Persistent Circulating Severe Acute Respiratory Syndrome Coronavirus 2 Spike Is Associated With Post-acute Coronavirus Disease 2019 Sequelae

SARS-CoV-2 S Protein Reduces Cytoprotective Defenses and Promotes Human Endothelial Cell Senescence

Premature vascular aging and endothelial cell senescence are major risk factors for cardiovascular diseases and atherothrombotic disturbances, which are main complications of both acute and long COVID-19. The S protein of SARS-CoV2, which acts as the receptor binding protein for the viral infection, is able to induce endothelial cells inflammation and it has been found as an isolated element in the circulation and in human tissues reservoirs months after infection. Here, we investigated whether the S protein is able to directly induce endothelial cell senescence and deciphered some of the mechanisms involved. In primary cultures of human umbilical vein endothelial cells (HUVEC), SARS-CoV-2 S protein enhanced in a concentration-dependent manner the cellular content of senescence and DNA damage response markers (senescence-associated-β galactosidase, γH2AX), as well as growth-arrest effectors (p53, p21, p16). In parallel, the S protein reduced the availability of cytoprotective proteins, such as the anti-aging protein klotho, Nrf2 or heme oxygenase-1, and caused functional harm by impairing ex vivo endothelial-dependent vasorelaxation in murine microvessels. These effects were prevented by the pharmacological inhibition of the NLRP3 inflammasome with MCC950. Furthermore, the supplementation with either recombinant klotho or angiotensin-(1-7), equally protected against the pro-senescence, pro-inflammatory and pro-oxidant action of the S protein. Globally, this study proposes novel mechanisms of disease in the context of COVID-19 and its vascular sequelae and provides pharmacological clues in order to prevent such complications.

Tissue-based T cell activation and viral RNA persist for up to 2 years after SARS-CoV-2 infection

The mechanisms of postacute medical conditions and unexplained symptoms after SARS-CoV-2 infection [Long Covid (LC)] are incompletely understood. There is growing evidence that viral persistence, immune dysregulation, and T cell dysfunction may play major roles. We performed whole-body positron emission tomography imaging in a well-characterized cohort of 24 participants at time points ranging from 27 to 910 days after acute SARS-CoV-2 infection using the radiopharmaceutical agent [18F]F-AraG, a selective tracer that allows for anatomical quantitation of activated T lymphocytes. Tracer uptake in the postacute COVID-19 group, which included those with and without continuing symptoms, was higher compared with prepandemic controls in many regions, including the brain stem, spinal cord, bone marrow, nasopharyngeal and hilar lymphoid tissue, cardiopulmonary tissues, and gut wall. T cell activation in the spinal cord and gut wall was associated with the presence of LC symptoms. In addition, tracer uptake in lung tissue was higher in those with persistent pulmonary symptoms specifically. Increased T cell activation in these tissues was also observed in many individuals without LC. Given the high [18F]F-AraG uptake detected in the gut, we obtained colorectal tissue for in situ hybridization of SARS-CoV-2 RNA and immunohistochemical studies in a subset of five participants with LC symptoms. We identified intracellular SARS-CoV-2 single-stranded spike protein-encoding RNA in rectosigmoid lamina propria tissue in all five participants and double-stranded spike protein-encoding RNA in three participants up to 676 days after initial COVID-19, suggesting that tissue viral persistence could be associated with long-term immunologic perturbations.

Neuroinflammation in post-acute sequelae of COVID-19 (PASC) as assessed by [11C]PBR28 PET correlates with vascular disease measures

The COVID-19 pandemic caused by SARS-CoV-2 has triggered a consequential public health crisis of post-acute sequelae of COVID-19 (PASC), sometimes referred to as long COVID. The mechanisms of the heterogeneous persistent symptoms and signs that comprise PASC are under investigation, and several studies have pointed to the central nervous and vascular systems as being potential sites of dysfunction. In the current study, we recruited individuals with PASC with diverse symptoms, and examined the relationship between neuroinflammation and circulating markers of vascular dysfunction. We used [11C]PBR28 PET neuroimaging, a marker of neuroinflammation, to compare 12 PASC individuals versus 43 normative healthy controls. We found significantly increased neuroinflammation in PASC versus controls across a wide swath of brain regions including midcingulate and anterior cingulate cortex, corpus callosum, thalamus, basal ganglia, and at the boundaries of ventricles. We also collected and analyzed peripheral blood plasma from the PASC individuals and found significant positive correlations between neuroinflammation and several circulating analytes related to vascular dysfunction. These results suggest that an interaction between neuroinflammation and vascular health may contribute to common symptoms of PASC.

Long COVID among US adults from a population-based study: Association with vaccination, cigarette smoking, and the modifying effect of chronic obstructive pulmonary disease (COPD)

OBJECTIVE

Post-COVID Conditions (or Long COVID) have been widely reported, but population-based studies exploring the relationship between its risk factors are lacking. We examined the associations between Long COVID, chronic obstructive pulmonary disease [COPD], vaccination status, and cigarette smoking. We also tested for the modifying effect of COPD status.

METHODS

Data from the 2022 US nationwide Behavioral Risk Factor Surveillance System (BRFSS) were analyzed. Our primary outcome was Long COVID (Yes/No) after a positive COVID-19 diagnosis. Predictor variables were COPD, coronary heart disease (CHD), diabetes, asthma, body mass index, cigarette smoking status, and number of COVID-19 vaccinations (0-4). Weighted multivariable logistic regression models were used and adjusted for sociodemographic factors. Regression models were used to explore the modifying effects of COPD status.

RESULTS

The weighted prevalence of Long COVID among survivors (N = 121,379) was 21.8% (95%CI: 21.4, 22.3), with tiredness/fatigue (26.2% [95%:25.1, 27.2]) as the most common symptom. Respondents with COPD (aOR: 1.71 [95%CI: 1.45, 2.02]), current daily smokers (aOR: 1.23 [95%CI:1.01, 1.49]), and former smokers (aOR: 1.24 [95%CI:1.12, 1.38]) (vs. never established smokers) had higher odds of Long COVID. However, respondents who had received three (aOR: 0.75 [95%CI:0.65, 0.85]) and four (aOR: 0.71 [95%CI:0.58, 0.86]) vaccine doses (vs. no vaccine) had lower odds of Long COVID. COPD had a modifying effect on the relationship between cigarette smoking and Long COVID (p-value: 0.013).

CONCLUSION

Our findings underscore a complex interaction between COPD, cigarette smoking, and Long COVID. Further, COVID-19 vaccination may be protective against Long COVID.

Post-acute and Chronic Kidney Function Outcomes of COVID-19 in Children and Adolescents: An EHR Cohort Study from the RECOVER Initiative

We investigated the risks of post-acute and chronic adverse kidney outcomes of SARS-CoV-2 infection in the pediatric population via a retrospective cohort study using data from the RECOVER program. We included 1,864,637 children and adolescents under 21 from 19 children's hospitals and health institutions in the US with at least six months of follow-up time between March 2020 and May 2023. We divided the patients into three strata: patients with pre-existing chronic kidney disease (CKD), patients with acute kidney injury (AKI) during the acute phase (within 28 days) of SARS-CoV-2 infection, and patients without pre-existing CKD or AKI. We defined a set of adverse kidney outcomes for each stratum and examined the outcomes within the post-acute and chronic phases after SARS-CoV-2 infection. In each stratum, compared with the non-infected group, patients with COVID-19 had a higher risk of adverse kidney outcomes. For patients without pre-existing CKD, there were increased risks of CKD stage 2+ (HR 1.20; 95% CI: 1.13-1.28) and CKD stage 3+ (HR 1.35; 95% CI: 1.15-1.59) during the post-acute phase (28 days to 365 days) after SARS-CoV-2 infection. Within the post-acute phase of SARS-CoV-2 infection, children and adolescents with pre-existing CKD and those who experienced AKI were at increased risk of progression to a composite outcome defined by at least 50% decline in estimated glomerular filtration rate (eGFR), eGFR <15 mL/min/1.73m2, End Stage Kidney Disease diagnosis, dialysis, or transplant.

Sex differences and immune correlates of Long COVID development, persistence, and resolution

Sex differences have been observed in acute COVID-19 and Long COVID (LC) outcomes, with greater disease severity and mortality during acute infection in males and a greater proportion of females developing LC. We hypothesized that sex-specific immune dysregulation contributes to the pathogenesis of LC. To investigate the immunologic underpinnings of LC development and persistence, we used single-cell transcriptomics, single-cell proteomics, and plasma proteomics on blood samples obtained during acute SARS-CoV-2 infection and at 3 and 12 months post-infection in a cohort of 45 patients who either developed LC or recovered. Several sex-specific immune pathways were associated with LC. Specifically, males who would develop LC at 3 months had widespread increases in TGF-β signaling during acute infection in proliferating NK cells. Females who would develop LC demonstrated increased expression of XIST, an RNA gene implicated in autoimmunity, and increased IL1 signaling in monocytes at 12 months post infection. Several immune features of LC were also conserved across sexes. Both males and females with LC had reduced co-stimulatory signaling from monocytes and broad upregulation of NF-κB transcription factors. In both sexes, those with persistent LC demonstrated increased LAG3, a marker of T cell exhaustion, reduced ETS1 transcription factor expression across lymphocyte subsets, and elevated intracellular IL-4 levels in T cell subsets, suggesting that ETS1 alterations may drive an aberrantly elevated Th2-like response in LC. Altogether, this study describes multiple innate and adaptive immune correlates of LC, some of which differ by sex, and offers insights toward the pursuit of tailored therapeutics.

