Tag: long Covid

Tryptophan catabolites, inflammation, and insulin resistance as determinants of chronic fatigue syndrome and affective symptoms in long COVID

Abstract:

Critical COVID-19 disease is accompanied by depletion of plasma tryptophan (TRY) and increases in indoleamine-dioxygenase (IDO)-stimulated production of neuroactive tryptophan catabolites (TRYCATs), including kynurenine (KYN). The TRYCAT pathway has not been studied extensively in association with the physiosomatic and affective symptoms of Long COVID.

In the present study, we measured serum TRY, TRYCATs, insulin resistance (using the Homeostatic Model Assessment Index 2-insulin resistance, HOMA2-IR), C-reactive protein (CRP), physiosomatic, depression, and anxiety symptoms in 90 Long COVID patients, 3–10 months after remission of acute infection.

We were able to construct an endophenotypic class of severe Long COVID (22% of the patients) with very low TRY and oxygen saturation (SpO2, during acute infection), increased kynurenine, KYN/TRY ratio, CRP, and very high ratings on all symptom domains. One factor could be extracted from physiosomatic symptoms (including chronic fatigue-fibromyalgia), depression, and anxiety symptoms, indicating that all domains are manifestations of the common physio-affective phenome.

Three Long COVID biomarkers (CRP, KYN/TRY, and IR) explained around 40% of the variance in the physio-affective phenome. The latter and the KYN/TRY ratio were significantly predicted by peak body temperature (PBT) and lowered SpO2 during acute infection. One validated latent vector could be extracted from the three symptom domains and a composite based on CRP, KYN/TRY, and IR (Long COVID), and PBT and SpO2 (acute COVID-19).

In conclusion, the physio-affective phenome of Long COVID is a manifestation of inflammatory responses during acute and Long COVID, and lowered plasma tryptophan and increased kynurenine may contribute to these effects.

Source: Al-Hakeim HK, Khairi Abed A, Rouf Moustafa S, Almulla AF, Maes M. Tryptophan catabolites, inflammation, and insulin resistance as determinants of chronic fatigue syndrome and affective symptoms in long COVID. Front Mol Neurosci. 2023 Jun 2;16:1194769. doi: 10.3389/fnmol.2023.1194769. PMID: 37333619; PMCID: PMC10272345. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10272345/ (Full text)

Posttreatment Lyme disease syndrome and myalgic encephalomyelitis/chronic fatigue syndrome: A systematic review and comparison of pathogenesis

Abstract:

Lyme disease is the most common vector-borne illness in the United States and has been causing significant morbidity since its discovery in 1977. It is well-documented that about 10% of patients properly treated with antibiotics never fully recover, but instead go on to develop a chronic illness dubbed, posttreatment Lyme disease syndrome (PTLDS) characterized by severe fatigue, cognitive slowing, chronic pain, and sleep difficulties. This review includes 18 studies that detail the symptoms of patients with PTLDS and uses qualitative analysis to compare them to myalgic encephalitis/chronic fatigue syndrome (ME/CFS), a strikingly similar syndrome.

In the majority of the PTLDS studies, at least four of the six major symptoms of ME/CFS were also noted, including substantial impairment in activity level and fatigue for more than 6 months, post-exertional malaise, and unrefreshing sleep. In one of the included PTLDS articles, 26 of the 29 ME/CFS symptoms were noted. This study adds to the expanding literature on the post-active phase of infection syndromes, which suggests that chronic illnesses such as PTLDS and ME/CFS have similar pathogenesis despite different infectious origins.

Key points

  • This systematic review uses qualitative analysis to compare posttreatment Lyme disease syndrome to myalgic encephalitis/chronic fatigue syndrome, both of which are post-active phases of infection syndromes.
  • The result of this review suggests that chronic illnesses such as PTLDS and ME/CFS have similar pathogenesis despite different infectious origins.

