Tag: long covid review

Long COVID: mechanisms, risk factors and recovery

Abstract:

New findings: What is the topic of this review? The emerging condition of long COVID, its epidemiology, pathophysiological impacts on patients of different backgrounds, physiological mechanisms emerging as explanations of the condition, and treatment strategies being trialled. The review leads from a Physiological Society online conference on this topic. What advances does it highlight? Progress in understanding the pathophysiology and cellular mechanisms underlying Long COVID and potential therapeutic and management strategies.

Abstract: Long COVID, the prolonged illness and fatigue suffered by a small proportion of those infected with SARS-CoV-2, is placing an increasing burden on individuals and society. A Physiological Society virtual meeting in February 2022 brought clinicians and researchers together to discuss the current understanding of long COVID mechanisms, risk factors and recovery.

This review highlights the themes arising from that meeting. It considers the nature of long COVID, exploring its links with other post-viral illnesses such as myalgic encephalomyelitis/chronic fatigue syndrome, and highlights how long COVID research can help us better support those suffering from all post-viral syndromes. Long COVID research started particularly swiftly in populations routinely monitoring their physical performance – namely the military and elite athletes.

The review highlights how the high degree of diagnosis, intervention and monitoring of success in these active populations can suggest management strategies for the wider population. We then consider how a key component of performance monitoring in active populations, cardiopulmonary exercise training, has revealed long COVID-related changes in physiology – including alterations in peripheral muscle function, ventilatory inefficiency and autonomic dysfunction. The nature and impact of dysautonomia are further discussed in relation to postural orthostatic tachycardia syndrome, fatigue and treatment strategies that aim to combat sympathetic overactivation by stimulating the vagus nerve.

We then interrogate the mechanisms that underlie long COVID symptoms, with a focus on impaired oxygen delivery due to micro-clotting and disruption of cellular energy metabolism, before considering treatment strategies that indirectly or directly tackle these mechanisms. These include remote inspiratory muscle training and integrated care pathways that combine rehabilitation and drug interventions with research into long COVID healthcare access across different populations.

Overall, this review showcases how physiological research reveals the changes that occur in long COVID and how different therapeutic strategies are being developed and tested to combat this condition.

Source: Astin R, Banerjee A, Baker MR, Dani M, Ford E, Hull JH, Lim PB, McNarry M, Morten K, O’Sullivan O, Pretorius E, Raman B, Soteropoulos DS, Taquet M, Hall CN. Long COVID: mechanisms, risk factors and recovery. Exp Physiol. 2022 Nov 22. doi: 10.1113/EP090802. Epub ahead of print. PMID: 36412084. https://physoc.onlinelibrary.wiley.com/doi/10.1113/EP090802 (Full text)

COVID-19 disease severity to predict persistent symptoms: a systematic review and meta-analysis

Abstract:

Background: It is unclear, whether the initial disease severity may help to predict which COVID-19 patients at risk of developing persistent symptoms.

Aim: The aim of this study was to examine whether the initial disease severity affects the risk of persistent symptoms in post-acute COVID-19 syndrome and long COVID.

Methods: A systematic search was conducted using PUBMED, Google Scholar, EMBASE, and ProQuest databases to identify eligible articles published after January 2020 up to and including 30 August 2021. Pooled odds ratio (OR) and confidence intervals (CIs) were calculated using random effects meta-analysis.

Findings: After searching a total of 7733 articles, 20 relevant observational studies with a total of 7840 patients were selected for meta-analysis. The pooled OR for persistent dyspnea in COVID-19 survivors with a severe versus nonsevere initial disease was 2.17 [95%CI 1.62 to 2.90], and it was 1.33 [95%CI 0.75 to 2.33] for persistent cough, 1.30 [95%CI 1.06 to 1.58] for persistent fatigue, 1.02 [95%CI 0.73 to 1.40] for persistent anosmia, 1.22 [95%CI 0.69 to 2.16] for persistent chest pain, and 1.30 [95%CI 0.93 to 1.81] for persistent palpitation.

Conclusions: Contrary to expectations, we did not observe an association between the initial COVID-19 disease severity and common persistent symptoms except for dyspnea and fatigue. In addition, it was found that being in the acute or prolonged post-COVID phase did not affect the risk of symptoms. Primary care providers should be alert to potential most prevalent persistent symptoms in all COVID-19 survivors, which are not limited to patients with critical-severe initial disease.