Design, Synthesis, and Structure-Activity Relationships of Novel Peptide Derivatives of the Severe Acute Respiratory Syndrome-Coronavirus-2 Spike-Protein that Potently Inhibit Nicotinic Acetylcholine Receptors

The spike-protein of SARS-CoV-2 has a distinctive amino-acid sequence (682RRARS686) that forms a cleavage site for the enzyme furin. Strikingly, the structure of the spike-protein loop containing the furin cleavage site bears substantial similarity to neurotoxin peptides found in the venoms of certain snakes and marine cone snails. Leveraging this relationship, we designed and synthesized disulfide-constrained peptides with amino-acid sequences corresponding to the furin cleavage-sites of wild-type (B.1 variant) SARS-CoV-2 or the Alpha, Delta, and Omicron variants. Remarkably, some of these peptides potently inhibited α7 and α9α10 nicotinic acetylcholine receptors (nAChR) with nM affinity and showed SARS-CoV-2 variant and nAChR subtype-dependent potencies. Nuclear magnetic resonance spectroscopy and molecular dynamics were used to rationalize structure-activity relationships between peptides and their cognate receptors. These findings delineate nAChR subtypes that can serve as high-affinity spike-protein targets in tissues central to COVID-19 pathophysiology and identify ligands and target receptors to inform the development of novel SARS-CoV-2 therapeutics.

Challenges and opportunities in long COVID research

Long COVID (LC) is a condition in which patients do not fully recover from the initial SARS-CoV-2 infection but rather have persistent or new symptoms for months to years following the infection. Ongoing research efforts are investigating the pathophysiologic mechanisms of LC and exploring preventative and therapeutic treatment approaches for patients. As a burgeoning area of investigation, LC research can be structured to be more inclusive, innovative, and effective. In this perspective, we highlight opportunities for patient engagement and diverse research expertise, as well as the challenges of developing definitions and reproducible studies. Our intention is to provide a foundation for collaboration and progress in understanding the biomarkers and mechanisms driving LC.

Cognitive profile, neuroimaging and fluid biomarkers in post-acute COVID-19 syndrome

We aimed to characterize the cognitive profile of post-acute COVID-19 syndrome (PACS) patients with cognitive complaints, exploring the influence of biological and psychological factors. Participants with confirmed SARS-CoV-2 infection and cognitive complaints ≥ 8 weeks post-acute phase were included. A comprehensive neuropsychological battery (NPS) and health questionnaires were administered at inclusion and at 1, 3 and 6 months. Blood samples were collected at each visit, MRI scan at baseline and at 6 months, and, optionally, cerebrospinal fluid. Cognitive features were analyzed in relation to clinical, neuroimaging, and biochemical markers at inclusion and follow-up. Forty-nine participants, with a mean time from symptom onset of 10.4 months, showed attention-executive function (69%) and verbal memory (39%) impairment. Apathy (64%), moderate-severe anxiety (57%), and severe fatigue (35%) were prevalent. Visual memory (8%) correlated with total gray matter (GM) and subcortical GM volume. Neuronal damage and inflammation markers were within normal limits. Over time, cognitive test scores, depression, apathy, anxiety scores, MRI indexes, and fluid biomarkers remained stable, although fewer participants (50% vs. 75.5%; p = 0.012) exhibited abnormal cognitive evaluations at follow-up. Altered attention/executive and verbal memory, common in PACS, persisted in most subjects without association with structural abnormalities, elevated cytokines, or neuronal damage markers.

The interplay of aging, adipose tissue, and COVID-19: a potent alliance with implications for health

Obesity has emerged as a significant public health challenge. With the ongoing increase in life expectancy, the prevalence of obesity is steadily growing, particularly among older age demographics. The extension of life expectancy frequently results in additional years of vulnerability to chronic health issues associated with obesity in the elderly.The concept of SARS-CoV-2 directly infecting adipose tissue stems from the fact that both adipocytes and stromal vascular fraction cells express ACE2, the primary receptor facilitating SARS-CoV-2 entry. It is noteworthy that adipose tissue demonstrates ACE2 expression levels similar to those found in the lungs within the same individual. Additionally, ACE2 expression in the adipose tissue of obese individuals surpasses that in non-obese counterparts. Viral attachment to ACE2 has the potential to disturb the equilibrium of renin-angiotensin system homeostasis, leading to an exacerbated inflammatory response.Consequently, adipose tissue has been investigated as a potential site for active SARS-CoV-2 infection, suggesting its plausible role in virus persistence and contribution to both acute and long-term consequences associated with COVID-19.This review is dedicated to presenting current evidence concerning the presence of SARS-CoV-2 in the adipose tissue of elderly individuals infected with the virus. Both obesity and aging are circumstances that contribute to severe health challenges, heightening the risk of disease and mortality. We will particularly focus on examining the mechanisms implicated in the long-term consequences, with the intention of providing insights into potential strategies for mitigating the aftermath of the disease.

Detectable plasma severe acute respiratory syndrome coronavirus 2 spike antigen is associated with poor antibody response following third messenger RNA vaccination in kidney transplant recipients

BACKGROUND

Kidney transplant recipients (KTRs) generate lower antibody responses to messenger RNA (mRNA)-based severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination, yet precise mechanisms for this poor response remain uncertain. One potential contributor is suboptimal spike antigen (sAg) translation and expression owing to transplant immunosuppression, which might lead to insufficient exposure to develop humoral and/or cellular immune responses.

METHODS

Within a single-arm clinical trial, 65 KTRs underwent ultrasensitive plasma sAg testing before, and 3 and 14 days after, the third mRNA vaccine doses. Anti-SARS-CoV-2 spike antibodies (anti-receptor binding domain [anti-RBD]) were serially measured at 14 and 30 days post-vaccination. Associations between sAg detection and clinical factors were assessed. Day 30 anti-RBD titer was compared among those with versus without sAg expression using Wilcoxon rank sum testing.

RESULTS

Overall, 16 (25%) KTRs were sAg positive (sAg+) after vaccination, peaking at day 3. Clinical and laboratory factors were broadly similar in sAg(+) versus sAg(-) KTRs. sAg(+) status was significantly negatively associated with day 30 anti-RBD response, with median (interquartile range) 10.8 (<0.4-338.3) U/mL if sAg(+) versus 709 (10.5-2309.5) U/mL if sAg(-) (i.e., 66-fold lower; p = .01).

CONCLUSION

Inadequate plasma sAg does not likely drive poor antibody responses in KTRs, rather sAg detection implies insufficient immune response to rapidly clear vaccine antigen from blood. Other downstream mechanisms such as sAg trafficking and presentation should be explored.

Towards understanding post-COVID-19 condition: A systematic meta-analysis of transcriptomic alterations with sex-specific insights

BACKGROUND

Post COVID-19 Condition (PCC), characterized by lingering symptoms post-acute COVID-19, poses clinical challenges, highlighting the need to understand its underlying molecular mechanisms. This meta-analysis aims to shed light on the transcriptomic landscapes and sex-specific molecular dynamics intrinsic to PCC.

METHODS

A systematic review identified three studies suitable for comprehensive meta-analysis, encompassing 135 samples (57 PCC subjects and 78 recovered subjects). We performed meta-analysis on differential gene expression, a gene set enrichment analysis of Reactome pathways, and weighted gene co-expression network analysis (WGCNA). We performed a drug and disease enrichment analysis and also assessed sex-specific differences in expression patterns.

KEY FINDINGS

A clear difference was observed in the transcriptomic profiles of PCC subjects, with 530 differentially expressed genes (DEGs) identified. Enrichment analysis revealed that the altered pathways were predominantly implicated in cell cycle processes, immune dysregulation and histone modifications. Antioxidant compounds such as hesperitin were predominantly linked to the hub genes of the DEGs. Sex-specific analyses highlighted disparities in DEGs and altered pathways in male and female PCC patients, revealing a difference in the expression of ribosomal proteins. PCC in men was mostly linked to neuro-cardiovascular disorders, while women exhibited more diverse disorders, with a high index of respiratory conditions.

CONCLUSION

Our study reveals the intricate molecular processes underlying PCC, highlighting that the differences in molecular dynamics between males and females could be key to understanding and effectively managing the varied symptomatology of this condition.

Human umbilical cord-derived mesenchymal stem cell transplantation improves the long COVID

No effective treatments can ameliorate symptoms of long COVID patients. Our study assessed the safety and efficacy of human umbilical cord-derived mesenchymal stem cells (UC-MSCs) in the treatment of long COVID patients. Ten long COVID patients were enrolled and received intravenous infusions of UC-MSCs on Days 0, 7, and 14. Adverse events and clinical symptoms were recorded, and chest-high-resolution CT (HRCT) images and laboratory parameters were analyzed. During UC-MSCs treatment and follow-up, we did not observe serious adverse events, the symptoms of long COVID patients were significantly relieved in a short time, especially sleep difficulty, depression or anxiety, memory issues, and so forth, and the lung lesions were also repaired. The routine laboratory parameters did not exhibit any significant abnormalities following UC-MSCs transplantation (UMSCT). The proportion of regulatory T cells gradually increased, but it was not statistically significant until 12 months. The proportion of naive B cells was elevated, while memory B cells, class-switched B-cells, and nonswitched B-cells decreased at 1 month after infusion. Additionally, we observed a transient elevation in circulating interleukin (IL)-6 after UMSCT, while tumor necrosis factor (TNF)-α, IL-17A, and IL-10 showed no significant changes. The levels of circulating immunoglobulin (Ig) M increased significantly at month 2, while IgA increased significantly at month 6. Furthermore, the SARS-CoV-2 IgG levels remained consistently high in all patients at Month 6, and there was no significant decrease during the subsequent 12-month follow-up. UMSCT was safe and tolerable in long COVID patients. It showed potential in alleviating long COVID symptoms and improving interstitial lung lesions.