Source: Bai, NA, Richardson, CS. Posttreatment Lyme disease syndrome and myalgic encephalomyelitis/chronic fatigue syndrome: A systematic review and comparison of pathogenesis. Chronic Dis Transl Med. 2023; 1– 8. doi:10.1002/cdt3.74 https://onlinelibrary.wiley.com/doi/full/10.1002/cdt3.74 (Full text)

Vagus Nerve Dysfunction in the Post-COVID-19 Condition

Abstract:

Background: The post-COVID-19 condition (PCC) is a disabling syndrome affecting 5-15% of subjects who survive COVID-19. SARS-CoV-2 mediated vagus nerve dysfunction could explain some of the PCC symptoms, including persistent dysphonia, dysphagia, dyspnea, dizziness, tachycardia, orthostatic hypotension, gastrointestinal disturbances or neurocognitive complaints.

Methods: We performed a cross-sectional pilot study in subjects with PCC with symptoms suggesting vagus nerve dysfunction (n=30) and compared them to subjects fully recovered from acute COVID-19 (n=14) and individuals never infected with SARS-CoV-2 (n=16), matched by age and sex. We evaluated the structure and function of the vagus nerve, including dysphonia, dysphagia, and dysautonomia tests, and evaluated the structure and function of respiratory muscles with vagus nerve innervation.

Findings: Participants were mostly (80%) women with median 44 years of age. Their most prevalent symptoms were cognitive dysfunction (83%), dyspnea (80%) and tachycardia (80%). Compared with COVID-19-recovered and uninfected controls, respectively, subjects with PCC were more likely to show thickening and hyperechogenic vagus nerve in neck ultrasounds (mean ± SD left vagus nerve cross-sectional area: 2.4 ± 0.97mm2 vs. 2 ± 0.52mm2 vs. 1.9 ± 0.73 mm2, p=0.080), flattened diaphragmatic curve (47% vs 6% vs 14%, p=0.007), reduced esophageal peristalsis (34% vs 0% vs 21%, p=0.020), gastroesophageal reflux (34% vs 19% vs 7%, p=0.130), hiatal hernia (25% vs 0% vs 7%, p=0.050) and reduced maximal inspiratory pressure in functional respiratory tests (62% vs. 6% vs. 17%, p ≤0.001).

Interpretation: Vagus nerve dysfunction has a central pathogenic role in the pathophysiology of the post-COVID condition.

Source: Lladós, Gemma and Massanella, Marta and Coll-Fernández, Roser and Rodríguez, Raúl and Hernández, Electra and Lucente, Giuseppe and López, Cristina and Loste, Cora and Santos, José Ramón and España-Cueto, Sergio and Nevot, Maria and Muñoz-López, Francisco and Arrieta, Sandra Silva and Brander, Christian and Durà, Maria José and Cuadras, Patricia and Bechini, Jordi and Tenesa, Montserrat and Martinez-Piñeiro, Alicia and Herrero, Cristina and Chamorro, Anna and Garcia, Anna and Grau, Eulalia and Clotet, Bonaventura and Paredes, Roger and Mateu, Lourdes and Unit, Germans Trias Long-COVID, Vagus Nerve Dysfunction in the Post-COVID-19 Condition. Available at SSRN: https://ssrn.com/abstract=4479598 or http://dx.doi.org/10.2139/ssrn.4479598

“We’re drowning and we’re alone”: a qualitative study of the lived experience of people experiencing persistent post-COVID-19 symptoms

Abstract:

Background: The “long tail” of the COVID-19 pandemic will be reflected in disabling symptoms that persist, fluctuate or recur for extended periods for an estimated 20%-30% of those who had a SARS-CoV-2 infection; development of effective interventions to address these symptoms must account for the realities faced by these patients. We sought to describe the lived experience of patients living with persistent post-COVID-19 symptoms.

Methods: We conducted a qualitative study, using interpretive description, of the lived experiences of adults experiencing persistent post-COVID-19 symptoms. We collected data from in-depth, semistructured virtual focus groups in February and March 2022. We used thematic analysis to analyze the data and met with several participants twice for respondent validation.

Results: The study included 41 participants (28 females) from across Canada with a mean age of 47.9 years and mean time since initial SARS-CoV-2 infection of 15.8 months. Four overarching themes were identified: the unique burdens of living with persistent post-COVID-19 symptoms; the complex nature of patient work in managing symptoms and seeking treatment during recovery; erosion of trust in the health care system; and the process of adaptation, which included taking charge and transformed self-identity.

