Interleukin-6 as potential mediator of long-term neuropsychiatric symptoms of COVID-19

Clinical features and predictive nomogram for fatigue sequelae in non-severe patients infected with SARS-CoV-2 Omicron variant in Shanghai, China

Background

Patients with coronavirus disease 2019(COVID-2019) infections may still experience long-term effects, with fatigue being one of the most frequent ones. Clinical research on the long COVID in the Chinese population after infection is comparatively lacking.

Objective

To collect and analyze the long-term effects of non-severe COVID-19 infection patients and to develop a model for the prediction of fatigue symptoms.

Methods

223 non-severe COVID-19 patients admitted to one designated hospital were enrolled after finish all the self-designed clinical information registration form and nine-month follow-up. We explored the frequency and symptom types of long COVID. Correlation analysis was done on the neuropsychological scale results. After cluster analysis, lasoo regression and logistic regressions, a nomogram prediction model was produced as a result of investigating the risk factors for fatigue.

Results

A total of 108 (48.4%) of the 223 non-severe COVID-19 patients reported sequelae for more than 4 weeks, and of these, 35 (15.7%) had fatigue sequelae that were scale-confirmed. Other sequelae of more than 10% were brain fog (n = 37,16.6%), cough (n = 26,11.7%) and insomnia (n = 23,10.3%). A correlation between depression and fatigue was discovered following the completion of neuropsychological scale. The duration of hospitalization, the non-use of antiviral medications in treatment, IL-6 and CD16+CD56+ cell levels in blood are the main independent risk factors and predictors of fatigue sequelae in long COVID. Additionally, the neurology diseases and vaccination status may also influence the fatigue sequelae.

Conclusion

Nearly half of the patients infected with COVID-19 Omicron variant complained of sequelae, and fatigue was the most common symptom, which was correlated with depression. Significant predictors of fatigue sequelae included length of hospitalization, non-use of antiviral drug, and immune-related serum markers of IL-6 and CD16+CD56+ NK cell levels. The presence of neurology diseases and a lack of vaccination could also predict the occurrence of fatigue sequelae.

Anxiety and depression in people with post-COVID condition: a Belgian population-based cohort study three months after SARS-CoV-2 infection

PURPOSE

Since the onset of the COVID-19 pandemic, most research has focused on the management of the acute symptoms of the disease. Yet some people tend to experience symptoms beyond the acute phase, defined as Post-COVID-19 Condition (PCC). This study aims to assess the impact of COVID-19 and PCC on anxiety and depression.

METHODS

This is a prospective longitudinal cohort study among the Belgian adult population with recent SARS-CoV-2 infection for which contact tracing was initiated. A total of 3127 people were followed-up just after their infection and three months later (from April 2021 to January 2022). Anxiety and depression were assessed at the two stages using the GAD-7 (Generalized Anxiety Disorder) and the PHQ-9 (Patient Health Questionnaire).

RESULTS

Three months after infection, participants with PCC (50%) had an increased probability of having both anxiety and depressive symptoms (p < 0.001). The proportion with anxiety and depressive symptoms at three months were significantly higher in people with PCC (11% and 19%) compared to people without persistent COVID symptoms (3.8% and 4.2%) and to a matched sub-sample not infected with SARS-CoV-2 (6.5% and 4.3%). Having at least one acute COVID-19 symptom (p < 0.001), experiencing financial loss following the infection (p < 0.001), and different PCC symptoms were associated with anxiety and depressive symptoms worsening over time.

CONCLUSIONS

This study showed that three months after a SARS-CoV-2 infection, one in two people suffer from PCC with significant consequences for their mental health. Follow-up on mental health must therefore have an important place in people suffering from PCC.