Novel ultrasound-guided supraclavicular stellate ganglion block

INTRODUCTION

Stellate ganglion block (SGB) provides diagnostic and therapeutic benefits in pain syndromes in the head, neck, and upper extremity, including complex regional pain syndrome Types I and II, Raynaud's disease, hyperhidrosis, arterial embolism in the region of the arm.

METHODS

We present a novel ultrasound-guided supraclavicular stellate ganglion block. Considering the existing anatomical structures of the targeted area.

RESULTS AND CONCLUSIONS

We hope that we can provide fewer complications and additional benefits with this new approach.

Nirmatrelvir-Ritonavir for Acute COVID-19 in Patients With Cardiovascular Disease and Postacute Sequelae of SARS-CoV-2 Infection

Background

There is limited evidence of association of nirmatrelvir-ritonavir (NMV-r) and incidence of postacute sequelae of SARS-CoV-2 infection (PASC) in patients with pre-existing cardiovascular disease (CVD).

Objectives

The objective of this study was to assess the association of NMV-r in nonhospitalized, vaccinated patients with pre-existing CVD and occurrence of PASC.

Methods

We conducted a retrospective cohort study utilizing the TriNetX research network, including vaccinated patients with pre-existing CVD who developed COVID-19 between December 2021 and December 2022. Two cohorts were created based on NMV-r administration within 5 days of diagnosis: NMV-r and non-NMV-r cohort. The main outcome was presence of PASC, assessed between 30 to 90 days and 90 to 180 days after index COVID-19 infection. After propensity score matching, both cohorts were compared using t-test and chi-square test for continuous and categorical variables, respectively.

Results

A total of 26,953 patients remained in each cohort after propensity score matching. Broadly defined PASC occurred in 6,925 patients (26%) in the NMV-r cohort vs 8,150 patients (30.6%) in the non-NMV-r cohort (OR: 0.80; 95% CI: 0.76-0.82; P < 0.001) from 30 to 90 days and in 6,692 patients (25.1%) as compared to 8,910 patients (33.5%) (OR: 0.25, 95% CI: 0.23-0.29; P < 0.001) from 90 to 180 days. Similarly, narrowly defined PASC occurred in 5,335 patients (20%) in the NMV-r cohort vs 6,271 patients (23.6%) in the non-NMV-r cohort between 30 and 90 days (OR: 0.81, 95% CI: 0.78-0.84, P < 0.001) and in 5,121 patients (19.2%) as compared to 6,964 patients (26.1%) (OR: 0.67, 95% CI: 0.64-0.70, P < 0.001) between 90 and 180 days.

Conclusions

NMV-r in nonhospitalized vaccinated patients with pre-existing CVD with COVID-19 was associated with a reduction in PASC and health care utilization.

Presence of SARS-CoV-2 RNA in COVID-19 survivors with post-COVID symptoms: a systematic review of the literature

INTRODUCTION

Viral persistence is one of the main hypotheses explaining the presence of post-COVID symptoms. This systematic review investigated the presence of SARS-CoV-2 RNA in plasma, stool, urine, and nasal/oral swab samples in individuals with post-COVID symptomatology.

CONTENT

MEDLINE, CINAHL, PubMed, EMBASE, Web of Science databases, as well as medRxiv/bioRxiv preprint servers were searched up to November 25th, 2023. Articles investigating the persistence of SARS-CoV-2 RNA in plasma, stool, urine or nasal/oral swab samples in patients with post-COVID symptoms were included. Methodological quality was assessed using the Newcastle-Ottawa Scale or Cochrane's Risk of Bias (Rob) tool.

SUMMARY

From 322 studies identified, six studies met all inclusion criteria. The sample included 678 COVID-19 survivors (52 % female, aged from 29 to 66 years). The methodological quality was moderate in 88 % of the studies (n=5/6). Three papers investigated the presence of SARS-CoV-2 RNA in plasma, three studies in nasal/oral swabs, two studies in stool samples, one in urine and one in saliva. The follow-up was shorter than two months (<60 days after) in 66 % of the studies (n=4/6). The prevalence of SARS-CoV-2 RNA ranged from 5 to 59 % in patients with post-COVID symptoms the first two months after infection, depending on the sample tested, however, SARS-CoV-2 RNA was also identified in COVID-19 survivors without post-COVID symptoms (one study).

OUTLOOK

Available evidence can suggest the presence of persistent SARS-CoV-2 RNA in post-COVID patients in the short term, although the biases within the studies do not permit us to make firm assumptions. The association between post-COVID symptoms and SARS-CoV-2 RNA in the samples tested is also conflicting. The lack of comparative group without post-COVID symptoms limits the generalizability of viral persistence in post-COVID-19 condition.

Current landscape of long COVID clinical trials

Long COVID was reported as a multi-systemic condition after the infection of SARS-CoV-2, and more than 65 million people are suffering from this disease. It has been noted that around 10% of severe SARS-CoV-2 infected individuals are suffering from the enduring effects of long COVID. The symptoms of long COVID have also been noted in several mild or asymptomatic SARS-CoV-2 infected individuals. While limited reports on clinical trials investigating new therapeutics for long COVID exist, there is an abundance of scattered information available regarding these trials. This review explores the extensive literature search, and complete clinical trial database search to map the current status of long COVID clinical trials worldwide. The study listed about 110 long COVID clinical trials. In addition to conducting extensive long COVID clinical trials, we have comprehensively presented an overview of the condition, its symptoms, notable manifestations, associated clinical trials, the unique challenges it poses, and our recommendations for addressing long COVID.

Blueprint of differentially expressed genes reveals the dynamic gene expression landscape and the gender biases in long COVID

BACKGROUND

Long COVID has appeared as a significant global health issue and is an extra burden to the healthcare system. It affects a considerable number of people throughout the globe. However, substantial research gaps have been noted in understanding the mechanism and genomic landscape during the long COVID infection. A study has aimed to identify the differentially expressed genes (DEGs) in long COVID patients to fill the gap.

METHODS

We used the RNA-seq GEO dataset acquired through the GPL20301 Illumina HiSeq 4000 platform. The dataset contains 36 human samples derived from PBMC (Peripheral blood mononuclear cells). Thirty-six human samples contain 13 non-long COVID individuals' samples and 23 long COVID individuals' samples, considered the first direction analysis. Here, we performed two-direction analyses. In the second direction analysis, we divided the dataset gender-wise into four groups: the non-long COVID male group, the long COVID male group, the non-long COVID female group, and the long COVID female group.

RESULTS

In the first analysis, we found no gene expression. In the second analysis, we identified 250 DEGs. During the DEG profile analysis of the non-long COVID male group and the long COVID male group, we found three upregulated genes: IGHG2, IGHG4, and MIR8071-2. Similarly, the analysis of the non-long COVID female group and the long COVID female group reveals eight top-ranking genes. It also indicates the gender biases of differentially expressed genes among long COVID individuals. We found several DEGs involved in PPI and co-expression network formation. Similarly, cluster enrichment and gene list enrichment analysis were performed, suggesting several genes are involved in different biological pathways or processes.

CONCLUSIONS

This study will help better understand the gene expression landscape in long COVID. However, it might help the discovery and development of therapeutics for long COVID.

Long COVID and post-acute sequelae of SARS-CoV-2 pathogenesis and treatment: A Keystone Symposia report

In 2023, the Keystone Symposia held the first international scientific conference convening research leaders investigating the pathology of post-acute sequelae of COVID-19 (PASC) or Long COVID, a growing and urgent public health priority. In this report, we present insights from the talks and workshops presented during this meeting and highlight key themes regarding what researchers have discovered regarding the underlying biology of PASC and directions toward future treatment. Several themes have emerged in the biology, with inflammation and other immune alterations being the most common focus, potentially related to viral persistence, latent virus reactivation, and/or tissue damage and dysfunction, especially of the endothelium, nervous system, and mitochondria. In order to develop safe and effective treatments for people with PASC, critical next steps should focus on the replication of major findings regarding potential mechanisms, disentangling pathogenic mechanisms from downstream effects, development of cellular and animal models, mechanism-focused randomized, placebo-controlled trials, and closer collaboration between people with lived experience, scientists, and other stakeholders. Ultimately, by learning from other post-infectious syndromes, the knowledge gained may help not only those with PASC/Long COVID, but also those with other post-infectious syndromes.

Trajectories of Inflammatory Markers and Post-COVID-19 Cognitive Symptoms: A Secondary Analysis of the CONTAIN COVID-19 Randomized Trial

BACKGROUND AND OBJECTIVES

Chronic systemic inflammation has been hypothesized to be a mechanistic factor leading to post-acute cognitive dysfunction after COVID-19. However, little data exist evaluating longitudinal inflammatory markers.

METHODS

We conducted a secondary analysis of data collected from the CONTAIN randomized trial of convalescent plasma in patients hospitalized for COVID-19, including patients who completed an 18-month assessment of cognitive symptoms and PROMIS Global Health questionnaires. Patients with pre-COVID-19 dementia/cognitive abnormalities were excluded. Trajectories of serum cytokine panels, D-dimer, fibrinogen, C-reactive peptide (CRP), ferritin, lactate dehydrogenase (LDH), and absolute neutrophil counts (ANCs) were evaluated over 18 months using repeated measures and Friedman nonparametric tests. The relationships between the area under the curve (AUC) for each inflammatory marker and 18-month cognitive and global health outcomes were assessed.

