Category: Overlapping Illnesses

From aging to long COVID: exploring the convergence of immunosenescence, inflammaging, and autoimmunity

Abstract:

The process of aging is accompanied by a dynamic restructuring of the immune response, a phenomenon known as immunosenescence. This mini-review navigates through the complex landscape of age-associated immune changes, chronic inflammation, age-related autoimmune tendencies, and their potential links with immunopathology of Long COVID. Immunosenescence serves as an introductory departure point, elucidating alterations in immune cell profiles and their functional dynamics, changes in T-cell receptor signaling, cytokine network dysregulation, and compromised regulatory T-cell function.

Subsequent scrutiny of chronic inflammation, or “inflammaging,” highlights its roles in age-related autoimmune susceptibilities and its potential as a mediator of the immune perturbations observed in Long COVID patients. The introduction of epigenetic facets further amplifies the potential interconnections.

In this compact review, we consider the dynamic interactions between immunosenescence, inflammation, and autoimmunity. We aim to explore the multifaceted relationships that link these processes and shed light on the underlying mechanisms that drive their interconnectedness. With a focus on understanding the immunological changes in the context of aging, we seek to provide insights into how immunosenescence and inflammation contribute to the emergence and progression of autoimmune disorders in the elderly and may serve as potential mediator for Long COVID disturbances.

Source: Müller L, Di Benedetto S. From aging to long COVID: exploring the convergence of immunosenescence, inflammaging, and autoimmunity. Front Immunol. 2023 Oct 24;14:1298004. doi: 10.3389/fimmu.2023.1298004. PMID: 37942323; PMCID: PMC10628127. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10628127/ (Full text)

Predictive models of long COVID

Abstract:

Background: The cause and symptoms of long COVID are poorly understood. It is challenging to predict whether a given COVID-19 patient will develop long COVID in the future.

Methods: We used electronic health record (EHR) data from the National COVID Cohort Collaborative to predict the incidence of long COVID. We trained two machine learning (ML) models – logistic regression (LR) and random forest (RF). Features used to train predictors included symptoms and drugs ordered during acute infection, measures of COVID-19 treatment, pre-COVID comorbidities, and demographic information. We assigned the ‘long COVID’ label to patients diagnosed with the U09.9 ICD10-CM code. The cohorts included patients with (a) EHRs reported from data partners using U09.9 ICD10-CM code and (b) at least one EHR in each feature category. We analysed three cohorts: all patients (n = 2,190,579; diagnosed with long COVID = 17,036), inpatients (149,319; 3,295), and outpatients (2,041,260; 13,741).

Findings: LR and RF models yielded median AUROC of 0.76 and 0.75, respectively. Ablation study revealed that drugs had the highest influence on the prediction task. The SHAP method identified age, gender, cough, fatigue, albuterol, obesity, diabetes, and chronic lung disease as explanatory features. Models trained on data from one N3C partner and tested on data from the other partners had average AUROC of 0.75.

Interpretation: ML-based classification using EHR information from the acute infection period is effective in predicting long COVID. SHAP methods identified important features for prediction. Cross-site analysis demonstrated the generalizability of the proposed methodology.

Source: Antony B, Blau H, Casiraghi E, Loomba JJ, Callahan TJ, Laraway BJ, Wilkins KJ, Antonescu CC, Valentini G, Williams AE, Robinson PN, Reese JT, Murali TM; N3C consortium. Predictive models of long COVID. EBioMedicine. 2023 Oct;96:104777. doi: 10.1016/j.ebiom.2023.104777. Epub 2023 Sep 4. PMID: 37672869; PMCID: PMC10494314. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10494314/ (Full text)

Examining the relationship between inflammatory biomarkers during COVID-19 hospitalization and subsequent long-COVID symptoms: A longitudinal and retrospective study

Abstract:

Introduction: Long-COVID is a heterogeneous condition with a litany of physical and neuropsychiatric presentations and its pathophysiology remains unclear. Little is known about the association between inflammatory biomarkers, such as interleukin-6 (IL-6) and C-reactive protein (CRP) in the acute phase, and persistent symptoms after hospitalization in COVID-19 patients.