Taiwan Chingguan Yihau may improve post-COVID-19 respiratory complications through PI3K/AKT, HIF-1, and TNF signaling pathways revealed by network pharmacology analysis

The emergence of new SARS-CoV-2 variants with a higher contagious capability and faster transmissible speed has imposed an incessant menace on global health and the economy. The SARS-CoV-2 infection might reoccur and last much longer than expected. Thence, there is a high possibility that COVID-19 can cause long-term health problems. This condition needs to be investigated thoroughly, especially the post-COVID-19 complications. Respiratory tract disorders are common and typical complications after recovery. Until now, there has been a lack of data on specialized therapeutic medicine for post-COVID-19 complications. The clinical efficacy of NRICM101 has been demonstrated in hospitalized COVID-19 patients. This herbal medicine may also be a promising therapy for post-COVID-19 complications, thanks to its phytochemical constituents. The potential pharmacological mechanisms of NRICM101 in treating post-COVID-19 respiratory complications were investigated using network pharmacology combined with molecular docking, and the results revealed that NRICM101 may exert a beneficial effect through the three primary pathways: PI3K/AKT, HIF-1, and TNF signaling pathways. Flavonoids (especially quercetin) have a predominant role and synergize with other active compounds to produce therapeutic effectiveness. Most of the main active compounds exist in three chief herbal ingredients, including Liquorice root (Glycyrrhiza glabra), Scutellaria root (Scutellaria baicalensis), and Mulberry leaf (Morus alba). To our knowledge, this is the first study of the NRICM101 effect on post-COVID-19 respiratory complications. Our findings may provide a better understanding of the potential mechanisms of NRICM101 in treating SARS-CoV-2 infection and regulating the immunoinflammatory response to improve post-COVID-19 respiratory complications.

Trazodone counteracts the response of microglial cells to inflammatory stimuli

Microglia are resident brain cells that regulate neuronal development and innate immunity. Microglia activation participates in the cellular response to neuroinflammation, thus representing a possible target for pharmacological strategies aimed to counteract the onset and progression of brain disorders, including depression. Antidepressant drugs have been reported to reduce neuroinflammation by acting also on glial cells. Herein, the potential anti-inflammatory and neuroprotective effects of trazodone (TRZ) on the microglial human microglial clone 3 (HMC3) cell line were investigated. HMC3 cells were activated by a double inflammatory stimulus (lipopolysaccharide [LPS] and tumour necrosis factor-alpha [TNF-α], 24 h each), and the induction of inflammation was demonstrated by (i) the increased expression levels of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) and ionized calcium-binding adapter molecule 1 (IBA-1), and (ii) the increased release of interleukin 6 (IL-6) and transforming growth factor-beta (TGF-β). TRZ effects were evaluated by treating HMC3 cells for 24 h before (pre-treatment) and after (post-treatment) the double inflammatory stimulus. Notably, TRZ treatments significantly decreased the expression of NF-kB and IBA-1 and the release of the cytokines IL-6 and TGF-β. Moreover, TRZ prevented and reduced the release of quinolinic acid (QUIN), a known neurotoxic kynurenine metabolite. Finally, cellular supernatants collected from microglial cells pre-treated LPS-TNF-α with TRZ were able to improve neuronal-like cell viability, demonstrating a potential neuroprotective effect. Overall, this study suggests the anti-inflammatory effects of TRZ on human microglia and strives for its neuroprotective properties.

The Role of Inflammation in Depression and Beyond: A Primer for Clinicians

PURPOSE OF REVIEW

We evaluate available evidence for the role of inflammation in depression. We reappraise literature involving systemic inflammation, neuroinflammation and neurotransmission and their association with depression. We review the connection between depression, autoimmunity and infectious diseases. We revise anti-inflammatory treatments used in depression.

RECENT FINDINGS

Peripheral inflammatory markers are present in a subset of patients with depression and can alter common neurotransmitters in this population but there is no clear causality between depression and systemic inflammation. Infectious conditions and autoimmune illnesses do not have a clear correlation with depression. Certain medications have positive evidence as adjunctive treatments in depression but studies are heterogenic, hence they are sparsely used in clinical settings. The current evidence does not fully support inflammation, infections or autoimmunity as possible etiologies of depression. The available studies have numerous confounders that obscure the findings. Anti-inflammatory agents may have potential for treatment of depression, but further research is needed to clarify their usefulness in routine clinical practice.