RESULTS

A total of 279 patients (N = 140 received plasma, N = 139 received placebo) were included. At 18 months, 76/279 (27%) reported cognitive abnormalities and 78/279 (28%) reported fair or poor overall health. PROMIS Global Mental and Physical Health T-scores were 0.5 standard deviations below normal in 24% and 51% of patients, respectively. Inflammatory marker levels declined significantly from hospitalization to 18 months for all markers (IL-2, IL-2R, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, IL-13, INFγ, TNFα, D-dimer, fibrinogen, ferritin, LDH, CRP, neutrophils; all p < 0.05), with the exception of IL-1β, which remained stable over time. There were no significant associations between the AUC for any inflammatory marker and 18-month cognitive symptoms, any neurologic symptom, or PROMIS Global Physical or Mental health T-scores. Receipt of convalescent plasma was not associated with any outcome measure.

DISCUSSION

At 18 months posthospitalization for COVID-19, cognitive abnormalities were reported in 27% of patients, and below average PROMIS Global Mental and Physical Health scores occurred in 24% and 51%, respectively. However, there were no associations with measured inflammatory markers, which decreased over time.

Persistence of SARS-CoV-2 colonization and high expression of inflammatory factors in cardiac tissue 6 months after COVID-19 recovery: a prospective cohort study

Background

The presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in myocardial autopsy tissues has been observed in certain individuals with coronavirus disease 2019 (COVID-19). However, the duration of cardiac involvement remains uncertain among recovered COVID-19 patients. Our study aims to evaluate the long-term persistence of SARS-CoV-2 within cardiac tissue.

Methods

We prospectively and consecutively evaluated the patients undergoing mitral valve replacement (MVR) and left atrial (LA) volume reduction surgery from May 25 to June 10, 2023 at our center, who had been approximately 6 months of recovery after Omicron wave. Patients tested positive for SARS-CoV-2 upon admission were excluded. The surgical LA tissue was collected in RNA preservation solution and stored at -80 ℃ immediately. Then SARS-CoV-2, interleukin-6 (IL-6) and interleukin-1β (IL-1β) RNA expression in LA tissues were assessed through thrice-repeated reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analyses. Categorical variables were assessed using the Chi-square or Fisher's exact tests, and continuous variables was analyzed using the Mann-Whitney U test.

Results

Nine of 41 patients were enrolled, all of whom tested negative for SARS-CoV-2 upon admission (two antigen and PCR tests). In four of nine patients, SARS-CoV-2 RNA was detected in their LA tissue, indicating viral colonization. Among the four positive cases, the IL-6 and IL-1β relative expression levels in the LA tissue of one patient were increased approximately 55- and 110-fold, respectively, compared to those of SARS-CoV-2 (-) patients. Increased expression of IL-6 and IL-1β were observed in the myocardium of this patient. Another patient demonstrated a remarkable 7-fold increase in both IL-6 and IL-1β expression, surpassing that of SARS-CoV-2 (-) patients. Additionally, no other cardiac inflammation-related diseases or conditions were presented in these two patients. The IL-6 and IL-1β expression levels of the remaining two patients were not significantly different from those of SARS-CoV-2 (-) patients. The relative expression levels of IL-6 and IL-1β in cardiac tissues of all SARS-CoV-2 (-) patients were relatively low. Interestingly, despite abnormally elevated levels of IL-6 and IL-1β within their cardiac tissue, two patients did not show a significant increase in serum IL-6 and IL-1β levels when compared to other patients.

Conclusions

Our research suggests that certain COVID-19-recovered patients have persistent colonization of SARS-CoV-2 in their cardiac tissue, accompanied by a local increase in inflammatory factors.

Back to the Basics of SARS-CoV-2 Biochemistry: Microvascular Occlusive Glycan Bindings Govern Its Morbidities and Inform Therapeutic Responses

Consistent with the biochemistry of coronaviruses as well established over decades, SARS-CoV-2 makes its initial attachment to host cells through the binding of its spike protein (SP) to sialylated glycans (containing the monosaccharide sialic acid) on the cell surface. The virus can then slide over and enter via ACE2. SARS-CoV-2 SP attaches particularly tightly to the trillions of red blood cells (RBCs), platelets and endothelial cells in the human body, each cell very densely coated with sialic acid surface molecules but having no ACE2 or minimal ACE2. These interlaced attachments trigger the blood cell aggregation, microvascular occlusion and vascular damage that underlie the hypoxia, blood clotting and related morbidities of severe COVID-19. Notably, the two human betacoronaviruses that express a sialic acid-cleaving enzyme are benign, while the other three-SARS, SARS-CoV-2 and MERS-are virulent. RBC aggregation experimentally induced in several animal species using an injected polysaccharide caused most of the same morbidities of severe COVID-19. This glycan biochemistry is key to disentangling controversies that have arisen over the efficacy of certain generic COVID-19 treatment agents and the safety of SP-based COVID-19 vaccines. More broadly, disregard for the active physiological role of RBCs yields unreliable or erroneous reporting of pharmacokinetic parameters as routinely obtained for most drugs and other bioactive agents using detection in plasma, with whole-blood levels being up to 30-fold higher. Appreciation of the active role of RBCs can elucidate the microvascular underpinnings of other health conditions, including cardiovascular disease, and therapeutic opportunities to address them.

The Aftermath of COVID-19: Exploring the Long-Term Effects on Organ Systems

BACKGROUND

Post-acute sequelae of SARS-CoV-2 infection (PASC) is a complicated disease that affects millions of people all over the world. Previous studies have shown that PASC impacts 10% of SARS-CoV-2 infected patients of which 50-70% are hospitalised. It has also been shown that 10-12% of those vaccinated against COVID-19 were affected by PASC and its complications. The severity and the later development of PASC symptoms are positively associated with the early intensity of the infection.

RESULTS

The generated health complications caused by PASC involve a vast variety of organ systems. Patients affected by PASC have been diagnosed with neuropsychiatric and neurological symptoms. The cardiovascular system also has been involved and several diseases such as myocarditis, pericarditis, and coronary artery diseases were reported. Chronic hematological problems such as thrombotic endothelialitis and hypercoagulability were described as conditions that could increase the risk of clotting disorders and coagulopathy in PASC patients. Chest pain, breathlessness, and cough in PASC patients were associated with the respiratory system in long-COVID causing respiratory distress syndrome. The observed immune complications were notable, involving several diseases. The renal system also was impacted, which resulted in raising the risk of diseases such as thrombotic issues, fibrosis, and sepsis. Endocrine gland malfunction can lead to diabetes, thyroiditis, and male infertility. Symptoms such as diarrhea, nausea, loss of appetite, and taste were also among reported observations due to several gastrointestinal disorders. Skin abnormalities might be an indication of infection and long-term implications such as persistent cutaneous complaints linked to PASC.

CONCLUSIONS

Long-COVID is a multidimensional syndrome with considerable public health implications, affecting several physiological systems and demanding thorough medical therapy, and more study to address its underlying causes and long-term effects is needed.

Precision Phenotyping for Curating Research Cohorts of Patients with Post-Acute Sequelae of COVID-19 (PASC) as a Diagnosis of Exclusion

Scalable identification of patients with the post-acute sequelae of COVID-19 (PASC) is challenging due to a lack of reproducible precision phenotyping algorithms and the suboptimal accuracy, demographic biases, and underestimation of the PASC diagnosis code (ICD-10 U09.9). In a retrospective case-control study, we developed a precision phenotyping algorithm for identifying research cohorts of PASC patients, defined as a diagnosis of exclusion. We used longitudinal electronic health records (EHR) data from over 295 thousand patients from 14 hospitals and 20 community health centers in Massachusetts. The algorithm employs an attention mechanism to exclude sequelae that prior conditions can explain. We performed independent chart reviews to tune and validate our precision phenotyping algorithm. Our PASC phenotyping algorithm improves precision and prevalence estimation and reduces bias in identifying Long COVID patients compared to the U09.9 diagnosis code. Our algorithm identified a PASC research cohort of over 24 thousand patients (compared to about 6 thousand when using the U09.9 diagnosis code), with a 79.9 percent precision (compared to 77.8 percent from the U09.9 diagnosis code). Our estimated prevalence of PASC was 22.8 percent, which is close to the national estimates for the region. We also provide an in-depth analysis outlining the clinical attributes, encompassing identified lingering effects by organ, comorbidity profiles, and temporal differences in the risk of PASC. The PASC phenotyping method presented in this study boasts superior precision, accurately gauges the prevalence of PASC without underestimating it, and exhibits less bias in pinpointing Long COVID patients. The PASC cohort derived from our algorithm will serve as a springboard for delving into Long COVID's genetic, metabolomic, and clinical intricacies, surmounting the constraints of recent PASC cohort studies, which were hampered by their limited size and available outcome data.

[Clinical and morphological features of lung injury long-term after SARS-CoV-2 recovery]

AIM

To study the clinical and histological profile of lung tissue in patients with persistent pulmonary disease, respiratory symptoms and CT findings after SARS-CoV-2 infection.

MATERIALS AND METHODS

The study included 15 patients (7 females and 8 males) with a mean age of 57.7 years. All patients underwent laboratory tests, chest computed tomography, echocardiography, and pulmonary function tests. Pulmonary tissue and bronchoalveolar lavage samples were obtained by fibrobronchoscopy, transbronchial forceps (2 patients), and lung cryobiopsy (11 patients); open biopsy was performed in 2 patients. Cellular composition, herpesvirus DNA, SARS-CoV-2, Mycobacterium tuberculosis complex, galactomannan optical density index, and bacterial and fungal microflora growth were determined in bronchoalveolar lavage. SARS-CoV-2 was also identified in samples from the nasal mucosa, throat and feces using a polymerase chain reaction.