Interpretation: Living with persistent post-COVID-19 symptoms within a health care system ill-equipped to provide needed resources profoundly challenges the ability of survivors to restore their well-being. Whereas policy and practice increasingly emphasize the importance of self-management within the context of post-COVID-19 symptoms, new investments that enhance services and support patient capacity are required to promote better outcomes for patients, the health care system and society.

Source: Goodridge D, Lowe TN, Cai S, Herriot FN, Silverberg RV, Heynen M, Hall KC, Peters J, Butcher S, Oyedokun T. “We’re drowning and we’re alone”: a qualitative study of the lived experience of people experiencing persistent post-COVID-19 symptoms. CMAJ Open. 2023 Jun 13;11(3):E504-E515. doi: 10.9778/cmajo.20220205. PMID: 37311595; PMCID: PMC10270655. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10270655/ (Full text)

Coronary microvascular health in symptomatic patients with prior COVID-19 infection: an updated analysis

Abstract:

Aims: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is associated with endothelial dysfunction. We aimed to determine the effects of prior coronavirus disease 2019 (COVID-19) on the coronary microvasculature accounting for time from COVID-19, disease severity, SARS-CoV-2 variants, and in subgroups of patients with diabetes and those with no known coronary artery disease.

Methods and results: Cases consisted of patients with previous COVID-19 who had clinically indicated positron emission tomography (PET) imaging and were matched 1:3 on clinical and cardiovascular risk factors to controls having no prior infection. Myocardial flow reserve (MFR) was calculated as the ratio of stress to rest myocardial blood flow (MBF) in mL/min/g of the left ventricle. Comparisons between cases and controls were made for the odds and prevalence of impaired MFR (MFR < 2). We included 271 cases matched to 815 controls (mean ± SD age 65 ± 12 years, 52% men). The median (inter-quartile range) number of days between COVID-19 infection and PET imaging was 174 (58-338) days. Patients with prior COVID-19 had a statistically significant higher odds of MFR <2 (adjusted odds ratio 3.1, 95% confidence interval 2.8-4.25 P < 0.001). Results were similar in clinically meaningful subgroups. The proportion of cases with MFR <2 peaked 6-9 months from imaging with a statistically non-significant downtrend afterwards and was comparable across SARS-CoV-2 variants but increased with increasing severity of infection.

Conclusion: The prevalence of impaired MFR is similar by duration of time from infection up to 1 year and SARS-CoV-2 variants, but significantly differs by severity of infection.

Source: Ahmed AI, Al Rifai M, Alahdab F, Saad JM, Han Y, Alfawara MS, Nayfeh M, Malahfji M, Nabi F, Mahmarian JJ, Cooke JP, Zoghbi WA, Al-Mallah MH. Coronary microvascular health in symptomatic patients with prior COVID-19 infection: an updated analysis. Eur Heart J Cardiovasc Imaging. 2023 May 31:jead118. doi: 10.1093/ehjci/jead118. Epub ahead of print. PMID: 37254693. https://pubmed.ncbi.nlm.nih.gov/37254693/

Clinical Features of Post-Covid Syndrome

Abstract:

There is no common understanding of the clinical picture of post-covid syndrome. The US regulator CDC proposes to highlight:

(A) persistent symptoms and conditions that begin during acute COVID-19 illness;

B) new onset late complications after asymptomatic disease or a period of acute symptomatic relief or remission;

(C) the evolution of symptoms and conditions that include some persistent symptoms (eg, shortness of breath) with the addition of new symptoms or conditions over time (eg, cognitive difficulties).

Some manifestations may resemble other postviral syndromes such as myalgic encephalomyelitis/chronic fatigue syndrome, dysautonomia (eg, postural orthostatic tachycardia syndrome), or mast cell activation syndrome.