Targeting Cytokines: Evaluating the Potential of Mesenchymal Stem Cell Derived Extracellular Vesicles in the Management of COVID-19

The Coronavirus Disease 2019 (COVID-19), caused by virus SARS-CoV-2, is characterized by massive inflammation and immune system imbalance. Despite the implementation of vaccination protocols, the accessibility of treatment remains uneven. Furthermore, the persistent threat of new variants underscores the urgent need for expanded research into therapeutic options for SARS-CoV-2. Mesenchymal stem cells (MSCs) are known for their immunomodulatory potential through the release of molecules into the extracellular space, either as soluble elements or carried by extracellular vesicles (EVs). The aim of this study was to evaluate the anti-inflammatory potential of EVs obtained from human adipose tissue (ASC-EVs) against SARS-CoV-2 infection. ASC-EVs were purified by size-exclusion chromatography, and co-culture assays confirmed that ASC-EVs were internalized by human lung cells and could colocalize with SARS-CoV-2 into early and late endosomes. To determine the functionality of ASC-EVs, lung cells were infected with SARS-CoV-2 in the presence of increasing concentrations of ASC-EVs, and the release of cytokines, chemokines and viruses were measured. While SARS-CoV-2 replication was significantly reduced only at the highest concentrations tested, multiplex analysis highlighted that lower concentrations of ASC-EV sufficed to prevent the production of immune modulators. Importantly, ASC-EVs did not contain detectable inflammatory cytokines, nor did they trigger inflammatory mediators, nor affect cellular viability. In conclusion, this work suggests that ASC-EVs have the potential to attenuate inflammation by decreasing the production of pro-inflammatory cytokines in lung cells following SARS-CoV-2 infection.

The role of fatigue in patients with complex regional pain syndrome

BACKGROUND AND PURPOSE

Fatigue affects patients across a variety of neurological diseases, including chronic pain syndromes such as complex regional pain syndrome (CRPS). In CRPS, fatigue is often underestimated, as the focus lies in the assessment and managing of pain and sensorimotor deficits. This study aimed to investigate the prevalence, characteristics, and influence of fatigue on CRPS severity and quality of life in these patients. Such insights could enhance the clinical management of this challenging condition.

METHODS

In this prospective study, 181 CRPS patients and 141 age and gender-matched individuals with injury but without chronic pain were interviewed using the Fatigue Scale for Motor and Cognitive Function to assess fatigue. Depressive symptoms and quality of life (QoL) were also evaluated as additional outcome measures. Statistical analysis was performed to examine differences in fatigue prevalence between the groups, as well as associations with CRPS severity, pain levels, and clinical phenotype. In addition, best subsets regression was used to identify the primary factors influencing QoL. Fatigue was tested in a mediation analysis as a mediator between pain and depression.

RESULTS

CRPS patients showed significantly higher fatigue levels compared to controls (CRPS: 75 [IQR: 57-85] vs. controls: 39 [IQR: 25-57]). Based on the FSMC, 44.2% in the control group experienced fatigue, while 85% of patients with CRPS experienced fatigue (p < 0.001), of which 6% were mild, 15% moderate, and 67% severe. In CRPS severe fatigue was associated with higher pain intensities compared to no fatigue (pain at rest: p = 0.003; pain during movement: p = 0.007) or moderate fatigue (pain during movement: p = 0.03). QoL in our cohort was mainly influenced by pain (pain during movement: adj.R2 = 0.38; p < 0.001, pain at rest: Δadj.R2 = 0.02, p = 0.007) and depressive symptoms (Δadj.R2 = 0.12, p < 0.001). Subsequent analyses indicated that pain and depressive symptoms primarily impact QoL in CPRS whereas fatigue may exert an indirect influence by mediating the connection between pain and depression (p < 0.001).

CONCLUSIONS

This pioneering study investigates the prevalence of fatigue in CRPS patients and its relation to disease characteristics. Our results indicate a high prevalence of severe fatigue, strongly correlated with pain intensity, and its importance in the interaction between pain and depression in CRPS. These findings underscore the significant role of fatigue as a disease factor in CRPS. Therefore, the evaluation of CRPS-related disability should include a standardized assessment of fatigue for comprehensive clinical management.

