A pilot study on the immune cell proteome of long COVID patients shows changes to physiological pathways similar to those in myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

Of those infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), ~ 10% develop the chronic post-viral debilitating condition, long COVID (LC). Although LC is a heterogeneous condition, about half of cases have typical post-viral fatigue with onset and symptoms that are very similar to myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). A key question is whether these conditions are closely related. ME/CFS is a post-stressor fatigue condition that arises from multiple triggers.

To investigate the pathophysiology of LC, a pilot study of patients (n = 6) and healthy controls (n = 5) has used quantitative proteomics to discover changes in peripheral blood mononuclear cell (PBMC) proteins. A principal component analysis separated all long COVID patients from healthy controls. Analysis of 3131 proteins identified 162 proteins differentially regulated, of which 37 were related to immune functions, and 21 to mitochondrial functions.

Markov cluster analysis identified clusters involved in immune system processes, and two aspects of gene expression-spliceosome and transcription. These results were compared with an earlier dataset of 346 differentially regulated proteins in PBMC’s from ME/CFS patients (n = 9) analysed by the same methodology. There were overlapping protein clusters and enriched molecular pathways particularly in immune functions, suggesting the two conditions have similar immune pathophysiology as a prominent feature, and mitochondrial functions involved in energy production were affected in both conditions.

Source: Peppercorn, K., Edgar, C.D., Kleffmann, T. et al. A pilot study on the immune cell proteome of long COVID patients shows changes to physiological pathways similar to those in myalgic encephalomyelitis/chronic fatigue syndrome. Sci Rep 13, 22068 (2023). https://doi.org/10.1038/s41598-023-49402-9 https://www.nature.com/articles/s41598-023-49402-9 (Full text)

Dysautonomia following Lyme disease: a key component of post-treatment Lyme disease syndrome?

Abstract:

Dysautonomia, or dysfunction of the autonomic nervous system (ANS), may occur following an infectious insult and can result in a variety of debilitating, widespread, and often poorly recognized symptoms. Dysautonomia is now widely accepted as a complication of COVID-19 and is an important component of Post-Acute Sequelae of COVID-19 (PASC or long COVID).

PASC shares many overlapping clinical features with other infection-associated chronic illnesses including Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Post-Treatment Lyme Disease Syndrome (PTLDS), suggesting that they may share common underlying mechanisms including autonomic dysfunction.

Despite the recognition of this complication of Lyme disease in the care of patients with PTLD, there has been a scarcity of research in this field and dysautonomia has not yet been established as a complication of Lyme disease in the medical literature.

In this review, we discuss the evidence implicating Borrelia burgdorferi as a cause of dysautonomia and the related symptoms, propose potential pathogenic mechanisms given our knowledge of Lyme disease and mechanisms of PASC and ME/CFS, and discuss the diagnostic evaluation and treatments of dysautonomia. We also outline gaps in the literature and priorities for future research.

Source: Adler BL, Chung T, Rowe PC, Aucott J. Dysautonomia following Lyme disease: a key component of post-treatment Lyme disease syndrome? Front Neurol. 2024 Feb 8;15:1344862. doi: 10.3389/fneur.2024.1344862. PMID: 38390594; PMCID: PMC10883079. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10883079/ (Full text)

Prevalence of persistent SARS-CoV-2 in a large community surveillance study

Abstract:

Persistent SARS-CoV-2 infections may act as viral reservoirs that could seed future outbreaks1-5, give rise to highly divergent lineages6-8 and contribute to cases with post-acute COVID-19 sequelae (long COVID)9,10. However, the population prevalence of persistent infections, their viral load kinetics and evolutionary dynamics over the course of infections remain largely unknown.

Here, using viral sequence data collected as part of a national infection survey, we identified 381 individuals with SARS-CoV-2 RNA at high titre persisting for at least 30 days, of which 54 had viral RNA persisting at least 60 days. We refer to these as ‘persistent infections’ as available evidence suggests that they represent ongoing viral replication, although the persistence of non-replicating RNA cannot be ruled out in all.