Methods: IL-6, CRP, troponin-T, and ferritin were analyzed at admission for all patients with COVID-19 between September 1, 2020 to January 10, 2021. Survivors were followed up 3-months following hospital discharge and were asked to report persistent symptoms they experienced. Admission data were retrospectively collected. Independent t-tests and Mann-Whitney U tests were performed.

Results: In a sample of 144 patients (62.5% male, mean Age 62 years [SD = 13.6]) followed up 3 months after hospital discharge, the commonest symptoms reported were fatigue (54.2%), breathlessness (52.8%), and sleep disturbance (37.5%). In this sample, admission levels of IL-6, CRP and ferritin were elevated. However, those reporting myalgia, low mood, and anxiety at follow-up had lower admission levels of IL-6 (34.9 vs. 52.0 pg/mL, p = .043), CRP (83 vs. 105 mg/L, p = .048), and ferritin (357 vs. 568 ug/L, p = .01) respectively, compared with those who did not report these symptoms. Multivariate regression analysis showed that these associations were confounded by gender, as female patients had significantly lower levels of IL-6 and ferritin on admission (29.5 vs. 56.1, p = .03 and 421.5 vs. 589, p = .001, respectively) and were more likely to report myalgia, low mood and anxiety, when compared to males.

Conclusions: Our data demonstrate that female patients present more often with lower levels of inflammatory biomarkers on admission which are subsequently associated with long-term post-COVID symptoms, such as myalgia and anxiety, in those discharged from hospital with severe COVID-19. Further research is needed into the role of serum biomarkers in post-COVID prognostication.

Source: Sykes DL, Van der Feltz-Cornelis CM, Holdsworth L, Hart SP, O’Halloran J, Holding S, Crooks MG. Examining the relationship between inflammatory biomarkers during COVID-19 hospitalization and subsequent long-COVID symptoms: A longitudinal and retrospective study. Immun Inflamm Dis. 2023 Oct;11(10):e1052. doi: 10.1002/iid3.1052. PMID: 37904690; PMCID: PMC10614127. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10614127/ (Full text)

Core outcome measurement instruments for use in clinical and research settings for adults with post-COVID-19 condition: an international Delphi consensus study

Abstract:

Post-COVID-19 condition (also known as long COVID) is a new, complex, and poorly understood disorder. A core outcome set (COS) for post-COVID-19 condition in adults has been developed and agreement is now required on the most appropriate measurement instruments for these core outcomes.

We conducted an international consensus study involving multidisciplinary experts and people with lived experience of long COVID. The study comprised a literature review to identify measurement instruments for the core outcomes, a three-round online modified Delphi process, and an online consensus meeting to generate a core outcome measurement set (COMS). 594 individuals from 58 countries participated.

The number of potential instruments for the 12 core outcomes was reduced from 319 to 19. Consensus was reached for inclusion of the modified Medical Research Council Dyspnoea Scale for respiratory outcomes. Measures for two relevant outcomes from a previously published COS for acute COVID-19 were also included: time until death, for survival, and the Recovery Scale for COVID-19, for recovery. Instruments were suggested for consideration for the remaining nine core outcomes: fatigue or exhaustion, pain, post-exertion symptoms, work or occupational and study changes, and cardiovascular, nervous system, cognitive, mental health, and physical outcomes; however, consensus was not achieved for instruments for these outcomes.

The recommended COMS and instruments for consideration provide a foundation for the evaluation of post-COVID-19 condition in adults, which should help to optimise clinical care and accelerate research worldwide. Further assessment of this COMS is warranted as new data emerge on existing and novel measurement instruments.