Interleukin-6 signaling pathway in Mendelian randomization: A 10-year bibliometric analysis

Interleukin 6 (IL-6), a pleiotropic cytokine, is crucial in a variety of inflammatory and immunological disorders. In recent years, mendelian randomization, which is a widely used and successful method of analyzing causality, has recently been investigated for the relationship between the IL-6 pathway and related diseases. However, no studies have been conducted to review the research hotspots and trends in the field of IL-6 signaling pathway in Mendelian randomization. In this study, the Web of Science Core Collection (WoSCC) served as our literature source database to gather articles about the IL-6 signaling pathway in Mendelian randomization from 2013 to 2023. VOSviewer (version 1.6.18), Microsoft Excel 2021, and Scimago Graphica were employed for bibliometric and visualization analysis. A total of 164 documents that were written by 981 authors coming from 407 institutions across 41 countries and published in 107 journals were located from January 2013 to August 2023. With 64 and 25, respectively, England and the University of Bristol had the highest number of publications. Frontiers in Immunology is the most prolific journal, and Golam M Khandaker has published the highest number of significant articles. The most co-cited article was an article entitled the interleukin-6 receptor as a target for prevention of coronary-heart-disease: a Mendelian randomization analysis, written by Daniel I Swerdlow. The most popular keywords were "mendelian randomization," "interleukin-6," "il-6," "c-reactive protein," "association," "coronary-heart-disease," "inflammation," "instruments," "risk," "rheumatoid arthritis," "depression." The full extent of the existing literature over the last 10 years is systematically revealed in this study, which can provide readers with a valuable reference for fully comprehending the research hotspots and trends in the field of IL-6 signaling pathway in Mendelian randomization.

[Interaction of somatic findings and psychiatric symptoms in COVID-19. A scoping review]

An infection with SARS-CoV‑2 can affect the central nervous system, leading to neurological as well as psychiatric symptoms. In this respect, mechanisms of inflammation seem to be of much greater importance than the virus itself. This paper deals with the possible contributions of organic changes to psychiatric symptomatology and deals especially with delirium, cognitive symptoms, depression, anxiety, posttraumatic stress disorder and psychosis. Processes of neuroinflammation with infection of capillary endothelial cells and activation of microglia and astrocytes releasing high amounts of cytokines seem to be of key importance in all kinds of disturbances. They can lead to damage in grey and white matter, impairment of cerebral metabolism and loss of connectivity. Such neuroimmunological processes have been described as a organic basis for many psychiatric disorders, as affective disorders, psychoses and dementia. As the activation of the glia cells can persist for a long time after the offending agent has been cleared, this can contribute to long term sequalae of the infection.

Multi-target drugs for the treatment of cognitive impairment and fatigue in post-COVID syndrome: focus on Ginkgo biloba and Rhodiola rosea

Cognitive impairment, depression and (mental) fatigue represent the most frequent neuropsychiatric symptoms of the post-COVID syndrome. Neuroinflammation, oxidative stress and mitochondrial dysfunction have been identified as common pathophysiological mechanisms underlying these symptoms. Attempts to treat post-COVID-associated cognitive impairment and fatigue with different drugs available for other diseases have not yet been successful. One probable explanation could be that these drugs work by one specific mechanism of action only and not in a broad multi-target way. Therefore, they will not address the broad pathophysiological spectrum possibly responsible for cognitive impairment, depression and fatigue in post-COVID syndrome. Notably, nearly all drugs currently under investigation for fatigue in post-COVID syndrome are rather addressing one single target instead of the several pathomechanisms underlying this condition. Contrary to this approach, herbal drugs often consist of many different ingredients with different pharmacological properties and pharmacological targets. Therefore, these drugs might be a promising approach for the treatment of the broad symptomatic presentation and the pathophysiological mechanisms of cognitive impairment and fatigue following a SARS-CoV-2 infection. Of these herbal drugs, extracts of Ginkgo biloba and Rhodiola rosea probably are the best investigated candidates. Their broad pharmacological spectrum in vitro and in vivo includes anti-oxidative, anti-inflammatory, antidepressant as well as properties reducing cognitive impairment and fatigue. In several studies, both drugs showed positive effects on physical and mental fatigue and impaired cognition. Moreover, depressive symptoms were also reduced in some studies. However, even if these results are promising, the data are still preliminary and require additional proof by further studies.