Individuals with persistent infection had more than 50% higher odds of self-reporting long COVID than individuals with non-persistent infection. We estimate that 0.1-0.5% of infections may become persistent with typically rebounding high viral loads and last for at least 60 days. In some individuals, we identified many viral amino acid substitutions, indicating periods of strong positive selection, whereas others had no consensus change in the sequences for prolonged periods, consistent with weak selection. Substitutions included mutations that are lineage defining for SARS-CoV-2 variants, at target sites for monoclonal antibodies and/or are commonly found in immunocompromised people11-14. This work has profound implications for understanding and characterizing SARS-CoV-2 infection, epidemiology and evolution.

Source: Ghafari M, Hall M, Golubchik T, Ayoubkhani D, House T, MacIntyre-Cockett G, Fryer HR, Thomson L, Nurtay A, Kemp SA, Ferretti L, Buck D, Green A, Trebes A, Piazza P, Lonie LJ, Studley R, Rourke E, Smith DL, Bashton M, Nelson A, Crown M, McCann C, Young GR, Santos RAND, Richards Z, Tariq MA, Cahuantzi R; Wellcome Sanger Institute COVID-19 Surveillance Team; COVID-19 Infection Survey Group; COVID-19 Genomics UK (COG-UK) Consortium; Barrett J, Fraser C, Bonsall D, Walker AS, Lythgoe K. Prevalence of persistent SARS-CoV-2 in a large community surveillance study. Nature. 2024 Feb 21. doi: 10.1038/s41586-024-07029-4. Epub ahead of print. PMID: 38383783. https://www.nature.com/articles/s41586-024-07029-4 (Full text)

Mechanisms underlying exercise intolerance in long COVID: An accumulation of multisystem dysfunction

Abstract:

The pathogenesis of exercise intolerance and persistent fatigue which can follow an infection with the SARS-CoV-2 virus (“long COVID”) is not fully understood. Cases were recruited from a long COVID clinic (N = 32; 44 ± 12 years; 10 (31%) men), and age-/sex-matched healthy controls (HC) (N = 19; 40 ± 13 years; 6 (32%) men) from University College London staff and students.

We assessed exercise performance, lung and cardiac function, vascular health, skeletal muscle oxidative capacity, and autonomic nervous system (ANS) function. Key outcome measures for each physiological system were compared between groups using potential outcome means (95% confidence intervals) adjusted for potential confounders. Long COVID participant outcomes were compared to normative values.

When compared to HC, cases exhibited reduced oxygen uptake efficiency slope (1847 (1679, 2016) vs. 2176 (1978, 2373) mL/min, p = 0.002) and anaerobic threshold (13.2 (12.2, 14.3) vs. 15.6 (14.4, 17.2) mL/kg/min, p < 0.001), and lower oxidative capacity, measured using near infrared spectroscopy (τ: 38.7 (31.9, 45.6) vs. 24.6 (19.1, 30.1) s, p = 0.001). In cases, ANS measures fell below normal limits in 39%.

Long COVID is associated with reduced measures of exercise performance and skeletal muscle oxidative capacity in the absence of evidence of microvascular dysfunction, suggesting mitochondrial pathology. There was evidence of attendant ANS dysregulation in a significant proportion. These multisystem factors might contribute to impaired exercise tolerance in long COVID sufferers.

Source: Jamieson A, Al Saikhan L, Alghamdi L, Hamill Howes L, Purcell H, Hillman T, Heightman M, Treibel T, Orini M, Bell R, Scully M, Hamer M, Chaturvedi N, Montgomery H, Hughes AD, Astin R, Jones S. Mechanisms underlying exercise intolerance in long COVID: An accumulation of multisystem dysfunction. Physiol Rep. 2024 Feb;12(3):e15940. doi: 10.14814/phy2.15940. PMID: 38346773; PMCID: PMC10861355. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10861355/ (Full text)

Post-COVID-19 patients suffer from chemosensory, trigeminal, and salivary dysfunctions

Abstract:

Recent literature indicates that post-COVID-19 patients suffer from a plethora of complications, including chemosensory dysfunction. However, little attention has been given to understand the interactions between chemosensory, trigeminal, and salivary dysfunctions in these patients. The aims of this study were (1) to investigate the prevalence and combinations of chemosensory, trigeminal, and salivary dysfunctions, (2) to identify the odorants/tastants that are compromised, and (3) to explore possible associations between the four dysfunctions in post-COVID-19 patients.