RESULTS

The results showed no true pulmonary fibrosis in patients recovered from SARS-CoV-2 infection with persistent respiratory symptoms, functional impairment, and CT findings after SARS-CoV-2 infection. The observed changes comply with the current and/or resolving infection and inflammatory process.

CONCLUSION

Thus, no true pulmonary fibrosis was found in patients after SARS-CoV-2 infection with persistent respiratory symptoms, functional impairment, and CT findings. The observed changes comply with the current and/or resolving infection and inflammatory process.

A narrow ratio of nucleic acid to SARS-CoV-2 N-protein enables phase separation

SARS-CoV-2 Nucleocapsid protein (N) is a viral structural protein that packages the 30kb genomic RNA inside virions and forms condensates within infected cells through liquid-liquid phase separation (LLPS). N, in both soluble and condensed forms, has accessory roles in the viral life cycle including genome replication and immunosuppression. The ability to perform these tasks depends on phase separation and its reversibility. The conditions that stabilize and destabilize N condensates and the role of N-N interactions are poorly understood. We have investigated LLPS formation and dissolution in a minimalist system comprised of N protein and an ssDNA oligomer just long enough to support assembly. The short oligo allows us to focus on the role of N-N interaction. We have developed a sensitive FRET assay to interrogate LLPS assembly reactions from the perspective of the oligonucleotide. We find that N alone can form oligomers but that oligonucleotide enables their assembly into a three-dimensional phase. At a ~1:1 ratio of N to oligonucleotide LLPS formation is maximal. We find that a modest excess of N or of nucleic acid causes the LLPS to break down catastrophically. Under the conditions examined here assembly has a critical concentration of about 1 μM. The responsiveness of N condensates to their environment may have biological consequences. A better understanding of how nucleic acid modulates N-N association will shed light on condensate activity and could inform antiviral strategies targeting LLPS.

Serological markers and long COVID-A rapid systematic review

BACKGROUND

Long COVID is highly heterogeneous, often debilitating, and may last for years after infection. The aetiology of long COVID remains uncertain. Examination of potential serological markers of long COVID, accounting for clinical covariates, may yield emergent pathophysiological insights.

METHODS

In adherence to PRISMA guidelines, we carried out a rapid review of the literature. We searched Medline and Embase for primary observational studies that compared IgG response in individuals who experienced COVID-19 symptoms persisting ≥12 weeks post-infection with those who did not. We examined relationships between serological markers and long COVID status and investigated sources of inter-study variability, such as severity of acute illness, long COVID symptoms assessed and target antigen(s).

RESULTS

Of 8018 unique records, we identified 29 as being eligible for inclusion in synthesis. Definitions of long COVID varied. In studies that reported anti-nucleocapsid (N) IgG (n = 10 studies; n = 989 participants in aggregate), full or partial anti-Spike IgG (i.e. the whole trimer, S1 or S2 subgroups, or receptor binding domain, n = 19 studies; n = 2606 participants), or neutralizing response (n = 7 studies; n = 1123 participants), we did not find strong evidence to support any difference in serological markers between groups with and without persisting symptoms. However, most studies did not account for severity or level of care required during acute illness, and other potential confounders.

CONCLUSIONS

Pooling of studies would enable more robust exploration of clinical and serological predictors among diverse populations. However, substantial inter-study variations hamper comparability. Standardized reporting practices would improve the quality, consistency and comprehension of study findings.

COVID-19 and Long-COVID Thrombosis: From Clinical and Basic Science to Therapeutics

Coronavirus infectious disease-19 (COVID-19) is a pandemic characterized by serious lung disease and thrombotic events in the venous and circulation trees, which represent a harmful clinical sign of poor outcome. Thrombotic events are more frequent in patients with severe disease requiring intensive care units and are associated with platelet and clotting activation. However, after resolution of acute infection, patients may still have clinical sequelae, the so-called long-COVID-19, including thrombotic events again in the venous and arterial circulation. The mechanisms accounting for thrombosis in acute and long COVID-19 have not been fully clarified; interactions of COVID-19 with angiotensin converting enzyme 2 or toll-like receptor family or infection-induced cytokine storm have been suggested to be implicated in endothelial cells, leucocytes, and platelets to elicit clotting activation in acute as well in chronic phase of the disease. In acute COVID-19, prophylactic or full doses of anticoagulants exert beneficial effects even if the dosage choice is still under investigation; however, a residual risk still remains suggesting a need for a more appropriate therapeutic approach. In long COVID-19 preliminary data provided useful information in terms of antiplatelet treatment but definition of candidates for thrombotic prophylaxis is still undefined.

Large-scale phenotyping of patients with long COVID post-hospitalization reveals mechanistic subtypes of disease

One in ten severe acute respiratory syndrome coronavirus 2 infections result in prolonged symptoms termed long coronavirus disease (COVID), yet disease phenotypes and mechanisms are poorly understood1. Here we profiled 368 plasma proteins in 657 participants ≥3 months following hospitalization. Of these, 426 had at least one long COVID symptom and 233 had fully recovered. Elevated markers of myeloid inflammation and complement activation were associated with long COVID. IL-1R2, MATN2 and COLEC12 were associated with cardiorespiratory symptoms, fatigue and anxiety/depression; MATN2, CSF3 and C1QA were elevated in gastrointestinal symptoms and C1QA was elevated in cognitive impairment. Additional markers of alterations in nerve tissue repair (SPON-1 and NFASC) were elevated in those with cognitive impairment and SCG3, suggestive of brain-gut axis disturbance, was elevated in gastrointestinal symptoms. Severe acute respiratory syndrome coronavirus 2-specific immunoglobulin G (IgG) was persistently elevated in some individuals with long COVID, but virus was not detected in sputum. Analysis of inflammatory markers in nasal fluids showed no association with symptoms. Our study aimed to understand inflammatory processes that underlie long COVID and was not designed for biomarker discovery. Our findings suggest that specific inflammatory pathways related to tissue damage are implicated in subtypes of long COVID, which might be targeted in future therapeutic trials.

Mast cells in the autonomic nervous system and potential role in disorders with dysautonomia and neuroinflammation

Mast cells (MC) are ubiquitous in the body, and they are critical for not only in allergic diseases but also in immunity and inflammation, including having potential involvement in the pathophysiology of dysautonomias and neuroinflammatory disorders. MC are located perivascularly close to nerve endings and sites such as the carotid bodies, heart, hypothalamus, the pineal gland, and the adrenal gland that would allow them not only to regulate but also to be affected by the autonomic nervous system (ANS). MC are stimulated not only by allergens but also many other triggers including some from the ANS that can affect MC release of neurosensitizing, proinflammatory, and vasoactive mediators. Hence, MC may be able to regulate homeostatic functions that seem to be dysfunctional in many conditions, such as postural orthostatic tachycardia syndrome, autism spectrum disorder, myalgic encephalomyelitis/chronic fatigue syndrome, and Long-COVID syndrome. The evidence indicates that there is a possible association between these conditions and diseases associated with MC activation. There is no effective treatment for any form of these conditions other than minimizing symptoms. Given the many ways MC could be activated and the numerous mediators released, it would be important to develop ways to inhibit stimulation of MC and the release of ANS-relevant mediators.

Preexisting Psychiatric Conditions as Risk Factors for Diagnosed Long COVID-19 Syndrome Within Aggregated Electronic Health Record Data

OBJECTIVE

This study aimed to investigate the frequency of long COVID diagnosis among patients infected with severe acute respiratory syndrome coronavirus 2 with preexisting psychiatric conditions versus those without preexisting psychiatric conditions.

METHODS

The TriNetX Analytics platform, an aggregated electronic health record research network containing the deidentified electronic health record data of more than 90 million patients, was queried for patients who were diagnosed with COVID-19 infection based on International Classifications of Disease, Tenth Revision codes. Patients were stratified based on their preexisting psychiatric conditions, and new diagnoses of long COVID were recorded and reported as the primary outcome.

RESULTS

Among 1,180,948 patients previously diagnosed with COVID-19, 17,990 patients (1.52%) were diagnosed with long COVID based on the newly implemented International Classifications of Disease, Tenth Revision code "U09: post-COVID-19 condition." After propensity score matching, patients with any preexisting psychiatric diagnosis had a 1.52 (95% confidence interval [CI] = 1.47-1.58) times greater prevalence of diagnosed long COVID within 180 days of infection than patients without preexisting psychiatric diagnoses. Patients with diagnosed anxiety disorders (relative risk [RR] = 1.64; 95% CI = 1.57-1.71), mood disorders (RR = 1.65; 95% CI = 1.57-1.72), bipolar disorder (RR = 1.37; 95% CI = 1.21-1.54), major depressive disorder (RR = 1.69; 95% CI = 1.56-1.83), psychotic disorders (RR = 1.23; 95% CI = 1.06-1.44), and substance use disorders (RR = 1.28; 95% CI = 1.22-1.36) had higher risks for long COVID diagnoses when compared with patients without preexisting psychiatric illness at the time of diagnosis.

CONCLUSIONS

Multiple preexisting psychiatric diagnoses are associated with an increased risk of being diagnosed with long COVID after COVID-19 infection.