IL-6 and IL-17 as potential links between pre-existing hypertension and long-term COVID sequelae in patients undergoing hemodialysis: a multicenter cross-sectional study

Long COVID, characterized by persistent symptoms following acute infection, poses a significant health challenge, particularly for patients with pre-existing chronic conditions such as hypertension. We hypothesized that an increase in the production of interleukins (IL)-6 and IL-17 could serve as a potential mechanism linking pre-existing uncontrolled blood pressure (BP) to the occurrence of long-term COVID sequelae in patients undergoing hemodialysis (HD). This cross-sectional study examined serum IL-6 and IL-17 levels in 80 patients undergoing HD, considering preinfection BP, the presence of long-term COVID sequelae, and the time interval after acute COVID-19 infection, which was either 5 or 10 months. Controlled BP was defined as a 3-month average pre-dialysis BP < 140/90 mmHg and post-dialysis < 130/80 mmHg. The findings suggest that the prevalence of long-term COVID sequelae was significantly higher in patients with uncontrolled BP than in the BP-controlled group. Both IL-6 and IL-17 concentrations were also significantly higher in patients with uncontrolled BP compared with the BP-controlled group. The patients with long-term COVID sequelae had higher IL-6 and IL-17 values than the fully recovered patients at both time points, but their concentrations decreased significantly over time. Further research and prospective studies are warranted to validate these findings.

Predictors for Long COVID and Differences in Long COVID Symptoms, Findings on Chest Imaging and Pulmonary Function between Hospitalized COVID-19 Patients with versus without Intensive Care Unit Admission

INTRODUCTION

Many COVID-19 survivors suffer from persisting sequelae after acute disease. This is referred to as long COVID. The objectives of this study were to assess factors associated with long COVID and to analyze differences in persistent symptoms, findings on chest imaging, and pulmonary function between intensive care unit (ICU) and non-ICU hospitalized patients.

METHODS

We conducted a retrospective study including patients hospitalized with COVID-19. Patients were stratified into ICU patients and non-ICU patients. We analyzed the outcomes of patients who were in clinical follow-up 6 months after discharge with persistent symptoms, radiological and/or functional abnormalities. Logistic regression was used to examine the association between long COVID and patient characteristics.

RESULTS

A total of 549 patients were included. Eighty-one ICU patients (66%) and 146 (34%) non-ICU patients had persistent symptoms or abnormalities on chest imaging or lung function test minimally 6 months after discharge. Significantly more ICU patients had residual fibrotic abnormalities on chest CT and functional impairment. Female gender, myocardial infarction, OSAS, low PCO2 at admission, and longer hospital stay were associated with a higher risk of developing long COVID. Diabetes and treatment with tocilizumab were associated with a lower risk of developing long COVID.

CONCLUSION

Of the patients hospitalized for COVID-19, 34-66% suffered from persistent symptoms, residual abnormalities on chest imaging, or reduced lung function at around 6 months after discharge. While persistent sequelae were more frequent in ICU patients, admission to the ICU was not found to be an independent risk factor for developing long COVID.

Longer-Term Mental Health Consequences of COVID-19 Infection: Moderation by Race and Socioeconomic Status

OBJECTIVE

While evidence suggests that the mental health symptoms of COVID-19 can persist for several months following infection, little is known about the longer-term mental health effects and whether certain sociodemographic groups may be particularly impacted. This cross-sectional study aimed to characterize the longer-term mental health consequences of COVID-19 infection and examine whether such consequences are more pronounced in Black people and people with lower socioeconomic status.

METHODS

277 Black and White adults (age ≥ 30 years) with a history of COVID-19 (tested positive ≥ 6 months prior to participation) or no history of COVID-19 infection completed a 45-minute online questionnaire battery.

RESULTS

People with a history of COVID-19 had greater depressive (d = 0.24), anxiety (d = 0.34), post-traumatic stress disorder (PTSD) (d = 0.32), and insomnia (d = 0.31) symptoms than those without a history of COVID-19. These differences remained for anxiety, PTSD, and insomnia symptoms after adjusting for age, sex, race, education, income, employment status, body mass index, and smoking status. No differences were detected for perceived stress and general psychopathology. People with a history of COVID-19 had more than double the odds of clinically significant symptoms of anxiety (OR = 2.22) and PTSD (OR = 2.40). Education, but not race, income, or employment status, moderated relationships of interest such that COVID-19 status was more strongly and positively associated with all the mental health outcomes for those with fewer years of education.

CONCLUSION

The mental health consequences of COVID-19 may be significant, widespread, and persistent for at least 6 months post-infection and may increase as years of education decreases.