Source: Sayfulloyevich, P. S. ., & Musayevich, U. R. . (2023). Clinical Features of Post-Covid Syndrome. EUROPEAN JOURNAL OF INNOVATION IN NONFORMAL EDUCATION, 3(6), 34–36. Retrieved from http://inovatus.es/index.php/ejine/article/view/1786 http://inovatus.es/index.php/ejine/article/view/1786/1794 (Full text)

Pre-assessment and management of long COVID patients requiring elective surgery: challenges and guidance

Abstract:

Whilst most patients infected with COVID-19 make a full recovery, around 1 in 33 patients in the UK report ongoing symptoms post-infection, termed ‘long COVID’. Studies have demonstrated that infection with early COVID-19 variants increases postoperative mortality and pulmonary complications for around 7 weeks after acute infection. Furthermore, this increased risk persists for those with ongoing symptoms beyond 7 weeks. Patients with long COVID may therefore also be at increased postoperative risk, and despite the significant prevalence of long COVID, there are minimal guidelines on how best to assess and manage these patients perioperatively.

Long COVID shares several clinical and pathophysiological similarities with conditions such as myalgic encephalitis/chronic fatigue syndrome and postural tachycardia syndrome; however, there are no current guidelines for the preoperative management of these patients to help develop something similar for long COVID patients. Developing guidelines for long COVID patients is further complicated by its heterogenous presentation and pathology. These patients can have persistent abnormalities on pulmonary function tests and echocardiography 3 months after acute infection, correlating with a reduced functional capacity.

Conversely, some long COVID patients can continue to experience symptoms of dyspnoea and fatigue despite normal pulmonary function tests and echocardiography, yet demonstrating significantly reduced aerobic capacity on cardiopulmonary exercise testing even a year after initial infection. How to comprehensively risk assess these patients is therefore challenging.

Existing preoperative guidelines for elective patients with recent COVID-19 generally focus on the timing of surgery and recommendations for pre-assessment if surgery is required before this time interval has elapsed. How long to delay surgery in those with ongoing symptoms and how to manage them perioperatively are less clear.

We suggest that multidisciplinary decision-making is required for these patients, using a systems-based approach to guide discussion with specialists and the need for further preoperative investigations. However, without a better understanding of the postoperative risks for long COVID patients, it is difficult to obtain a multidisciplinary consensus and obtain informed patient consent. Prospective studies of long COVID patients undergoing elective surgery are urgently required to help quantify their postoperative risk and develop comprehensive perioperative guidelines for this complex patient group.

Source: Boles S, Ashok SR. Pre-assessment and management of long COVID patients requiring elective surgery: challenges and guidance. Perioper Med (Lond). 2023 Jun 5;12(1):20. doi: 10.1186/s13741-023-00305-3. PMID: 37277879; PMCID: PMC10241122. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10241122/ (Full text)

Scientific Rationale for the Treatment of Cognitive Deficits from Long COVID

Abstract:

Sustained cognitive deficits are a common and debilitating feature of “long COVID”, but currently there are no FDA-approved treatments. The cognitive functions of the dorsolateral prefrontal cortex (dlPFC) are the most consistently afflicted by long COVID, including deficits in working memory, motivation, and executive functioning. COVID-19 infection greatly increases kynurenic acid (KYNA) and glutamate carboxypeptidase II (GCPII) in brain, both of which can be particularly deleterious to PFC function.
KYNA blocks both NMDA and nicotinic-alpha-7 receptors, the two receptors required for dlPFC neurotransmission, and GCPII reduces mGluR3 regulation of cAMP-calcium-potassium channel signaling, which weakens dlPFC network connectivity and reduces dlPFC neuronal firing. Two agents approved for other indications may be helpful in restoring dlPFC physiology: the antioxidant N-acetyl cysteine inhibits the production of KYNA, and the α2A-adrenoceptor agonist guanfacine regulates cAMP-calcium-potassium channel signaling in dlPFC and is also anti-inflammatory. Thus, these agents may be helpful in treating the cognitive symptoms of long COVID.
Source: Fesharaki Zadeh A, Arnsten AFT, Wang M. Scientific Rationale for the Treatment of Cognitive Deficits from Long COVID. Neurology International. 2023; 15(2):725-742. https://doi.org/10.3390/neurolint15020045 https://www.mdpi.com/2035-8377/15/2/45 (Full text)

