Long-COVID-19: the persisting imprint of SARS-CoV-2 infections on the innate immune system

In a recent Cell publication, Cheong et al. uncover how COVID-19 causes IL-6 induced epigenetic reprogramming of human immune stem cells, which causes lasting alterations in the composition and response characteristics of circulating immune cells.1 The study provides important insights into the mechanisms by which SARS-CoV-2 infections impact the human immune system and is an important hook into unraveling the mechanisms of post-acute sequelae of COVID-19 (PASC) commonly referred to as long-COVID.

While vaccination and drugs are reducing the societal impact of acute SARS-CoV-2 infections, between 10 and 40% of patients continue to suffer long after the acute infection has been cleared. The diverse PASC symptoms range from short breath and headaches to cognitive impairment (‘brain fog’) and debilitating fatigue. Not only are no treatments for PASC available but also the underlying molecular mechanisms remain opaque.2

Cheong et al. investigated in patients’ circulating immune cells if detectable changes persisted after clearance of the acute SARS-CoV-2 infection 3 weeks after the first symptoms. They assembled a cohort of COVID-19 convalescent patients, which was sampled between 1–3 and 4–12 months after SARS-CoV-2 infections requiring intensive care unit (ICU) admission and compared these patients to non-infected controls and to patients that had been on the ICU for different reasons. Focusing on peripheral blood mononuclear cells (PBMC) they investigated transcriptional or epigenetic changes using an integrated pipeline of single-nuclei transcriptome analysis and ATAC-seq sequencing, which identifies accessible chromatin regions. Among PBMCs CD14+ monocytes exhibited the most drastic changes. CD14+ monocytes are a group of heterogenous, short-lived antigen presenting cells that help orchestrating immune responses. Among these the authors could distinguish one cluster, M.SC3, which was more abundant even 12 months after the infection. Cells in this cluster resembled intermediate-type monocytes with functions that altogether resemble dendritic cells, the most effective amongst professional antigen presenting cells. In response to stimuli indicating viral infections, post-COVID monocytes showed up to 100-fold increased secretion of proinflammatory cytokines and enhanced transcriptional responses relating to cytokine signaling and monocyte activation. ATAC-seq also revealed a persistent pattern of differentially accessible chromatin which increased in abundance in early convalescent patients and did not return to the low levels observed in healthy individuals even 12 months after the acute infection. Thus, following severe SARS-CoV-2 infections, patients’ CD14+ monocytes carry specific and persistent epigenetic changes that puts them into an alerted state with heightened response characteristics.

Given that monocytes have a lifespan of a single day, the discovery of persistent epigenetic changes is notable and may reflect altered hematopoiesis and inheritance of epigenetic states from hematopoietic stem and progenitor cells (HSPC). To overcome the challenges associated with obtaining bone marrow resident HSPC, Cheong et al. developed a platform to enrich rare circulating HSPCs from PBMC and demonstrated that these faithfully represent the diversity and functional characteristics of their bone marrow-derived counterparts. With this platform, they discovered lasting epigenetic changes in HSPC of post-COVID patients that resembled those observed in mature monocytes. Especially late post-COVID HSPC exhibited skewed hematopoiesis with a significant increase of granulocyte monocyte precursor (GMP) cells. Intriguingly, the stem cells and the mature monocytes shared epigenetic signatures indicating that epigenetic and transcriptional programs are inherited by the mature progeny. The previously identified M.SC3 module activity was similarly increased in stem cells of the same patients.

Read the rest of this article HERE. 

Source: Boes, M., Falter-Braun, P. Long-COVID-19: the persisting imprint of SARS-CoV-2 infections on the innate immune system. Sig Transduct Target Ther 8, 460 (2023). https://doi.org/10.1038/s41392-023-01717-9 https://www.nature.com/articles/s41392-023-01717-9 (Full text)

Creatine supplementation combined with breathing exercises reduces respiratory discomfort and improves creatine status in patients with long-COVID

Abstract:

Eight long-COVID patients with moderate fatigue that had lasted for ≥3 months were recruited. All patients were allocated in a double-blind parallel-group design to receive either 4 g of creatine per day plus breathing exercises (study group) or breathing exercises only (control group) for 3 months.