Source: Dirican E, Bal T. COVID-19 disease severity to predict persistent symptoms: a systematic review and meta-analysis. Prim Health Care Res Dev. 2022 Nov 10;23:e69. doi: 10.1017/S1463423622000585. PMID: 36352492.  https://www.cambridge.org/core/journals/primary-health-care-research-and-development/article/covid19-disease-severity-to-predict-persistent-symptoms-a-systematic-review-and-metaanalysis/479FC1E900E22673895FDAC1CF5C12B2 (Full text)

Role of neuroinflammation mediated potential alterations in adult neurogenesis as a factor for neuropsychiatric symptoms in Post-Acute COVID-19 syndrome-A narrative review

Abstract:

Persistence of symptoms beyond the initial 3 to 4 weeks after infection is defined as post-acute COVID-19 syndrome (PACS). A wide range of neuropsychiatric symptoms like anxiety, depression, post-traumatic stress disorder, sleep disorders and cognitive disturbances have been observed in PACS. The review was conducted based on PRISMA-S guidelines for literature search strategy for systematic reviews.

A cytokine storm in COVID-19 may cause a breach in the blood brain barrier leading to cytokine and SARS-CoV-2 entry into the brain. This triggers an immune response in the brain by activating microglia, astrocytes, and other immune cells leading to neuroinflammation. Various inflammatory biomarkers like inflammatory cytokines, chemokines, acute phase proteins and adhesion molecules have been implicated in psychiatric disorders and play a major role in the precipitation of neuropsychiatric symptoms. Impaired adult neurogenesis has been linked with a variety of disorders like depression, anxiety, cognitive decline, and dementia.

Persistence of neuroinflammation was observed in COVID-19 survivors 3 months after recovery. Chronic neuroinflammation alters adult neurogenesis with pro-inflammatory cytokines supressing anti-inflammatory cytokines and chemokines favouring adult neurogenesis. Based on the prevalence of neuropsychiatric symptoms/disorders in PACS, there is more possibility for a potential impairment in adult neurogenesis in COVID-19 survivors. This narrative review aims to discuss the various neuroinflammatory processes during PACS and its effect on adult neurogenesis.

Source: Saikarthik J, Saraswathi I, Alarifi A, Al-Atram AA, Mickeymaray S, Paramasivam A, Shaikh S, Jeraud M, Alothaim AS. Role of neuroinflammation mediated potential alterations in adult neurogenesis as a factor for neuropsychiatric symptoms in Post-Acute COVID-19 syndrome-A narrative review. PeerJ. 2022 Nov 4;10:e14227. doi: 10.7717/peerj.14227. PMID: 36353605; PMCID: PMC9639419. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9639419/ (Full text)

Clinical trials on the pharmacological treatment of long COVID: A systematic review

Abstract:

The postacute sequelae of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (PASC), also known as post-acute coronavirus disease 19 (COVID-19) or the long COVID syndrome (long COVID) is an emerging public health concern. A substantial proportion of individuals may remain symptomatic months after initial recovery. An updated review of published and ongoing trials focusing on managing long COVID will help identify gaps and address the unmet needs of patients suffering from this potentially debilitating syndrome.

A comprehensive literature search was conducted on the international databases and clinical trial registries from inception to 31 July 2022. This review included 6 published trials and 54 trial registration records. There is significant heterogeneity in the characterization of long COVID and ascertainment of primary outcomes. Most of the trials are focused on individual symptoms of long COVID or isolated organ dysfunction, classified according to cardiovascular, respiratory and functional capacity, neurological and psychological, fatigue, and olfactory dysfunction.

Most of the interventions are related to the mechanisms causing the individual symptoms. Although the six published trials showed significant improvement in the symptoms or organ dysfunction studied, these initial studies lack internal and external validity limiting the generalizability. This review provides an update of the pharmacological agents that could be used to treat long COVID. Further standardization of the diagnostic criteria, inclusion of participants with concomitant chronic cardiometabolic diseases and standardization of outcomes will be essential in future clinical trials.