One hundred post-COVID-19 patients and 76 healthy controls (pre-COVID-19) were included in this cross-sectional, case-controlled study. Participants’ smell, taste, trigeminal, and salivary functions were assessed. The patients had a significantly higher prevalence of parosmia (80.0%), hyposmia (42.0%), anosmia (53.0%), dysgeusia (34.0%), complete ageusia (3.0%), specific ageusia (27.0%), dysesthesia (11.0%) and dry mouth (18.0%) compared to controls (0.0% for all parameters, except 27.6% for hyposmia). Complete loss of bitter taste was the most prevalent specific ageusia (66.7%) and coffee was the most common distorted smell (56.4%). Seven different combinations of dysfunction were observed in the patients, the most common being a combination of olfactory and gustatory dysfunction (48.0%).

These findings indicate that post-COVID-19 patients experience a range of chemosensory, trigeminal, and salivary disturbances, occurring in various combinations.

Source: Rogn Å, Jensen JL, Iversen PO, Singh PB. Post-COVID-19 patients suffer from chemosensory, trigeminal, and salivary dysfunctions. Sci Rep. 2024 Feb 11;14(1):3455. doi: 10.1038/s41598-024-53919-y. PMID: 38342941; PMCID: PMC10859368. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10859368/ (Full text)

Cardiorespiratory abnormalities in ICU survivors of COVID-19 with Post-acute Sequelae of SARS-CoV-2 infection are unrelated to invasive mechanical ventilation

Abstract:

Post-acute Sequelae of SARS-CoV-2 infection (PASC) often leads to exertional intolerance and reduced exercise capacity, particularly in individuals previously admitted to an intensive care unit (ICU). However, the impact of invasive mechanical ventilation (IMV) on PASC-associated cardiorespiratory abnormalities during exercise remains poorly understood.

This single-center, cross-sectional study aimed to gather knowledge on this topic. Fifty-two patients with PASC recruited ~6 months after ICU discharge were clustered based on their need for IMV (PASC+IMV, n=27) or non-invasive support therapy (PASC+NIS, n=25). Patients underwent pulmonary function and cardiopulmonary exercise testing (CPX), and were compared to a reference group (CONTROL, n=19) comprising individuals of both sexes with similar age, comorbidities, and physical activity levels, but without a history of COVID-19 illness.

Individuals with PASC, irrespective of support therapy, presented with higher rates of cardiorespiratory abnormalities than CONTROL, especially dysfunctional breathing patterns, dynamic hyperinflation, reduced oxygen uptake and oxygen pulse, and blunted heart rate recovery (all P<0.05). Only the rate of abnormal oxygen pulse was greater among PASC+IMV than PASC+NIS (P=0.05). Mean estimates for all CPX variables were comparable between PASC-IMV and PASC-NIS (all P>0.05).

These findings indicate significant involvement of both central and peripheral factors, leading to exertional intolerance in individuals with PASC previously admitted to the ICU, regardless of their need for IMV.

Source: Longobardi I, Prado DMLD, de Andrade DCO, Goessler KF, de Oliveira Júnior GN, Azevedo RA, Leitão AE, Santos JVP, de Sá Pinto AL, Gualano B, Roschel H. Cardiorespiratory abnormalities in ICU survivors of COVID-19 with Post-acute Sequelae of SARS-CoV-2 infection are unrelated to invasive mechanical ventilation. Am J Physiol Heart Circ Physiol. 2024 Feb 9. doi: 10.1152/ajpheart.00073.2024. Epub ahead of print. PMID: 38334972. https://pubmed.ncbi.nlm.nih.gov/38334972/ (Full study available as PDF file)

The impact of “long COVID” on menstruation in Chinese female college students and the intervention of acupuncture

Abstract:

This study aimed to explore the potential application value of acupuncture in alleviating the impact of long COVID on women’s menstrual cycles, by investigating the occurrence of long COVID among female college students, its effects on menstruation, and the intervention of acupuncture. This cross-sectional study surveyed female college students with a history of coronavirus disease 2019 (COVID-19) before April 10, 2023.