Creatine induced a significant increase in tissue total creatine levels for all 14 locations evaluated in the present study (P < 0.05), while its levels significantly dropped in the right frontal gray matter and left parietal mesial gray matter at follow-up in the control group (P < 0.05).

No change in time to exhaustion was demonstrated in the control group (P > 0.05), while the mean time to exhaustion was significantly improved for 54 s in the study group post-administration (P = 0.05).

These preliminary findings suggest that creatine is as an effective adjuvant therapeutic to breathing exercises for tackling the clinical features in long-COVID.

Source: Slankamenac, J; Ranisavljev, M; Todorovic, N; Ostojic, J; Stajer, V; Ostojic, SM. Creatine supplementation combined with breathing exercises reduces respiratory discomfort and improves creatine status in patients with long-COVID. Journal of Postgraduate Medicine ():, December 07, 2023. | DOI: 10.4103/jpgm.jpgm_650_23  https://journals.lww.com/jopm/abstract/9000/creatine_supplementation_combined_with_breathing.99983.aspx (Full text available as PDF file)

Low handgrip strength is associated with worse functional outcomes in long-Covid

Abstract:

The diagnosis of long-Covid is troublesome, even when functional limitations are present. Dynapenia is a decrease in muscle strength and power production and may explain in part these limitations. This study aimed to identify the distribution and possible association of dynapenia with functional assessment in patients with long-Covid.

A total of 113 inpatients with COVID-19 were evaluated by functional assessment 120 days post-acute severe disease. Body composition, respiratory muscle strength, spirometry, six-minute walk test (6MWT) and hand-grip strength (HGS) were assessed.

Dynapenia was defined as HGS < 30kg/f (men), and < 20kg/f (women). Twenty-five (22%) participants were dynapenic, presenting lower muscle mass (p < 0.001), worse forced expiratory volume in the first second (FEV1) (p = 0.0001), lower forced vital capacity (p < 0.001), and inspiratory (p = 0.007) and expiratory (p = 0.002) peek pressures, as well as worse 6MWT performance (p < 0.001). Dynapenia was associated with worse FEV1, MEP, and 6MWT, independent of age (p < 0.001).

Patients with dynapenia had higher ICU admission rates (p = 0.01) and need for invasive mechanical ventilation (p = 0.007) during hospitalization. The HGS is a simple, reliable, and low-cost measurement that can be performed in outpatient clinics in low- and middle-income countries. Thus, HGS may be used as a proxy indicator of functional impairment in this population.

Source: Camila Miriam Suemi Sato Barros do Amaral AMARAL, Cássia da Luz Goulart GOULART, Bernardo Maia da Silva SILVA et al. Low handgrip strength is associated with worse functional outcomes in long-Covid, 11 December 2023, PREPRINT (Version 1) available at Research Square [https://doi.org/10.21203/rs.3.rs-3695556/v1] https://www.researchsquare.com/article/rs-3695556/v1 (Full text)

Prevalence of covid-19 and long covid in collegiate student athletes from spring 2020 to fall 2021: a retrospective survey

Abstract:

Background: Symptomatic COVID-19 and Long COVID, also referred to as post-acute sequelae of SARS-CoV-2 (PASC) or post-COVID conditions, have been widely reported in young, healthy people, but their prevalence has not yet been determined in student athletes. We sought to estimate the prevalence of reported COVID-19, symptomatic COVID-19, and Long COVID in college athletes in the United States attending 18 schools from spring 2020 to fall 2021.

Methods: We developed an online survey to measure the prevalence of student athletes who tested positive for COVID-19, developed Long COVID, and did not return to their sport during the relevant time period. We surveyed a convenience sample of 18 collegiate school administrators, representing about 7,000 student athletes. Of those schools surveyed, 16 responded regarding the spring 2020 semester, and 18 responded regarding the full academic year of fall 2020 to spring 2021 (both semesters).