Source: Gorst SL, Seylanova N, Dodd SR, Harman NL, O’Hara M, Terwee CB, Williamson PR, Needham DM, Munblit D, Nicholson TR; PC-COS study group. Core outcome measurement instruments for use in clinical and research settings for adults with post-COVID-19 condition: an international Delphi consensus study. Lancet Respir Med. 2023 Nov 2:S2213-2600(23)00370-3. doi: 10.1016/S2213-2600(23)00370-3. Epub ahead of print. PMID: 37926103. https://www.thelancet.com/journals/lanres/article/PIIS2213-2600(23)00370-3/fulltext (Full text)

Hyperbaric Oxygen Treatment for Long COVID: From Molecular Mechanism to Clinical Practice

Abstract:

Long COVID symptoms typically occur within 3 months of an initial COVID-19 infection, last for more than 2 months, and cannot be explained by other diagnoses. The most common symptoms include fatigue, dyspnea, coughing, and cognitive impairment.

The mechanisms of long COVID are not fully understood, but several hypotheses have been put forth. These include coagulation and fibrosis pathway activation, inflammatory and autoimmune manifestations, persistent virus presence, and Epstein-Barr virus reactivation.

Hyperbaric oxygen therapy (HBOT) is a therapeutic method in which a person inhales 100% oxygen under pressure greater than that of the atmosphere. HBOT has some therapeutic effects, including improvement of microcirculation, inhibition of cytokine release leading to a reduction in inflammatory responses, inhibition of autoimmune responses, and promotion of neurological repair.

Several clinical trials have been carried out using HBOT to treat long COVID. The results suggest that HBOT helps to improve symptom severity, reduce symptom duration, and enhance patients’ quality of life. It is believed that HBOT is an effective option for patients with long COVID, which is worth actively promoting.

Source: Pan JQ, Tian ZM, Xue LB. Hyperbaric Oxygen Treatment for Long COVID: From Molecular Mechanism to Clinical Practice. Curr Med Sci. 2023 Nov 4. doi: 10.1007/s11596-023-2799-1. Epub ahead of print. PMID: 37924387. https://pubmed.ncbi.nlm.nih.gov/37924387/

Probing long COVID through a proteomic lens: a comprehensive two-year longitudinal cohort study of hospitalised survivors

Abstract:

Background: As a debilitating condition that can impact a whole spectrum of people and involve multi-organ systems, long COVID has aroused the most attention than ever. However, mechanisms of long COVID are not clearly understood, and underlying biomarkers that can affect the long-term consequences of COVID-19 are paramount to be identified.

Methods: Participants for the current study were from a cohort study of COVID-19 survivors discharged from hospital between Jan 7, and May 29, 2020. We profiled the proteomic of plasma samples from hospitalised COVID-19 survivors at 6-month, 1-year, and 2-year after symptom onset and age and sex matched healthy controls. Fold-change of >2 or <0.5, and false-discovery rate adjusted P value of 0.05 were used to filter differentially expressed proteins (DEPs). In-genuity pathway analysis was performed to explore the down-stream effects in the dataset of significantly up- or down-regulated proteins. Proteins were integrated with long-term consequences of COVID-19 survivors to explore potential biomarkers of long COVID.

Findings: The proteomic of 709 plasma samples from 181 COVID-19 survivors and 181 matched healthy controls was profiled. In both COVID-19 and control group, 114 (63%) were male. The results indicated four major recovery modes of biological processes. Pathways related to cell-matrix interactions and cytoskeletal remodeling and hypertrophic cardiomyopathy and dilated cardiomyopathy pathways recovered relatively earlier which was before 1-year after infection. Majority of immune response pathways, complement and coagulation cascade, and cholesterol metabolism returned to similar status of matched healthy controls later but before 2-year after infection. Fc receptor signaling pathway still did not return to status similar to healthy controls at 2-year follow-up. Pathways related to neuron generation and differentiation showed persistent suppression across 2-year after infection. Among 98 DEPs from the above pathways, evidence was found for association of 11 proteins with lung function recovery, with the associations consistent at two consecutive or all three follow-ups. These proteins were mainly enriched in complement and coagulation (COMP, PLG, SERPINE1, SRGN, COL1A1, FLNA, and APOE) and hypertrophic/dilated cardiomyopathy (TPM2, TPM1, and AGT) pathways. Two DEPs (APOA4 and LRP1) involved in both neuron and cholesterol pathways showed associations with smell disorder.