Cytokines (IL1β, IL6, TNFα) and serum cortisol levels may not constitute reliable biomarkers to identify individuals with post-acute sequelae of COVID-19

Background

Post-acute sequelae of COVID-19 (PASC) comprise a broad spectrum of symptoms such as fatigue, general weakness, compromised attention and sleep or anxiety disorders. PASC represents a medical and socio-economic challenge.

Objectives

Our study evaluated cytokines (IL-1β, IL-6 and TNFα) and cortisol levels in a cohort of typical patients with PASC, suffering concentration problems, fatigue and difficulties finding words.

Design

This was a prospective cohort study. Four groups were analysed and compared: those who had never contracted SARS-CoV-2 (n = 13), infected but had no PASC (n = 34), infected with former PASC that resolved (n = 40) and patients with ongoing PASC after infection (n = 91).

Methods

Cytokine and cortisol serum levels were determined in patients' blood samples.

Results

Cytokine levels of IL-1β, IL-6, TNFα and cortisol levels did not differ between groups analysed.

Conclusion

This may indicate a non-organic/psychosomatic genesis of PASC; further studies are needed to elucidate the underlying causes of PACS, and non-organic causes should not be overlooked.

The global prevalence of depression, anxiety, and sleep disorder among patients coping with Post COVID-19 syndrome (long COVID): a systematic review and meta-analysis

BACKGROUND

Post COVID-19 syndrome, also known as "Long COVID," is a complex and multifaceted condition that affects individuals who have recovered from SARS-CoV-2 infection. This systematic review and meta-analysis aim to comprehensively assess the global prevalence of depression, anxiety, and sleep disorder in individuals coping with Post COVID-19 syndrome.

METHODS

A rigorous search of electronic databases was conducted to identify original studies until 24 January 2023. The inclusion criteria comprised studies employing previously validated assessment tools for depression, anxiety, and sleep disorders, reporting prevalence rates, and encompassing patients of all age groups and geographical regions for subgroup analysis Random effects model was utilized for the meta-analysis. Meta-regression analysis was done.

RESULTS

The pooled prevalence of depression and anxiety among patients coping with Post COVID-19 syndrome was estimated to be 23% (95% CI: 20%-26%; I2 = 99.9%) based on data from 143 studies with 7,782,124 participants and 132 studies with 9,320,687 participants, respectively. The pooled prevalence of sleep disorder among these patients, derived from 27 studies with 15,362 participants, was estimated to be 45% (95% CI: 37%-53%; I2 = 98.7%). Subgroup analyses based on geographical regions and assessment scales revealed significant variations in prevalence rates. Meta-regression analysis showed significant correlations between the prevalence and total sample size of studies, the age of participants, and the percentage of male participants. Publication bias was assessed using Doi plot visualization and the Peters test, revealing a potential source of publication bias for depression (p = 0.0085) and sleep disorder (p = 0.02). However, no evidence of publication bias was found for anxiety (p = 0.11).

CONCLUSION

This systematic review and meta-analysis demonstrate a considerable burden of mental health issues, including depression, anxiety, and sleep disorders, among individuals recovering from COVID-19. The findings emphasize the need for comprehensive mental health support and tailored interventions for patients experiencing persistent symptoms after COVID-19 recovery.

Alteration of white matter microstructure in patients with sleep disorders after COVID-19 infection

BACKGROUND

The pathophysiology of coronasomnia remains unclear. This study aimed to investigate changes in white matter (WM) microstructure and inflammatory factors in patients with sleep disorders (SD) characterized by poor sleep quantity, quality, or timing following coronavirus disease 2019 (COVID-19) infection in the acute phase (within one month) and whether these changes could be recovered at 3-month follow-up.

METHODS

29 acute COVID-19 patients with SD (COVID_SD) and 27 acute COVID-19 patients without SD (COVID_NonSD) underwent diffusion tensor imaging (DTI), tested peripheral blood inflammatory cytokines level, and measured Pittsburgh Sleep Quality Index (PSQI), and matched 30 uninfected healthy controls. Analyzed WM abnormalities between groups in acute phase and explored its changes in COVID_SD at 3-month follow-up by using tract-based spatial statistics (TBSS). Correlations between DTI and clinical data were examined using Spearman partial correlation analysis.