Precision nutrition to reset virus-induced human metabolic reprogramming and dysregulation (HMRD) in long-COVID

SARS-CoV-2, the etiological agent of COVID-19, is devoid of any metabolic capacity; therefore, it is critical for the viral pathogen to hijack host cellular metabolic machinery for its replication and propagation. This single-stranded RNA virus with a 29.9 kb genome encodes 14 open reading frames (ORFs) and initiates a plethora of virus-host protein-protein interactions in the human body. These extensive viral protein interactions with host-specific cellular targets could trigger severe human metabolic reprogramming/dysregulation (HMRD), a rewiring of sugar-, amino acid-, lipid-, and nucleotide-metabolism(s), as well as altered or impaired bioenergetics, immune dysfunction, and redox imbalance in the body. In the infectious process, the viral pathogen hijacks two major human receptors, angiotensin-converting enzyme (ACE)-2 and/or neuropilin (NRP)-1, for initial adhesion to cell surface; then utilizes two major host proteases, TMPRSS2 and/or furin, to gain cellular entry; and finally employs an endosomal enzyme, cathepsin L (CTSL) for fusogenic release of its viral genome. The virus-induced HMRD results in 5 possible infectious outcomes: asymptomatic, mild, moderate, severe to fatal episodes; while the symptomatic acute COVID-19 condition could manifest into 3 clinical phases: (i) hypoxia and hypoxemia (Warburg effect), (ii) hyperferritinemia ('cytokine storm'), and (iii) thrombocytosis (coagulopathy). The mean incubation period for COVID-19 onset was estimated to be 5.1 days, and most cases develop symptoms after 14 days. The mean viral clearance times were 24, 30, and 39 days for acute, severe, and ICU-admitted COVID-19 patients, respectively. However, about 25-70% of virus-free COVID-19 survivors continue to sustain virus-induced HMRD and exhibit a wide range of symptoms that are persistent, exacerbated, or new 'onset' clinical incidents, collectively termed as post-acute sequelae of COVID-19 (PASC) or long COVID. PASC patients experience several debilitating clinical condition(s) with >200 different and overlapping symptoms that may last for weeks to months. Chronic PASC is a cumulative outcome of at least 10 different HMRD-related pathophysiological mechanisms involving both virus-derived virulence factors and a multitude of innate host responses. Based on HMRD and virus-free clinical impairments of different human organs/systems, PASC patients can be categorized into 4 different clusters or sub-phenotypes: sub-phenotype-1 (33.8%) with cardiac and renal manifestations; sub-phenotype-2 (32.8%) with respiratory, sleep and anxiety disorders; sub-phenotype-3 (23.4%) with skeleto-muscular and nervous disorders; and sub-phenotype-4 (10.1%) with digestive and pulmonary dysfunctions. This narrative review elucidates the effects of viral hijack on host cellular machinery during SARS-CoV-2 infection, ensuing detrimental effect(s) of virus-induced HMRD on human metabolism, consequential symptomatic clinical implications, and damage to multiple organ systems; as well as chronic pathophysiological sequelae in virus-free PASC patients. We have also provided a few evidence-based, human randomized controlled trial (RCT)-tested, precision nutrients to reset HMRD for health recovery of PASC patients.

Bulk RNA sequencing for analysis of post COVID-19 condition in adolescents and young adults

BACKGROUND

Post COVID-19 condition (PCC) is a complication of SARS-COV-2 infection and can lead to long-term disability.

METHODS

The present study was designed to analyse the gene expression patterns of PCC through bulk RNA sequencing of whole blood and to explore the potential molecular mechanisms of PCC. Whole blood was collected from 80 participants enrolled in a prospective cohort study following SARS-CoV-2 infected and non-infected individuals for 6 months after recruitment and was used for bulk RNA sequencing. Identification of differentially expressed genes (DEG), pathway enrichment and immune cell deconvolution was performed to explore potential biological pathways involved in PCC.

RESULTS

We have found 13 differentially expressed genes associated with PCC. Enriched pathways were related to interferon-signalling and anti-viral immune processes.

CONCLUSION

The PCC transcriptome is characterized by a modest overexpression of interferon-stimulated genes, pointing to a subtle ongoing inflammatory response.

Murine alveolar macrophages rapidly accumulate intranasally administered SARS-CoV-2 Spike protein leading to neutrophil recruitment and damage

The trimeric SARS-CoV-2 Spike protein mediates viral attachment facilitating cell entry. Most COVID-19 vaccines direct mammalian cells to express the Spike protein or deliver it directly via inoculation to engender a protective immune response. The trafficking and cellular tropism of the Spike protein in vivo and its impact on immune cells remains incompletely elucidated. In this study, we inoculated mice intranasally, intravenously, and subcutaneously with fluorescently labeled recombinant SARS-CoV-2 Spike protein. Using flow cytometry and imaging techniques, we analyzed its localization, immune cell tropism, and acute functional impact. Intranasal administration led to rapid lung alveolar macrophage uptake, pulmonary vascular leakage, and neutrophil recruitment and damage. When injected near the inguinal lymph node medullary, but not subcapsular macrophages, captured the protein, while scrotal injection recruited and fragmented neutrophils. Widespread endothelial and liver Kupffer cell uptake followed intravenous administration. Human peripheral blood cells B cells, neutrophils, monocytes, and myeloid dendritic cells all efficiently bound Spike protein. Exposure to the Spike protein enhanced neutrophil NETosis and augmented human macrophage TNF-α (tumor necrosis factor-α) and IL-6 production. Human and murine immune cells employed C-type lectin receptors and Siglecs to help capture the Spike protein. This study highlights the potential toxicity of the SARS-CoV-2 Spike protein for mammalian cells and illustrates the central role for alveolar macrophage in pathogenic protein uptake.

Patients with Long COVID continue to experience significant symptoms at 12 months and factors associated with improvement: A prospective cohort study in France (PERSICOR)

OBJECTIVES

This study examines long COVID symptoms course over 12 months, their impact on daily life, and associated factors for symptom relief.

METHODS

A prospective cohort study included 231 participants with long COVID at 12-month follow-up. Data on characteristics, symptom course, and remission were collected using a questionnaire and a remission scale. Poisson regression models were used to estimate the prevalence rate ratio (PRR) and 95% confidence intervals (CIs) for factors associated with symptom improvement.

RESULTS

Of the 231 participants, 63.2% developed SARS-CoV-2 antibodies before COVID-19 vaccination. At 12 months, only 8.7% (95% CI: 5.4-13.1%) reported complete remission, while 28.6% noted significant improvement. Most symptoms remained prevalent: asthenia (83.1%), neurocognitive/neurological (93.9%), cardiothoracic (77.9%), Musculoskeletal (78.8%). During long COVID, 62.2% stopped working, and only 32.5% resumed full-time professional activities. Presence of SARS-CoV-2 antibodies before vaccination increased the probability of improvement (aPRR: 1.60, P = 0.028), while ageusia at initial long COVID phase decreased the probability (aPRR: 0.38, P = 0.007).

CONCLUSIONS

Long-COVID symptoms persisted in the majority of participants after 12 months, with significant impacts on daily life and work. SARS-CoV-2 antibodies were associated with better prognosis, while persistent ageusia indicated a lower probability of improvement. These findings highlight the need for ongoing support and care for individuals with long COVID.

Altered mitochondrial respiration in peripheral blood mononuclear cells of post-acute sequelae of SARS-CoV-2 infection

Peripheral blood mononuclear cells (PBMC) mitochondrial respiration was measured ex vivo from participants without a history of COVID (n = 19), with a history of COVID and full recovery (n = 20), and with PASC (n = 20). Mean mitochondrial basal respiration, ATP-linked respiration, maximal respiration, spare respiration capacity, ATP-linked respiration, and non-mitochondrial respiration were highest in COVID + PASC+ (p ≤ 0.04). Every unit increase in non-mitochondrial respiration, ATP-linked respiration, basal respiration, spare respiration capacity, and maximal respiration increased the predicted odds of PASC between 1 % and 6 %. Mitochondrial dysfunction in PBMCs may be contributing to the etiology of PASC.

Long-term risks of respiratory diseases in patients infected with SARS-CoV-2: a longitudinal, population-based cohort study

Background

In the post-pandemic era, growing apprehension exists regarding the potential sequelae of COVID-19. However, the risks of respiratory diseases following SARS-CoV-2 infection have not been comprehensively understood. This study aimed to investigate whether COVID-19 increases the long-term risk of respiratory illness in patients with COVID-19.

Methods

In this longitudinal, population-based cohort study, we built three distinct cohorts age 37-73 years using the UK Biobank database; a COVID-19 group diagnosed in medical records between January 30th, 2020 and October 30th, 2022, and two control groups, a contemporary control group and a historical control group, with cutoff dates of October 30th, 2022 and October 30th, 2019, respectively. The follow-up period of all three groups was 2.7 years (the median (IQR) follow-up time was 0.8 years). Respiratory outcomes diagnosed in medical records included common chronic pulmonary diseases (asthma, bronchiectasis, chronic obstructive pulmonary disease (COPD), interstitial lung disease (ILD), pulmonary vascular disease (PVD), and lung cancer. For the data analysis, we calculated hazard ratios (HRs) along with their 95% CIs using Cox regression models, following the application of inverse probability weights (IPTW).