Interpretation: The study findings provided molecular insights into potential mechanism of long COVID, and put forward biomarkers for more precise intervention to reduce burden of long COVID.

Source: Gu X, Wang S, Zhang W, Li C, Guo L, Wang Z, Li H, Zhang H, Zhou Y, Liang W, Li H, Liu Y, Wang Y, Huang L, Dong T, Zhang D, Wong CCL, Cao B. Probing long COVID through a proteomic lens: a comprehensive two-year longitudinal cohort study of hospitalised survivors. EBioMedicine. 2023 Nov 2;98:104851. doi: 10.1016/j.ebiom.2023.104851. Epub ahead of print. PMID: 37924708. https://www.thelancet.com/journals/ebiom/article/PIIS2352-3964(23)00417-6/fulltext (Full text)

Post-acute sequelae of COVID-19 in solid organ transplant recipients

Abstract:

Background: Post-acute sequelae of coronavirus disease 2019 (COVID-19) (PASC), defined as prolonged symptoms following an episode of COVID-19, is not well-characterized in solid organ transplant recipients (SOTR). In this study, we aimed to assess the prevalence of PASC in SOTR, its descriptive characteristics, and associated risk factors.

Methods: We retrospectively identified SOTRs with acute COVID-19 between June 1, 2020 and April 15, 2022, and abstracted demographic and medical history, characteristics of acute COVID-19 illness, and COVID-19 vaccination status. We defined PASC as ongoing/new symptoms present at 6 weeks or longer following acute COVID-19 diagnosis.

Results: Among 208 SOTRs with acute COVID-19, 72 (35%) developed PASC. Common symptoms were respiratory symptoms (67%), headache (40%), and difficulty concentrating (10%). Severe acute COVID-19 disease and presence of respiratory symptoms were associated with higher odds of PASC in multivariable analyses, while receipt of at least one COVID-19 vaccination prior to transplantation was protective.

Conclusion: We found that PASC occurs in about a third of SOTRs with acute COVID-19 and has similar symptoms as described previously in immunocompetent hosts. Pre-transplant vaccination may be protective. Further prospective multicenter studies are needed.

Source: Sigler R, Covarrubias K, Chen B, Rubarth RB, Torosian K, Sanchez CR, Bharti A, DeGruttola V, Aslam S. Post-acute sequelae of COVID-19 in solid organ transplant recipients. Transpl Infect Dis. 2023 Nov 3:e14167. doi: 10.1111/tid.14167. Epub ahead of print. PMID: 37922371. https://onlinelibrary.wiley.com/doi/10.1111/tid.14167 (Full text available as PDF file)

From COVID-19 to long COVID; the forms of the neurological manifestations

Abstract:

Ever since the SARS-CoV-2 infection was declared a global pandemic in 2020, numerous multisystemic manifestations have been discovered. The COVID-19 is known to cause a wide spectrum of neurological symptoms like fatigue, headache, brain fog, stroke, smell and taste disorders, encephalopathy and neurodegenerative disorders. The neurological manifestations are more prevalent in the post-COVID syndrome or long COVID. The National Institute for Health and Care Excellence and WHO defined Ongoing Symptomatic COVID as 4-12 weeks post infection and post COVID-19 syndrome as persistence of symptoms beyond 12 weeks.

So far there are limited data available regarding the pathophysiology of neurological symptoms of prolonged COVID, although neuroinflammation and oxidative damage have been implicated. In this review article, we have highlighted the transition from COVID to long-term COVID, focusing the discussion particularly on neurological complications.