RESULTS

Both COVID_SD and COVID_NonSD exhibited widespread WM microstructure abnormalities. The COVID_SD group showed specific WM microstructure changes in right inferior fronto-occipital fasciculus (IFOF) (lower fractional anisotropy [FA]/axial diffusivity [AD] and higher radial diffusivity [RD]) and left corticospinal tract (CST) (higher FA and lower RD) and higher interleukin-1β (IL-1β) compared with COVID_NonSD group. These WM abnormalities and IL-1β levels were correlated PSQI score. After 3 months, the IFOF integrity and IL-1β levels tended to return to normal accompanied by symptom improvement in the COVID_SD relative to baseline.

CONCLUSION

Abnormalities in right IFOF and left CST and elevated IL-1β levels were important neurophenotypes correlated with COVID_SD, which might provide new insights into the pathogenesis of neuroinflammation in SD patients induced by COVID-19.

Cortical thickness alterations and systemic inflammation define long-COVID patients with cognitive impairment

As the heterogeneity of symptoms is increasingly recognized among long-COVID patients, it appears highly relevant to study potential pathophysiological differences along the different subtypes. Preliminary evidence suggests distinct alterations in brain structure and systemic inflammatory patterns in specific groups of long-COVID patients. To this end, we analyzed differences in cortical thickness and peripheral immune signature between clinical subgroups based on 3 T-MRI scans and signature inflammatory markers in n = 120 participants comprising healthy never-infected controls (n = 30), healthy COVID-19 survivors (n = 29), and subgroups of long-COVID patients with (n = 26) and without (n = 35) cognitive impairment according to screening with Montreal Cognitive Assessment. Whole-brain comparison of cortical thickness between the 4 groups was conducted by surface-based morphometry. We identified distinct cortical areas showing a progressive increase in cortical thickness across different groups, starting from healthy individuals who had never been infected with COVID-19, followed by healthy COVID-19 survivors, long-COVID patients without cognitive deficits (MoCA ≥ 26), and finally, long-COVID patients exhibiting significant cognitive deficits (MoCA < 26). These findings highlight the continuum of cortical thickness alterations associated with COVID-19, with more pronounced changes observed in individuals experiencing cognitive impairment (p < 0.05, FWE-corrected). Affected cortical regions covered prefrontal and temporal gyri, insula, posterior cingulate, parahippocampal gyrus, and parietal areas. Additionally, we discovered a distinct immunophenotype, with elevated levels of IL-10, IFNγ, and sTREM2 in long-COVID patients, especially in the group suffering from cognitive impairment. We demonstrate lingering cortical and immunological alterations in healthy and impaired subgroups of COVID-19 survivors. This implies a complex underlying pathomechanism in long-COVID and emphasizes the necessity to investigate the whole spectrum of post-COVID biology to determine targeted treatment strategies targeting specific sub-groups.

The demographic, laboratory and genetic factors associated with long Covid-19 syndrome: a case-control study

Long Covid-19 syndrome (LCS) manifests with a wide range of clinical symptoms, yet the factors associated with LCS remain poorly understood. The current study aimed to investigate the relationships that demographic characteristics, clinical history, laboratory indicators, and the frequency of HLA-I alleles have with the likelihood of developing LCS. We extracted the demographic characteristics and clinical histories from the medical records of 88 LCS cases (LCS+ group) and 96 individuals without LCS (LCS- group). Furthermore, we evaluated the clinical symptoms, serum levels of interleukin (IL)-6 and tumor necrosis factor-α, laboratory parameters, and the frequencies of HLA-I alleles. Following this we used multiple logistic regression to investigate the association these variables had with LCS. Subjects in the LCS+ group were more likely to have experienced severe Covid-19 symptoms and had higher body mass index (BMI), white blood cell, lymphocyte counts, C-reactive protein (CRP), and IL-6 levels than those in the LCS- group (for all: P < 0.05). Moreover, the frequencies of the HLA-A*11, -B*14, -B*38, -B*50, and -C*07 alleles were higher in the LCS+ group (for all: P < 0.05). After adjusting for the most important variables, the likelihood of suffering from LCS was significantly associated with BMI, CRP, IL-6, the HLA-A*11, and -C*07 alleles, as well as a positive history of severe Covid-19 (for all: P < 0.05). Our study showed that a history of severe Covid-19 during the acute phase of the disease, the HLA-A*11, and -C*07 alleles, higher BMI, as well as elevated serum CRP and IL-6 levels, were all associated with an increased likelihood of LCS.