Results: According to the survey responses, there were 9.8% of student athletes who tested positive for COVID-19 in spring 2020 and 25.4% who tested positive in the academic year of fall 2020 to spring 2021. About 4% of student athletes who tested positive from spring 2020 to spring 2021 developed Long COVID, defined as new, recurring, or ongoing physical or mental health consequences occurring 4 or more weeks after SARS-CoV-2 infection.

Conclusions: This study highlights that Long COVID occurs among young, healthy athletes and is a real consequence of COVID-19. Understanding the prevalence of Long COVID in this population requires longer follow-up and further study.

Source: Massey D, Saydah S, Adamson B, Lincoln A, Aukerman DF, Berke EM, Sikka R, Krumholz HM. Prevalence of covid-19 and long covid in collegiate student athletes from spring 2020 to fall 2021: a retrospective survey. BMC Infect Dis. 2023 Dec 13;23(1):876. doi: 10.1186/s12879-023-08801-z. PMID: 38093182; PMCID: PMC10717379. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10717379/ (Full text)

“None of us are lying”: an interpretive description of the search for legitimacy and the journey to access quality health services by individuals living with Long COVI

Abstract:

Background: Understanding of Long COVID has advanced through patient-led initiatives. However, research about barriers to accessing Long COVID services is limited. This study aimed to better understand the need for, access to, and quality of, Long COVID services. We explored health needs and experiences of services, including ability of services to address needs.

Methods: Our study was informed by the Levesque et al.’s (2013) “conceptual framework of access to health care.” We used Interpretive Description, a qualitative approach partly aimed at informing clinical decisions. We recruited participants across five settings. Participants engaged in one-time, semi-structured, virtual interviews. Interviews were transcribed verbatim. We used reflexive thematic analysis. Best practice to ensure methodological rigour was employed.

Results: Three key themes were generated from 56 interviews. The first theme illustrated the rollercoaster-like nature of participants’ Long COVID symptoms and the resulting impact on function and health. The second theme highlighted participants’ attempts to access Long COVID services. Guidance received from healthcare professionals and self-advocacy impacted initial access. When navigating Long COVID services within the broader system, participants encountered barriers to access around stigma; appointment logistics; testing and ‘normal’ results; and financial precarity and affordability of services. The third theme illuminated common factors participants liked and disliked about Long COVID services. We framed each sub-theme as the key lesson (stemming from all likes and dislikes) that, if acted upon, the health system can use to improve the quality of Long COVID services. This provides tangible ways to improve the system based directly on what we heard from participants.

Conclusion: With Long COVID services continuously evolving, our findings can inform decision makers within the health system to better understand the lived experiences of Long COVID and tailor services and policies appropriately.

Source: Brehon K, Miciak M, Hung P, Chen SP, Perreault K, Hudon A, Wieler M, Hunter S, Hoddinott L, Hall M, Churchill K, Brown DA, Brown CA, Bostick G, Skolnik K, Lam G, Weatherald J, Gross DP. “None of us are lying”: an interpretive description of the search for legitimacy and the journey to access quality health services by individuals living with Long COVID. BMC Health Serv Res. 2023 Dec 12;23(1):1396. doi: 10.1186/s12913-023-10288-y. PMID: 38087299; PMCID: PMC10714615. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10714615/ (Full text)

Characterization of subgroups of myalgic encephalomyelitis/chronic fatigue syndrome based on disease onset, symptoms and biomarkers

Abstract:

Myalgic encephalomyelitis, also called chronic fatigue syndrome (ME/CFS), is an acquired multisystem disease. The core symptoms include fatigue, exercise intolerance and pain as well as cognitive, autonomic and immunological manifestations. The diagnosis of ME/CFS is based on clinical criteria. Specific biomarkers do not currently exist, but studies suggest a role for soluble cluster of differentiation 26 (sCD26) and autoantibodies (AAK) against G protein-coupled receptors (GPCR). In many cases, the disease begins as a result of infections. 

The aim of this work was to determine the pathophysiological significance of potential biomarkers, assuming different development mechanisms in patients with infection-associated disease onset compared to those with other triggers. In a first study, sCD26, also called dipeptidyl peptidase-4 (DPP-4) due to its enzymatic activity, was analyzed and compared in the serum of 205 ME/CFS patients and 98 controls. This was followed by a comprehensive correlation analysis between sCD26 and clinical and laboratory parameters for ME/CFS patients, separated by type of disease onset. In addition, CD26 expression on lymphocyte subpopulations was determined for 12 patients and 12 controls. 