Findings

A total of 3 cohorts were included in this study; 112,311 individuals in the COVID-19 group with a mean age (±SDs) of 56.2 (8.1) years, 359,671 in the contemporary control group, and 370,979 in the historical control group. Compared with the contemporary control group, those infected with SARS-CoV-2 exhibited elevated risks for developing respiratory diseases. This includes asthma, with a HR of 1.49 and a 95% CI 1.28-1.74; bronchiectasis (1.30; 1.06-1.61); COPD (1.59; 1.41-1.81); ILD (1.81; 1.38-2.21); PVD (1.59; 1.39-1.82); and lung cancer (1.39; 1.13-1.71). With the severity of the acute phase of COVID-19, the risk of pre-described respiratory outcomes increases progressively. Besides, during the 24-months follow-up, we observed an increasing trend in the risks of asthma and bronchiectasis over time. Additionally, the HR of lung cancer for 0-6 month follow-up was 3.07 (CI 1.73-5.44), and the association of lung cancer with COVID-19 disease disappeared at 6-12 month follow-up (1.06; 0.43-2.64) and at 12-24 months (1.02; 0.45-2.34). Compared to those with one SARS-CoV-2 infection, reinfected patients were at a higher risk of asthma (3.0; 1.32-6.84), COPD (3.07; 1.42-6.65), ILD (3.61; 1.11-11.8), and lung cancer (3.20; 1.59-6.45). Similar findings were noted when comparing with a historical cohort serving as a control group, including asthma (1.31; 1.13-1.52); bronchiectasis (1.53; 1.23-1.89); COPD (1.41; 1.24-1.59); ILD (2.53; 2.05-3.13); PVD (2.30; 1.98-2.66); and lung cancer (2.23; 1.78-2.79).

Interpretation

Our research suggests that patients with COVID-19 may have an increased risk of developing respiratory diseases, and the risk increases with the severity of infection and reinfection. Even during the 24-month follow-up, the risk of asthma and bronchiectasis continued to increase. Hence, implementing appropriate follow-up strategies for these individuals is crucial to monitor and manage potential long-term respiratory health issues. Additionally, the increased risk in lung cancer in the COVID-19 individuals was probably due to the diagnostic tests conducted and incidental diagnoses.

Funding

The National Natural Science Foundation of China of China Regional Innovation and Development Joint Foundation; National Natural Science Foundation of China; Program for High-level Foreign Expert Introduction of China; Natural Science Foundation for Distinguished Young Scholars of Guangdong Province; Guangdong Basic and Applied Basic Research Foundation; Climbing Program of Introduced Talents and High-level Hospital Construction Project of Guangdong Provincial People's Hospital; VA Clinical Merit and ASGE clinical research funds.

The S1 subunits of SARS-CoV-2 variants differentially trigger the IL-6 signaling pathway in human brain endothelial cells and downstream impact on microglia activation

Objectives

Cerebrovascular complications are prevalent in COVID-19 infection and post-COVID conditions; therefore, interactions of SARS-CoV-2 with cerebral microvascular cells became an emerging concern.

Methods

We examined the inflammatory responses of human brain microvascular endothelial cells (HBMEC), the main structural element of the blood-brain barrier (BBB), following exposure to the S1 subunit of the spike protein of different SARS-CoV-2 variants. Specifically, we used the S1 subunit derived from the D614 variant of SARS-CoV-2, which started widely circulating in March of 2020, and from the Delta variant, which started widely circulating in early 2021. We then further examined the impact of the HBMEC secretome, produced in response to the S1 exposure, on microglial proinflammatory responses.

Results

Treatment with S1 derived from the D614 variant and from the Delta variant resulted in differential alterations of the IL-6 signaling pathway. Moreover, the HBMEC secretome obtained after exposure to the S1 subunit of the D614 variant activated STAT3 in microglial cells, indicating that proinflammatory signals from endothelial cells can propagate to other cells of the neurovascular unit. Overall, these results indicate the potential for different SARS-CoV-2 variants to induce unique cellular signatures and warrant individualized treatment strategies. The findings from this study also bring further awareness to proinflammatory responses involving brain microvasculature in COVID-19 and demonstrate how the surrounding microglia react to each unique variant derived response.

Cardiovascular dysautonomia in postacute sequelae of SARS-CoV-2 infection

Coronavirus disease 2019 (COVID-19) has led to a worldwide pandemic that continues to transform but will not go away. Cardiovascular dysautonomia in postacute sequelae of severe acute respiratory syndrome coronavirus 2 infection has led to persistent symptoms in a large number of patients. Here, we define the condition and its associated symptoms as well as potential mechanisms responsible. We provide a careful and complete overview of the topic addressing novel studies and a generalized approach to the management of individuals with this complex and potentially debilitating problem. We also discuss future research directions and the important knowledge gaps to be addressed in ongoing and planned studies.

Persistent Risk of Developing Autoimmune Diseases Associated With COVID-19: An Observational Study Using an Electronic Medical Record Database in Japan

OBJECTIVE

This study aimed to investigate the risk of developing autoimmune diseases associated with coronavirus disease 2019 (COVID-19) in Japan, including long-term risks and risks specific to different variants of concern.

METHODS

This observational study used an electronic medical record database in Japan. The COVID-19 group is composed of patients diagnosed with COVID-19, whereas the non-COVID-19 group had data sampled from the database. The outcomes of interest encompassed several autoimmune diseases, including rheumatoid arthritis, systemic sclerosis, and immunoglobulin G4-related disease, as well as a composite of these diseases (any autoimmune disease). We examined the relative risk of autoimmune diseases using standardized mortality ratio weighting and the Cox proportional hazards model. Subgroup analyses based on epidemic variants were performed. In addition, short- and long-term risks were investigated using piecewise constant hazard models.

RESULTS

A total of 90,855 COVID-19 and 459,827 non-COVID-19 patients were included between January 16, 2020, and December 31, 2022. The relative risk of any autoimmune disease was 2.32 (95% confidence interval, 2.08-2.60). All the investigated outcomes showed a significant risk associated with COVID-19. Several autoimmune diseases exhibit a risk associated with COVID-19 in the short to long term, and the long-term risk is substantial for systemic sclerosis and immunoglobulin G4-related disease. The variant-specific risk varied across outcomes.

CONCLUSIONS

COVID-19 is associated with an increased risk of developing autoimmune diseases in the Japanese population, and this effect persists for a long time. This study provides insights into the association between viral infections and autoimmunity.

Pathophysiological, immunological, and inflammatory features of long COVID

The COVID-19 pandemic continues to cause severe global disruption, resulting in significant excess mortality, overwhelming healthcare systems, and imposing substantial social and economic burdens on nations. While most of the attention and therapeutic efforts have concentrated on the acute phase of the disease, a notable proportion of survivors experience persistent symptoms post-infection clearance. This diverse set of symptoms, loosely categorized as long COVID, presents a potential additional public health crisis. It is estimated that 1 in 5 COVID-19 survivors exhibit clinical manifestations consistent with long COVID. Despite this prevalence, the mechanisms and pathophysiology of long COVID remain poorly understood. Alarmingly, evidence suggests that a significant proportion of cases within this clinical condition develop debilitating or disabling symptoms. Hence, urgent priority should be given to further studies on this condition to equip global public health systems for its management. This review provides an overview of available information on this emerging clinical condition, focusing on the affected individuals' epidemiology, pathophysiological mechanisms, and immunological and inflammatory profiles.

The immunobiology of SARS-CoV-2 infection and vaccine responses: potential influences of cross-reactive memory responses and aging on efficacy and off-target effects

Immune responses to both SARS-CoV-2 infection and its associated vaccines have been highly variable within the general population. The increasing evidence of long-lasting symptoms after resolution of infection, called post-acute sequelae of COVID-19 (PASC) or "Long COVID," suggests that immune-mediated mechanisms are at play. Closely related endemic common human coronaviruses (hCoV) can induce pre-existing and potentially cross-reactive immunity, which can then affect primary SARS-CoV-2 infection, as well as vaccination responses. The influence of pre-existing immunity from these hCoVs, as well as responses generated from original CoV2 strains or vaccines on the development of new high-affinity responses to CoV2 antigenic viral variants, needs to be better understood given the need for continuous vaccine adaptation and application in the population. Due in part to thymic involution, normal aging is associated with reduced naïve T cell compartments and impaired primary antigen responsiveness, resulting in a reliance on the pre-existing cross-reactive memory cell pool which may be of lower affinity, restricted in diversity, or of shorter duration. These effects can also be mediated by the presence of down-regulatory anti-idiotype responses which also increase in aging. Given the tremendous heterogeneity of clinical data, utilization of preclinical models offers the greatest ability to assess immune responses under a controlled setting. These models should now involve prior antigen/viral exposure combined with incorporation of modifying factors such as age on immune responses and effects. This will also allow for mechanistic dissection and understanding of the different immune pathways involved in both SARS-CoV-2 pathogen and potential vaccine responses over time and how pre-existing memory responses, including potential anti-idiotype responses, can affect efficacy as well as potential off-target effects in different tissues as well as modeling PASC.

Intra-Host Evolution Analyses in an Immunosuppressed Patient Supports SARS-CoV-2 Viral Reservoir Hypothesis

Throughout the SARS-CoV-2 pandemic, several variants of concern (VOCs) have been identified, many of which share recurrent mutations in the spike glycoprotein's receptor-binding domain (RBD). This region coincides with known epitopes and can therefore have an impact on immune escape. Protracted infections in immunosuppressed patients have been hypothesized to lead to an enrichment of such mutations and therefore drive evolution towards VOCs. Here, we present the case of an immunosuppressed patient that developed distinct populations with immune escape mutations throughout the course of their infection. Notably, by investigating the co-occurrence of substitutions on individual sequencing reads in the RBD, we found quasispecies harboring mutations that confer resistance to known monoclonal antibodies (mAbs) such as S:E484K and S:E484A. These mutations were acquired without the patient being treated with mAbs nor convalescent sera and without them developing a detectable immune response to the virus. We also provide additional evidence for a viral reservoir based on intra-host phylogenetics, which led to a viral substrain that evolved elsewhere in the patient's body, colonizing their upper respiratory tract (URT). The presence of SARS-CoV-2 viral reservoirs can shed light on protracted infections interspersed with periods where the virus is undetectable, and potential explanations for long-COVID cases.