Source: Chee YJ, Fan BE, Young BE, Dalan R, Lye DC. Clinical trials on the pharmacological treatment of long COVID: A systematic review. J Med Virol. 2022 Nov 8:e28289. doi: 10.1002/jmv.28289. Epub ahead of print. PMID: 36349400. https://pubmed.ncbi.nlm.nih.gov/36349400/

Is Long COVID Syndrome a Transient Mitochondriopathy Newly Discovered: Implications of CPET

Abstract:

The new outbreak of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has an impact worldwide, primarily as a medical emergency. Even that the total constellation is considered as a pandemic of acute respiratory disease, coronavirus disease 2019 (COVID-19) gives rise to dysfunction in multiple organs (e.g., brain, lungs, heart, muscles) that impairs cardiopulmonary (CP) function. Parallel to the CP consequences of COVID-19 is a significant reduction in physical activity.

Cardiopulmonary exercise testing (CPET) is daily used in clinical practice to define prognosis, provide risk stratification and treatment strategy. As such, the significance of CPET is crucial concerning clinical assessments of COVID-19 patients. Furthermore, new studies aim at understanding the effects of SARS-CoV-2 infection in long term. Multiple studies have investigated the cardiopulmonary function and impairment of exercise endurance in such patients, as well as a possible prolonged physical impairment. With this review, we summarize the COVID-19-associated pathophysiology for the Long COVID (LC) syndrome as well as the importance of performing CPET.

Source: Stefanos G. Sakellaropoulos, Muhammad Ali, Athanasios Papadis, Muhemin Mohammed, Andreas Mitsis, Zaza Zivzivadze. Is Long COVID Syndrome a Transient Mitochondriopathy Newly Discovered: Implications of CPET. Cardiology Research, ISSN 1923-2829 print, Volume 13, Number 5, October 2022, pages 264-267.  https://www.cardiologyres.org/index.php/Cardiologyres/article/view/1419/1360 (Full text)

The Psychiatric Consequences of Long-COVID: A Scoping Review

Abstract:

The COVID-19 pandemic has represented a new form of traumatic event, affecting the general population worldwide and causing severe disruption of daily routine. A new urgent concern is related to the burden associated with COVID-19 symptoms that persist beyond the onset of infection, the so-called long-COVID syndrome.
The present paper aims to: (1) describe the most frequent psychiatric symptoms reported by patients affected by long-COVID syndrome; (2) evaluate methodological discrepancies among the available studies; (3) inform clinicians and policy-makers on the possible strategies to be promoted in order to manage the psychiatric consequences of long-COVID syndrome.
Twenty-one papers have been included in the present review, mostly with a cross-sectional or cohort design. Significant heterogeneity of long-COVID syndrome definitions was found. The presence of psychiatric symptoms was evaluated with very different assessment tools.
The most common psychiatric symptoms of the long-COVID syndrome included fatigue, cognitive disturbances/impairment, depression, and anxiety symptoms. The rate of fatigue varied from 93.2–82.3% to 11.5%, cognitive impairment/cognitive dysfunction from 61.4% to 23.5% and depressive-anxiety symptoms from 23.5%to 9.5%
Source: Sampogna G, Di Vincenzo M, Giallonardo V, Perris F, Volpicelli A, Del Vecchio V, Luciano M, Fiorillo A. The Psychiatric Consequences of Long-COVID: A Scoping Review. Journal of Personalized Medicine. 2022; 12(11):1767. https://doi.org/10.3390/jpm12111767  https://www.mdpi.com/2075-4426/12/11/1767/htm (Full text)

Psychiatric and neurological complications of long COVID

Abstract:

COVID-19 was primarily considered a pulmonary disease with extrapulmonary manifestations. As the pandemic spread, there has been growing evidence that the disease affects various organs/systems, including the central and peripheral nervous systems. Accumulation of clinical data demonstrates that in a large population of survivors impairments in the function of one or more organs may persist for a long time, a phenomenon commonly known as post COVID or long COVID.

Fatigue and cognitive dysfunction, such as concentration problems, short-term memory deficits, general memory loss, a specific decline in attention, language and praxis abilities, encoding and verbal fluency, impairment of executive functions, and psychomotor coordination, are amongst the most common and debilitating features of neuropsychatric symptoms of post COVID syndrome. Several patients also suffer from compromised sleep, depression, anxiety and post-traumatic stress disorder. Patients with long COVID may demonstrate brain hypometabolism, hypoperfusion of the cerebral cortex and changes in the brain structure and functional connectivity.