In another study, a correlation analysis was carried out between AAK against vasoregulatory GPCR and symptoms in 116 ME/CFS patients, separated by type of disease onset. It was shown that in ME/CFS patients with infection-associated disease onset, sCD26 correlated with numerous immunological and metabolic parameters, the changes of which have also been described in connection with DPP-4 inhibitors. In addition, there were inverse correlations with AAK against alpha1-adrenergic and M3-acetylcholine receptors. 

In this subgroup, the second study found correlations between numerous GPCR-AAK and the severity of fatigue, muscle pain and cognitive symptoms as well as greater functional impairment relevant to everyday life. None of these correlations were found in patients without infection-associated disease onset. 

Here, sCD26 correlated inversely with orthostatically induced heart rate increases and AAK against alpha- and beta-adrenergic receptors with the severity of orthostatic symptoms. Different correlation patterns between AAK against GPCR and symptoms allow us to assume that in patients with ME/CFS, an altered function of the AAK or its receptors or signaling pathways has occurred as a result of an infection. The association of sCD26 and GPCR-AAK also indicates the dysregulation of other parts of the immune system with potentially pathological consequences. The differences presented compared to patients with non-infectious genesis suggest two definable subgroups.

Source: Szklarski, Marvin. Characterization of subgroups of myalgic encephalomyelitis/chronic fatigue syndrome based on disease onset, symptoms and biomarkers. Charité – University Medicine Berlin, dissertation. https://refubium.fu-berlin.de/handle/fub188/40276

Association of circulating biomarkers with illness severity measures differentiates myalgic encephalomyelitis/chronic fatigue syndrome and post-COVID-19 condition: a prospective cohort study

Abstract:

Background: Accumulating evidence suggests that autonomic dysfunction and persistent systemic inflammation are common clinical features in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and long COVID. However, there is limited knowledge regarding their potential association with circulating biomarkers and illness severity status.

Methods: This prospective, cross-sectional, case-control cohort study aimed to distinguish between the two patient populations by using self-reported outcome measures and circulating biomarkers to assess endothelial function and systemic inflammation. Thirty-one individuals with ME/CFS, 23 individuals with long COVID, and 31 matched healthy subjects were included. Regression analysis was used to examine associations between self-reported outcome measures and circulating biomarkers in study participants. Classification across groups was based on principal component and discriminant analyses.

Results: Four ME/CFS patients (13%), 1 with long COVID (4%), and 1 healthy control (3%) presented postural orthostatic tachycardia syndrome (POTS) with the 10-min NASA lean test. Compared with healthy controls, ME/CFS and long COVID subjects showed higher levels of ET-1 (p < 0.05) and VCAM-1 (p < 0.001), and lower levels of nitrites (NOx assessed as NO2– + NO3–) (p < 0.01). ME/CFS patients also showed higher levels of serpin E1 (PAI-1) and E-selectin than did both long COVID and control subjects (p < 0.01 in all cases). Long COVID patients had lower TSP-1 levels than did ME/CFS patients and healthy controls (p < 0.001). As for inflammation biomarkers, both long COVID and ME/CFS subjects had higher levels of TNF-α than did healthy controls (p < 0.01 in both comparisons). Compared with controls, ME/CFS patients had higher levels of IL-1β (p < 0.001), IL-4 (p < 0.001), IL-6 (p < 0.01), IL-10 (p < 0.001), IP-10 (p < 0.05), and leptin (p < 0.001). Principal component analysis supported differentiation between groups based on self-reported outcome measures and endothelial and inflammatory biomarkers.

Conclusions: Our findings revealed that combining biomarkers of endothelial dysfunction and inflammation with outcome measures differentiate ME/CFS and Long COVID using robust discriminant analysis of principal components. Further research is needed to provide a more comprehensive characterization of these underlying pathomechanisms, which could be promising targets for therapeutic and preventive strategies in these conditions.

