalomyelitis/chronic fatigue syndrome and pregnancy: A mixed-methods systematic review

Abstract:

Background Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a fluctuating complex condition. More common in women than men, it tends to develop between mid-20s and mid-40s, including the main childbearing age (15–45 years). There are currently no systematic reviews summarising evidence relating to ME/CFS and pregnancy. The lack of quality assessed, and systematic summary evidence makes it harder for people with ME/CFS to make informed decisions about pregnancy, and harder for health care professionals to offer evidence-based care. This mixed methods systematic review aims to examine and summarise existing evidence relating to ME/CFS and pregnancy, both in relation to pregnancy outcomes and experiences of pregnancy but also the effect of pregnancy on ME/CFS severity and symptoms.

Methods This review followed a convergent segregated design. Seven electronic databases, relevant grey literature, reference lists of relevant reviews, and reference lists and citations of all included studies, were searched. Where necessary, authors were contacted for additional information. Studies of any design published in English, reporting on ME/CFS and pregnancy/postpartum (up to two years), risk of pregnancy outcomes with ME/CFS, or experiences during pregnancy for mother, partner or health and social care professionals following pregnancy with ME/CFS were included. Three researchers performed screening, data extraction and quality assessments independently. Qualitative and quantitative literature was analysed separately using thematic and descriptive syntheses, respectively (meta-analysis was not appropriate). Findings were integrated through configuration.

Results Searches identified n=2,789 studies, n=10 met our inclusion criteria. There were five quantitative studies, two qualitative studies and three pieces of grey literature. Preliminary results suggest that evidence is conflicting. In the qualitative literature, one study suggested one participant thought pregnancy improved ME/CFS symptoms while the other noted a participant commented that ME/CFS may have adversely affected her pregnancy. Of the four quantitative studies that reported on ME severity during pregnancy, two suggested pregnancy negatively impacted on ME/CFS, one study found most women had no change in ME/CFS symptoms during pregnancy, and one found ME/CFS improved during pregnancy. Only one study reported on pregnancy outcomes, finding a higher rate of spontaneous abortions, and increased developmental and learning delays in infants born to mothers with ME/CFS.

Conclusion Current evidence on ME/CFS in pregnancy is limited, and findings are inconsistent. Studies are limited by small sample size and currently, there is no UK evidence. More high-quality research into ME/CFS and pregnancy is urgently needed to support the development of evidence-based guidelines on ME/CFS and pregnancy.

Source: Pearce M, Slack E, Pears K, et alOP72 Myalgic encephalomyelitis/chronic fatigue syndrome and pregnancy: a mixed-methods systematic reviewJ Epidemiol Community Health 2022;76:A35. https://jech.bmj.com/content/76/Suppl_1/A35.1