Long COVID: Complications, Underlying Mechanisms, and Treatment Strategies

Abstract:

Long Covid is one of the most prevalent and puzzling conditions that arose with the Covid pandemic. Covid-19 infection generally resolves within several weeks but some experience new or lingering symptoms. Though there is no formal definition for such lingering symptoms the CDC boadly describes long Covid as persons having a wide range of new, recurring or sustained health issues four or more weeks after first being infected with SARS-CoV2. The WHO defines long Covid as the manifestation of symptoms from a “probable or confirmed” Covid-19 infection that start approximately 3 months after the onset of the acute infection and last for more than 2 months.

Numerous studies have looked at the implications of long Covid on various organs. Many specific mechanisms have been proposed for such changes. In this article, we provide an overview of some of the main mechanisms by which long Covid induces end-organ damage proposed in recent research studies. We also review various treatment options, current clinical trials, and other potential therapeutic avenues to control long Covid followed by the information about the effect of vaccination on long Covid.

Lastly, we discuss some of the questions and knowledge gaps in the present understanding of long Covid. We believe more studies of the effects long Covid has on quality of life, future health and life expectancy are required to better understand and eventually prevent or treat the disease. We acknowledge the effects of long Covid are not limited to those in this article but as it may affect the health of future offspring and therefore, we deem it important to identify more prognostic and therapeutic targets to control this condition.

Source: Farigol Hakem Zadeh, Daniel R. Wilson, Devendra K. Agrawal. Long COVID: Complications, Underlying Mechanisms, and Treatment Strategies. Archives of Microbiology and Immunology. 7 (2023): 36-61. http://www.fortunejournals.com/articles/long-covid-complications-underlying-mechanisms-and-treatment-strategies.html (Full text)

Long COVID syndrome after SARS-CoV-2 survival in patients with pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension

Abstract:

Pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) patients have a more severe COVID-19 course than the general population. Many patients report different persistent symptoms after SARS-CoV-2 infection. The aim of our study is to analyze the prevalence of long COVID-19 symptoms and assess if COVID-19 affects pulmonary hypertension (PH) prognosis.

PAH/CTEPH patients who survived COVID-19 for at least 3 months before visiting the PH centers were included in the study. The patients were assessed for symptoms in acute phase of SARS-CoV-2 infection and persisting in follow-up visit, WHO functional class, 6-min walk distance, NT-proBNP concentration. The COMPERA 2.0 model was used to calculate 1-year risk of death due to PH at baseline and at follow-up. Sixty-nine patients-54 (77.3%) with PAH and 15 (21.7%) with CTEPH, 68% women, with a median age of 47.5 years (IQR 37-68)-were enrolled in the study.

About 17.1% of patients were hospitalized due to COVID-19 but none in an ICU. At follow-up (median: 155 days after onset of SARS-CoV-2 symptoms), 62% of patients reported at least 1 COVID-19-related symptom and 20% at least 5 symptoms. The most frequently reported symptoms were: fatigue (30%), joint pain (23%), muscle pain (17%), nasal congestion (17%), anosmia (13%), insomnia (13%), and dyspnea (12%).

Seventy-two percent of PH patients had a low or intermediate-low risk of 1-year death due to PH at baseline, and 68% after COVID-19 at follow-up. Over 60% of PAH/CTEPH patients who survived COVID-19 suffered from long COVID-19 syndrome, but the calculated 1-year risk of death due to PH did not change significantly after surviving mild or moderate COVID-19.

Source: Wieteska-Miłek M, Kuśmierczyk-Droszcz B, Betkier-Lipińska K, Szmit S, Florczyk M, Zieliński P, Hoffman P, Krzesińki P, Kurzyna M. Long COVID syndrome after SARS-CoV-2 survival in patients with pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension. Pulm Circ. 2023 May 31;13(2):e12244. doi: 10.1002/pul2.12244. PMID: 37266140; PMCID: PMC10232226. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10232226/ (Full text)