Source: Joan Carles Domingo, Federica Battistini, Begoña Cordobilla et al. Association of circulating biomarkers with illness severity measures differentiates myalgic encephalomyelitis/chronic fatigue syndrome and post-COVID-19 condition: a prospective cohort study, 16 December 2023, PREPRINT (Version 1) available at Research Square [https://doi.org/10.21203/rs.3.rs-3736031/v1] https://www.researchsquare.com/article/rs-3736031/v1 (Full text)

Post-acute COVID-19 complications in UK doctors: results of a cross-sectional survey

Abstract:

Background: As a consequence of their occupation, doctors and other healthcare workers were at higher risk of contracting coronavirus disease 2019 (COVID-19), and more likely to experience severe disease compared to the general population. However, systematic information on post-acute COVID complications in doctors is very limited.

Aims: This study aimed to determine the symptoms, perceived determinants, health and occupational impact, and consequent needs relating to post-acute COVID complications in UK doctors.

Methods: An online cross-sectional survey was distributed to UK doctors self-identifying as having Long COVID or other post-acute COVID complications.

Results: Of 795 responses, 603 fulfilled the inclusion criteria of being a UK-based medical doctor experiencing one or more post-acute COVID complications. Twenty-eight per cent reported a lack of adequate Respiratory Protective Equipment at the time of contracting COVID-19. Eighteen per cent of eligible respondents reported that they had been unable to return to work since acquiring COVID.

Conclusions: Post-acute COVID (Long COVID) in UK doctors is a substantial burden for respondents to our questionnaire. The results indicated that insufficient respiratory protection could have contributed to occupational disease, with COVID-19 being contracted in the workplace, and resultant post-COVID complications. Although it may be too late to address the perceived determinants of inadequate protection for those already suffering with Long COVID, more investment is needed in rehabilitation and support of those afflicted.

Source: D Bland, R Evans, A Binesmael, S Wood, S P Qureshi, K Fearnley, A Small, W D Strain, R Agius, Post-acute COVID-19 complications in UK doctors: results of a cross-sectional survey, Occupational Medicine, 2023;, kqad120, https://doi.org/10.1093/occmed/kqad120 https://academic.oup.com/occmed/advance-article-abstract/doi/10.1093/occmed/kqad120/7468904?redirectedFrom=fulltext

Effectiveness of Antiviral Therapy on Long COVID: A Systematic Review and Meta-Analysis

Abstract:

Antiviral treatment reduces the severity and mortality of SARS-CoV-2 infection; however, its effectiveness against long COVID-19 is unclear. This study aimed to evaluate the effectiveness of antiviral drugs in preventing long COVID and related hospitalizations/deaths. Scientific and medical databases were searched from 1 January 2020 to 30 June 2023. We included observational cohort studies comparing individuals receiving early antiviral therapy for COVID-19 and those receiving supportive treatment.
A fixed-effects model was used to merge the effects reported in two or more studies. The risk of post-acute sequelae of COVID-19 (PASC) was combined as an odds ratio (OR). Six studies were selected, including a total of 3,352,235 participants. The occurrence of PASC was 27.5% lower in patients who received antiviral drugs during the early stages of SARS-CoV-2 infection (OR = 0.725; 95% confidence interval [CI] = 0.409–0.747) than in the supportive treatment group. Moreover, the risk of PASC-associated hospitalization and mortality was 29.7% lower in patients receiving early antiviral therapy than in the supportive treatment group (OR = 0.721; 95% CI = 0.697–0.794).
Early antiviral therapy was associated with a reduced risk of PASC and related hospitalization or death. Thus, early antiviral therapy is recommended for at-risk individuals.
Source: Choi YJ, Seo YB, Seo J-W, Lee J, Nham E, Seong H, Yoon JG, Noh JY, Cheong HJ, Kim WJ, et al. Effectiveness of Antiviral Therapy on Long COVID: A Systematic Review and Meta-Analysis. Journal of Clinical Medicine. 2023; 12(23):7375. https://doi.org/10.3390/jcm12237375 https://www.mdpi.com/2077-0383/12/23/7375 (Full text)