Children and adolescents represent a minority of COVID-19 cases, so not surprisingly data on the long-term sequelae after SARS-CoV-2 infections in these age groups are scarce. Although the pathogenesis, clinical characteristics, epidemiology, and risk factors of the acute phase of COVID-19 have been largely explained, these areas are yet to be explored in long COVID. This review aims to provide an update on what is currently known about long COVID effects on mental health.

Source: Zawilska JB, Kuczyńska K. Psychiatric and neurological complications of long COVID. J Psychiatr Res. 2022 Oct 20;156:349-360. doi: 10.1016/j.jpsychires.2022.10.045. Epub ahead of print. PMID: 36326545; PMCID: PMC9582925. https://www.sciencedirect.com/science/article/pii/S0022395622005982 (Full text)

Global prevalence of chronic fatigue syndrome among long COVID-19 patients: A systematic review and meta-analysis

Abstract:

Background: Chronic fatigue syndrome is a persistent and debilitating disorder. According to several studies, chronic fatigue syndrome has been identified among recovered COVID-19 patients as the most common symptom of long COVID. The aim of this systematic review and meta-analysis study was to obtain the prevalence of chronic fatigue syndrome in long COVID cases.

Methods: In this systematic review and meta-analysis, we analysed reported results of studies that assessed the occurrence of chronic fatigue syndrome among COVID-19 patients four weeks after the onset of symptoms. The study selection was commenced by searching PubMed, Web of Science, Science Direct, Scopus, Embase, and Google scholar using the keywords of Chronic fatigue syndrome, COVID-19, and post-COVID-19 syndrome. The searches were without a lower time limit and until April 2022. Heterogeneity of studies was assessed using the I2 index, and a random effects model was used for analysis. Data analysis was performed within the Comprehensive Meta-Analysis software (version 2).

Results: The pooled prevalence of chronic fatigue syndrome four weeks after the onset of COVID-19 symptoms, in 52 studies with a sample size of 127,117, was 45.2% (95% CI: 34.1-56.9%). Meta-regression analysis in examining the effects of the two factors of sample size, and year of study on the changes in the overall prevalence, showed that with increasing sample size, and year of study, the prevalence of chronic fatigue syndrome among long COVID patients (p < 0.05).

Conclusion: Our results show that the overall prevalence of chronic fatigue syndrome as a long COVID symptom is 45.2%. Chronic fatigue after infection with COVID-19 can negatively affect personal and social lives. Given such significant negative consequences caused by the syndrome, it is recommended that health policymakers allocate funds to reduce the adverse effects of this syndrome, by creating programs to support long COVID patients.

Source: Salari N, Khodayari Y, Hosseinian-Far A, Zarei H, Rasoulpoor S, Akbari H, Mohammadi M. Global prevalence of chronic fatigue syndrome among long COVID-19 patients: A systematic review and meta-analysis. Biopsychosoc Med. 2022 Oct 23;16(1):21. doi: 10.1186/s13030-022-00250-5. PMID: 36274177; PMCID: PMC9589726. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9589726/ (Full text)

Use of Cardiopulmonary Exercise Testing to Evaluate Long COVID-19 Symptoms in Adults: A Systematic Review and Meta-analysis

Abstract

Importance: Reduced exercise capacity is commonly reported among individuals with COVID-19 symptoms more than 3 months after SARS-CoV-2 infection (long COVID-19 [LC]). Cardiopulmonary exercise testing (CPET) is the criterion standard to measure exercise capacity and identify patterns of exertional intolerance.

Objectives: To estimate the difference in exercise capacity among individuals with and without LC symptoms and characterize physiological patterns of limitations to elucidate possible mechanisms of LC.

Data sources: A search of PubMed, EMBASE, Web of Science, preprint servers, conference abstracts, and cited references was performed on December 20, 2021, and again on May 24, 2022. A preprint search of medrxiv.org, biorxiv.org, and researchsquare.com was performed on June 9, 2022.