The Binding of the SARS-CoV-2 Spike Protein to Platelet Factor 4: A Proposed Mechanism for the Generation of Pathogenic Antibodies

Pathogenic platelet factor 4 (PF4) antibodies contributed to the abnormal coagulation profiles in COVID-19 and vaccinated patients. However, the mechanism of what triggers the body to produce these antibodies has not yet been clarified. Similar patterns and many comparable features between the COVID-19 virus and heparin-induced thrombocytopenia (HIT) have been reported. Previously, we identified a new mechanism of autoimmunity in HIT in which PF4-antibodies self-clustered PF4 and exposed binding epitopes for other pathogenic PF4/eparin antibodies. Here, we first proved that the SARS-CoV-2 spike protein (SP) also binds to PF4. The binding was evidenced by the increase in mass and optical intensity as observed through quartz crystal microbalance and immunosorbent assay, while the switching of the surface zeta potential caused by protein interactions and binding affinity of PF4-SP were evaluated by dynamic light scattering and isothermal spectral shift analysis. Based on our results, we proposed a mechanism for the generation of PF4 antibodies in COVID-19 patients. We further validated the changes in zeta potential and interaction affinity between PF4 and SP and found that their binding mechanism differs from ACE2-SP binding. Importantly, the PF4/SP complexes facilitate the binding of anti-PF4/Heparin antibodies. Our findings offer a fresh perspective on PF4 engagement with the SARS-CoV-2 SP, illuminating the role of PF4/SP complexes in severe thrombotic events.

The Role of Furin in the Pathogenesis of COVID-19-Associated Neurological Disorders

Neurological disorders have been reported in a large number of coronavirus disease 2019 (COVID-19) patients, suggesting that this disease may have long-term adverse neurological consequences. COVID-19 occurs from infection by a positive-sense single-stranded RNA virus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The membrane fusion protein of SARS-CoV-2, the spike protein, binds to its human host receptor, angiotensin-converting enzyme 2 (ACE2), to initiate membrane fusion between the virus and host cell. The spike protein of SARS-CoV-2 contains the furin protease recognition site and its cleavage enhances the infectivity of this virus. The binding of SARS-CoV-2 to the ACE2 receptor has been shown to downregulate ACE2, thereby increasing the levels of pathogenic angiotensin II (Ang II). The furin protease cleaves between the S1 subunit of the spike protein with the binding domain toward ACE2 and the S2 subunit with the transmembrane domain that anchors to the viral membrane, and this activity releases the S1 subunit into the blood circulation. The released S1 subunit of the spike protein also binds to and downregulates ACE2, in turn increasing the level of Ang II. Considering that a viral particle contains many spike protein molecules, furin-dependent cleavage would release many free S1 protein molecules, each of which can downregulate ACE2, while infection with a viral particle only affects one ACE2 molecule. Therefore, the furin-dependent release of S1 protein would dramatically amplify the ability to downregulate ACE2 and produce Ang II. We hypothesize that this amplification mechanism that the virus possesses, but not the infection per se, is the major driving force behind COVID-19-associated neurological disorders.

Safety and Efficacy of Pulmonary Rehabilitation for Long COVID Patients Experiencing Long-Lasting Symptoms

Due to the high prevalence and persistence of long COVID, it is important to evaluate the safety and efficacy of pulmonary rehabilitation (PR) for patients who experience long-lasting symptoms more than six months after initial COVID-19 onset. Enrolled patients were admitted for a four-week in-patient-PR due to long COVID symptoms (n = 47). The safety of PR was confirmed by the absence of adverse events. Symptom-related outcomes were evaluated pre- and post-PR with significant score changes for: 6 min walking distance (61 [28 to 103] m), quality of life (mental Short Form-12: 10 [6 to 13], and physical: 9 [6 to 12]), Montreal Cognitive Assessment (1 [0 to 3]), fatigue (MFI-20: -19 [-28 to -8]), dyspnea (DYSPNEA-12: -7 [-9 to -2] and mMRC; -1 [-1 to 0]), Nijmegen questionnaire (-8 [-11 to -5]), anxiety and depression (HADS:-4 [-5 to -2] and -2 [-4 to -1], respectively) and posttraumatic stress disorder checklist scale (-8 [-12 to -4]). At the individual level, the percentage of symptomatic patients for each outcome decreased, with a high response rate, and the number of persistent symptoms per patient was reduced from six at PR initiation to three at the end of the program. Our results show that in-PR is safe and efficient at decreasing long-lasting symptoms experienced by long COVID patients at more than six months after initial disease onset.

Unraveling Links between Chronic Inflammation and Long COVID: Workshop Report

As COVID-19 continues, an increasing number of patients develop long COVID symptoms varying in severity that last for weeks, months, or longer. Symptoms commonly include lingering loss of smell and taste, hearing loss, extreme fatigue, and "brain fog." Still, persistent cardiovascular and respiratory problems, muscle weakness, and neurologic issues have also been documented. A major problem is the lack of clear guidelines for diagnosing long COVID. Although some studies suggest that long COVID is due to prolonged inflammation after SARS-CoV-2 infection, the underlying mechanisms remain unclear. The broad range of COVID-19's bodily effects and responses after initial viral infection are also poorly understood. This workshop brought together multidisciplinary experts to showcase and discuss the latest research on long COVID and chronic inflammation that might be associated with the persistent sequelae following COVID-19 infection.

COVID-19 Recovery: Consistent Absence of Cerebrospinal Fluid Biomarker Abnormalities in Patients With Neurocognitive Post-COVID Complications

BACKGROUND

To investigate evidence of residual viral infection, intrathecal immune activation, central nervous system (CNS) injury, and humoral responses in cerebrospinal fluid (CSF) and plasma in patients recovering from coronavirus disease 2019 (COVID-19), with or without neurocognitive post-COVID condition (PCC).

METHODS

Thirty-one participants (25 with neurocognitive PCC) underwent clinical examination, lumbar puncture, and venipuncture ≥3 months after COVID-19 symptom onset. Healthy volunteers were included. CSF and plasma severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid and spike antigen (N-Ag, S-Ag), and CSF biomarkers of immune activation and neuronal injury were analyzed.

RESULTS

SARS-CoV-2 N-Ag or S-Ag were undetectable in all samples and no participant had pleocytosis. We detected no significant differences in CSF and plasma cytokine concentrations, albumin ratio, IgG index, neopterin, β2M, or in CSF biomarkers of neuronal injury and astrocytic damage. Furthermore, principal component analysis (PCA1) analysis did not indicate any significant differences between the study groups in the marker sets cytokines, neuronal markers, or anti-cytokine autoantibodies.

CONCLUSIONS

We found no evidence of ongoing viral replication, immune activation, or CNS injury in plasma or CSF in patients with neurocognitive PCC compared with COVID-19 controls or healthy volunteers, suggesting that neurocognitive PCC is a consequence of events suffered during acute COVID-19 rather than persistent viral CNS infection or residual CNS inflammation.

Post-discharge outcomes of hospitalized children diagnosed with acute SARS-CoV-2 or MIS-C

Introduction

Hospitalized children diagnosed with SARS-CoV-2-related conditions are at risk for new or persistent symptoms and functional impairments. Our objective was to analyze post-hospital symptoms, healthcare utilization, and outcomes of children previously hospitalized and diagnosed with acute SARS-CoV-2 infection or Multisystem Inflammatory Syndrome in Children (MIS-C).

Methods

Prospective, multicenter electronic survey of parents of children <18 years of age surviving hospitalization from 12 U.S. centers between January 2020 and July 2021. The primary outcome was a parent report of child recovery status at the time of the survey (recovered vs. not recovered). Secondary outcomes included new or persistent symptoms, readmissions, and health-related quality of life. Multivariable backward stepwise logistic regression was performed for the association of patient, disease, laboratory, and treatment variables with recovered status.

Results

The children [n = 79; 30 (38.0%) female] with acute SARS-CoV-2 (75.7%) or MIS-C (24.3%) had a median age of 6.5 years (interquartile range 2.0-13.0) and 51 (64.6%) had a preexisting condition. Fifty children (63.3%) required critical care. One-third [23/79 (29.1%)] were not recovered at follow-up [43 (31, 54) months post-discharge]. Admission C-reactive protein levels were higher in children not recovered vs. recovered [5.7 (1.3, 25.1) vs. 1.3 (0.4, 6.3) mg/dl, p = 0.02]. At follow-up, 67% overall had new or persistent symptoms. The most common symptoms were fatigue (37%), weakness (25%), and headache (24%), all with frequencies higher in children not recovered. Forty percent had at least one return emergency visit and 24% had a hospital readmission. Recovered status was associated with better total HRQOL [87 (77, 95) vs. 77 (51, 83), p = 0.01]. In multivariable analysis, lower admission C-reactive protein [odds ratio 0.90 (95% confidence interval 0.82, 0.99)] and higher admission lymphocyte count [1.001 (1.0002, 1.002)] were associated with recovered status.

Conclusions

Children considered recovered by their parents following hospitalization with SARS-CoV-2-related conditions had less symptom frequency and better HRQOL than those reported as not recovered. Increased inflammation and lower lymphocyte count on hospital admission may help to identify children needing longitudinal, multidisciplinary care.

Clinical Trial Registration

ClinicalTrials.gov (NCT04379089).