A questionnaire was used to analyze demographic characteristics, post-COVID sequelaes, duration of symptoms, and treatments received during that period. Among the 731 participants enrolled in the survey, 468 were female undergraduate students who met the analysis criteria. Among them, 85 individuals fit the definition of “Long COVID” (18.16%).

Within the group of patients with long COVID, 69 individuals experienced changes in their overall menstrual patterns compared to the 6 months prior to contracting the novel coronavirus (81.18%). Additionally, 17 individuals opted for acupuncture treatment following the onset of COVID-19 (20.00%), which resulted in less impact on their menstrual cycle (41.18% vs 64.71% without receiving acupuncture, OR = 2.62), menstrual period duration (41.18% vs 64.71%, OR = 2.62), menstrual flow (47.06% vs 69.18%, OR = 2.52), and the color of menstrual blood (41.18% vs 63.24%, OR = 2.46) among these patients. Long COVID had a certain impact on menstruation.

Acupuncture potentially alleviates the clinical symptoms of long COVID and reduces its impact on women’s menstrual cycle, thus having potential therapeutic value in the treatment of long COVID.

Source: Dong J, Ni J, Zhang Z, Yan H, Xu J, Zhao J. The impact of “long COVID” on menstruation in Chinese female college students and the intervention of acupuncture. Medicine (Baltimore). 2024 Feb 9;103(6):e36818. doi: 10.1097/MD.0000000000036818. PMID: 38335408; PMCID: PMC10860984. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10860984/ (Full text)

Headache or Disturbed Smell and Taste During Acute COVID-19 as Predictors of Long COVID at One Year

Abstract:

Purpose: Long coronavirus disease (COVID) poses a significant health concern for a substantial proportion of COVID-19 patients. Viral pathogenesis studies suggest the potential of central nervous system (CNS) affection in the acute phase of COVID-19 predicting long COVID.

This study investigates whether acute COVID-19 symptoms, particularly headache and disturbed smell and taste, predict manifestations of long COVID.

Methods: This prospective cohort study included COVID-19 patients hospitalized between March 2020, and May 2021. One year after discharge, patients responded to a symptom questionnaire. Logistic regression analysis was used to determine the odds ratio (OR) for these outcomes.

Results: Of 288 eligible patients, 111 responded to the follow-up questionnaire. At 1 year follow-up, disturbed smell and taste during acute COVID-19 did not elevate the risk of long COVID. However, patients with acute headache demonstrated a tendency towards an elevated risk of CNS-related long COVID. Notably, this risk significantly increased in patients reporting dizziness (adjusted OR=4.20; 95% confidence interval (CI) 1.19 – 14.85). Neither disturbed smell and taste nor headache during acute COVID-19 indicated a statistically significant risk of worsening in fatigue, health, or total symptom score at 1-year follow-up.

Conclusion: Headache, and not disturbed smell and taste, predicted CNS-related long COVID. Further research is warranted to clarify pathways connecting CNS-related symptoms during acute COVID-19 with long COVID, aiding the efforts of addressing the range of symptoms observed among long COVID patients and developing effective interventions.

Source: Jane Agergaard. Headache or Disturbed Smell and Taste During Acute COVID-19 as Predictors of Long COVID at One Year, 07 February 2024, PREPRINT (Version 1) available at Research Square [https://doi.org/10.21203/rs.3.rs-3930891/v1] https://www.researchsquare.com/article/rs-3930891/v1 (Full text)

SSRI Use During Acute COVID-19 Infection Associated with Lower Risk of Long COVID Among Patients with Depression

Abstract:

Background Long COVID, also known as post-acute sequelae of COVID-19 (PASC), is a poorly understood condition with symptoms across a range of biological domains that often have debilitating consequences. Some have recently suggested that lingering SARS-CoV-2 virus in the gut may impede serotonin production and that low serotonin may drive many Long COVID symptoms across a range of biological systems. Therefore, selective serotonin reuptake inhibitors (SSRIs), which increase synaptic serotonin availability, may prevent or treat Long COVID. SSRIs are commonly prescribed for depression, therefore restricting a study sample to only include patients with depression can reduce the concern of confounding by indication.