Study selection: Studies of adults with SARS-CoV-2 infection more than 3 months earlier that included CPET-measured peak oxygen consumption (V̇o2) were screened independently by 2 blinded reviewers; 72 (2%) were selected for full-text review, and 35 (1%) met the inclusion criteria. An additional 3 studies were identified from preprint servers.

Data extraction and synthesis: Data extraction was performed by 2 independent reviewers according to the PRISMA reporting guideline. Data were pooled using random-effects models.

Main outcomes and measures: Difference in peak V̇o2 (in mL/kg/min) among individuals with and without persistent COVID-19 symptoms more than 3 months after SARS-CoV-2 infection.

Results: A total of 38 studies were identified that performed CPET on 2160 individuals 3 to 18 months after SARS-CoV-2 infection, including 1228 with symptoms consistent with LC. Most studies were case series of individuals with LC or cross-sectional assessments within posthospitalization cohorts. Based on a meta-analysis of 9 studies including 464 individuals with LC symptoms and 359 without symptoms, the mean peak V̇o2 was -4.9 (95% CI, -6.4 to -3.4) mL/kg/min among those with symptoms with a low degree of certainty. Deconditioning and peripheral limitations (abnormal oxygen extraction) were common, but dysfunctional breathing and chronotropic incompetence were also described. The existing literature was limited by small sample sizes, selection bias, confounding, and varying symptom definitions and CPET interpretations, resulting in high risk of bias and heterogeneity.

Conclusions and relevance: The findings of this systematic review and meta-analysis study suggest that exercise capacity was reduced more than 3 months after SARS-CoV-2 infection among individuals with symptoms consistent with LC compared with individuals without LC symptoms, with low confidence. Potential mechanisms for exertional intolerance other than deconditioning include altered autonomic function (eg, chronotropic incompetence, dysfunctional breathing), endothelial dysfunction, and muscular or mitochondrial pathology.

Source: Durstenfeld MS, Sun K, Tahir P, Peluso MJ, Deeks SG, Aras MA, Grandis DJ, Long CS, Beatty A, Hsue PY. Use of Cardiopulmonary Exercise Testing to Evaluate Long COVID-19 Symptoms in Adults: A Systematic Review and Meta-analysis. JAMA Netw Open. 2022 Oct 3;5(10):e2236057. doi: 10.1001/jamanetworkopen.2022.36057. PMID: 36223120. https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2797203 (Full text)

Symptomatology and microbiology of the gastrointestinal tract in post-COVID conditions

Abstract:

Post-COVID conditions, also known as post-acute sequelae of SARS-CoV-2 (PASC), refer to the persistence of symptoms in COVID-19 long-haulers. Various manifestations of post-COVID conditions are general symptoms and/or manifestations of damage in multiple organs. Besides, SARS-CoV-2 can involve the gastrointestinal tract, resulting in sequelae such as diarrhea, abdominal pain, nausea, anorexia, vomiting, constipation, abdominal distension, acid reflux, and/or gastrointestinal bleeding.
Previous investigations point to SARS-CoV-2 entry into enterocytes enhances by the angiotensin-converting enzyme 2 (ACE2) receptors. Interestingly, ACE2 receptors are abundantly expressed in the gut, implying infection with SARS-CoV-2 might occur through this route as well as in the respiratory tract. According to mounting evidence, SARS-CoV-2 RNA has been identified in fecal specimens of patients with COVID-19 during and beyond the acute phase.
In addition, studies have shown gut microbiome composition is altered in patients with PASC, hence, another putative mechanism linked to gastrointestinal symptoms is gut dysbiosis. The presence of the gut-lung axis in COVID-19 might have major implications for disease pathogenesis and treatment.
This review discussed the prevalence of gastrointestinal symptoms and pathophysiology underlying possible infection of the gut in patients with PASC. Also, SARS-COV-2 induced NLRP3 inflammasome-dependent inflammatory pathways are briefly addressed.
Source: Norouzi Masir M, Shirvaliloo M. Symptomatology and microbiology of the gastrointestinal tract in post-COVID conditions. JGH Open : an Open Access Journal of Gastroenterology and Hepatology. 2022 Aug. DOI: 10.1002/jgh3.12811. PMID: 36247234; PMCID: PMC9538198. https://europepmc.org/article/pmc/pmc9538198 (Full text)