Source: Ahuja, Sana and Zaheer, Sufian (2023) “From COVID-19 to long COVID; the forms of the neurological manifestations,” Journal of Mind and Medical Sciences: Vol. 10: Iss. 2, Article 5.
DOI: https://doi.org/10.22543/2392-7674.1403
Download available at: https://scholar.valpo.edu/jmms/vol10/iss2/5

Treatment of 95 post-Covid patients with SSRIs

Abstract:

After Covid-19 infection, 12.5% develops post-Covid-syndrome (PCS). Symptoms indicate numerous affected organ systems. After a year, chronic fatigue, dysautonomia and neurological and neuropsychiatric complaints predominate. In this study, 95 PCS patients were treated with selective serotonin reuptake inhibitors (SSRIs). This study used an exploratory questionnaire and found that two-thirds of patients had a reasonably good to strong response on SSRIs, over a quarter of patients had moderate response, while 10% reported no response.

Overall, patients experienced substantial improved well-being. Brainfog and sensory overload decreased most, followed by chronic fatigue and dysautonomia. Outcomes were measured with three different measures that correlated strongly with each other. The response to SSRIs in PCS conditions was explained by seven possible neurobiological mechanisms based on recent literature on PCS integrated with already existing knowledge.

Important for understanding these mechanisms is the underlying biochemical interaction between various neurotransmitter systems and parts of the immune system, and their dysregulation in PCS. The main link appears to be with the metabolic kynurenine pathway (KP) which interacts extensively with the immune system. The KP uses the same precursor as serotonin: tryptophan. The KP is overactive in PCS which maintains inflammation and which causes a lack of tryptophan. Finally, potential avenues for future research to advance this line of clinical research are discussed.

Source: Rus CP, de Vries BEK, de Vries IEJ, Nutma I, Kooij JJS. Treatment of 95 post-Covid patients with SSRIs. Sci Rep. 2023 Nov 2;13(1):18599. doi: 10.1038/s41598-023-45072-9. PMID: 37919310; PMCID: PMC10622561. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10622561/ (Full text)

Characterization of neurocognitive deficits in patients with post-COVID-19 syndrome: persistence, patients’ complaints, and clinical predictors.

Abstract:

Introduction: Cognitive symptoms persisting beyond 3 months following COVID-19 present a considerable disease burden. We aimed to establish a domain-specific cognitive profile of post-COVID-19 syndrome (PCS). We examined the deficits’ persistence, relationships with subjective cognitive complaints, and clinical variables, to identify the most relevant cognitive deficits and their predictors.

Methods: This cross-sectional study examined cognitive performance and patient-reported and clinical predictors of cognitive deficits in PCS patients (n = 282) and socio-demographically comparable healthy controls (n = 52).

Results: On the Oxford Cognitive Screen-Plus, the patient group scored significantly lower in delayed verbal memory, attention, and executive functioning than the healthy group. In each affected domain, 10 to 20% of patients performed more than 1.5 SD below the control mean. Delayed memory was particularly affected, with a small effect of hospitalization and age. Attention scores were predicted by hospitalization and fatigue.

Discussion: Thus, PCS is associated with long-term cognitive dysfunction, particularly in delayed memory, attention, and executive functioning. Memory deficits seem to be of particular relevance to patients’ experience of subjective impairment. Hospitalization, fatigue, and age seem to predict cognitive deficits, while time since infection, depression, and pre-existing conditions do not.

Source: Kozik V, Reuken P, Utech I, Gramlich J, Stallmach Z, Demeyere N, Rakers F, Schwab M, Stallmach A, Finke K. Characterization of neurocognitive deficits in patients with post-COVID-19 syndrome: persistence, patients’ complaints, and clinical predictors. Front Psychol. 2023 Oct 17;14:1233144. doi: 10.3389/fpsyg.2023.1233144. PMID: 37915528; PMCID: PMC10616256. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10616256/ (Full text)