Methods In an observational sample of electronic health records from patients in the National COVID Cohort Collaborative (N3C) with a COVID-19 diagnosis between September 1, 2021, and December 1, 2022, and pre-existing major depressive disorder, the leading indication for SSRI use, we evaluated the relationship between SSRI use at the time of COVID-19 infection and subsequent 12-month risk of Long COVID (defined by ICD-10 code U09.9). We defined SSRI use as a prescription for SSRI medication beginning at least 30 days before COVID-19 infection and not ending before COVID-19 infection. To minimize bias, we estimated the causal associations of interest using a nonparametric approach, targeted maximum likelihood estimation, to aggressively adjust for high-dimensional covariates.

Results We analyzed a sample (n = 506,903) of patients with a diagnosis of major depressive disorder before COVID-19 diagnosis, where 124,928 (25%) were using an SSRI. We found that SSRI users had a significantly lower risk of Long COVID compared to nonusers (adjusted causal relative risk 0.90, 95% CI (0.86, 0.94)).

Conclusion These findings suggest that SSRI use during COVID-19 infection may be protective against Long COVID, supporting the hypothesis that serotonin may be a key mechanistic biomarker of Long COVID.

Source: Zachary Butzin-DozierYunwen JiSarang DeshpandeEric HurwitzJeremy CoyleJunming (Seraphina) ShiAndrew MertensMark J. van der LaanJohn M. Colford Jr.Rena C. PatelAlan E. Hubbardthe National COVID Cohort Collaborative (N3C) Consortium. SSRI Use During Acute COVID-19 Infection Associated with Lower Risk of Long COVID Among Patients with Depression.  

Cluster Analysis to Identify Long COVID Phenotypes Using 129Xe Magnetic Resonance Imaging: A Multi-centre Evaluation

Abstract:

Background Long COVID impacts ∼10% of people diagnosed with COVID-19, yet the pathophysiology driving ongoing symptoms is poorly understood. We hypothesised that 129Xe magnetic resonance imaging (MRI) could identify unique pulmonary phenotypic subgroups of long COVID, therefore we evaluated ventilation and gas exchange measurements with cluster analysis to generate imaging-based phenotypes.

Methods COVID-negative controls and participants who previously tested positive for COVID-19 underwent 129XeMRI ∼14-months post-acute infection across three centres. Long COVID was defined as persistent dyspnea, chest tightness, cough, fatigue, nausea and/or loss of taste/smell at MRI; participants reporting no symptoms were considered fully-recovered. 129XeMRI ventilation defect percent (VDP) and membrane (Mem)/Gas, red blood cell (RBC)/Mem and RBC/Gas ratios were used in k-means clustering for long COVID, and measurements were compared using ANOVA with post-hoc Bonferroni correction.

Results We evaluated 135 participants across three centres: 28 COVID-negative (40±16yrs), 34 fully-recovered (42±14yrs) and 73 long COVID (49±13yrs). RBC/Mem (p=0.03) and FEV1 (p=0.04) were different between long- and COVID-negative; FEV1 and all other pulmonary function tests (PFTs) were within normal ranges. Four unique long COVID clusters were identified compared with recovered and COVID-negative. Cluster1 was the youngest with normal MRI and mild gas-trapping; Cluster2 was the oldest, characterised by reduced RBC/Mem but normal PFTs; Cluster3 had mildly increased Mem/Gas with normal PFTs; and Cluster4 had markedly increased Mem/Gas with concomitant reduction in RBC/Mem and restrictive PFT pattern.

Conclusion We identified four 129XeMRI long COVID phenotypes with distinct characteristics. 129XeMRI can dissect pathophysiologic heterogeneity of long COVID to enable personalised patient care.

Source: Rachel L EddyDavid MummyShuo ZhangHaoran DaiAryil BechtelAlexandra SchmidtBradie FrizzellFiroozeh V GerayeliJonathon A LeipsicJanice M LeungBastiaan DriehuysLoretta G QueMario CastroDon D SinPeter J Niedbalski. Cluster Analysis to Identify Long COVID Phenotypes Using 129Xe Magnetic Resonance Imaging: A Multi-centre Evaluation.