COVID-19 convalescent plasma therapy decreases inflammatory cytokines: a randomized controlled trial

IMPORTANCE

This study examined the role that cytokines may have played in the beneficial outcomes found when outpatient individuals infected with SARS-CoV-2 were transfused with COVID-19 convalescent plasma (CCP) early in their infection. We found that the pro-inflammatory cytokine IL-6 decreased significantly faster in patients treated early with CCP. Participants with COVID-19 treated with CCP later in the infection did not have the same effect. This decrease in IL-6 levels after early CCP treatment suggests a possible role of inflammation in COVID-19 progression. The evidence of IL-6 involvement brings insight into the possible mechanisms involved in CCP treatment mitigating SARS-CoV-2 severity.

Interleukin 6 Antagonists in Severe COVID-19 Disease: Cardiovascular and Respiratory Outcomes

BACKGROUND

Inhibitors of interleukin 6 [IL-6] have been utilized to treat severe COVID-19 disease. Their immunosuppressive or immunomodulating impact may be beneficial in COVID-19.

OBJECTIVES

To discuss the role of IL-6 inhibitors and assess various trials conducted to evaluate the efficacy of IL-6 inhibitors in COVID-19 disease.

SUMMARY

Two of the most common causes of mortality in COVID-19-infected critically ill individuals are acute respiratory distress syndrome (ARDS) and multiorgan failure. Increased levels of inflammatory cytokines suggest that a cytokine storm, also known as cytokine release syndrome (CRS), is involved in the etiology of COVID-19. Most tissue damage, sepsis, and pulmonary and cardiovascular problems are caused mainly by the host defense system. Therefore, regulating this inflammatory cascade using immunomodulators is a prudent strategy. Although corticosteroids, as immunomodulators, are routinely used in COVID-19 management, interleukin (IL) inhibitors, especially IL-6 inhibitors, are also tested in many trials. Many studies have demonstrated that IL-6 inhibitors improve disease outcomes and decrease mortality, whereas others have shown that they are ineffective. In this paper, we briefly examined the role of IL-6 in COVID-19 pathogenesis and trials that support or refute the use of IL-6 inhibitors in treating COVID-19 disease.

RESULTS

Though mixed results are coming from trials regarding the adjuvant use of IL-6 inhibitors and standard anti-viral therapy with dexamethasone, a consensus favors using IL-6 inhibitors in severely ill COVID-19 patients regardless of the outcome.

High level of psychological stress in COVID-19 recovered individuals: role of copeptin as a potential biomarker

Background

Study aimed to assess stress in COVID-19 recovered individuals using a validated questionnaire PSS-10 score and stress biomarkers - salivary cortisol and serum copeptin.

Methods

A total of 83 subjects of which 54 subjects (66.3%) who were hospitalized were recruited 8-20 weeks following recovery from COVID-19. Stress was assessed by PSS-10 stress-scale after a mean duration of 14.5 weeks after recovery. Sixty-eight subjects (81.9%) had new or persistent symptoms after recovery. Subjects were divided into two groups on the basis of PSS score; mild stress (PSS:0-13) and moderate to severe stress (PSS:>14) and levels of biomarkers (serum copeptin, DHEAS and salivary cortisol) were compared in the two groups.

Results

Forty-four subjects (53%) had moderate to severe stress and 39 subjects (47%) had mild stress. Subjects with post COVID symptoms had significantly higher stress levels as compared to subjects who were asymptomatic [15 vs. 9; p = 0.003]. Serum copeptin levels were significantly higher among subjects with moderate to severe stress as compared to those with mild stress [0.41 vs. 0.67 ng/mL; p = 0.031]. Subjects with moderate to severe stress had higher median salivary cortisol compared to subjects with mild stress [1.03 vs. 1.44 nmol/L; p = 0.448].

Conclusion

Our study demonstrated moderate to severe stress in over half and some level of stress in nearly all COVID recovered individuals even after 3 months. Serum copeptin was found to be a useful biomarker to objectively measure stress in these subjects.

Long COVID or Post-COVID-19 Condition: Past, Present and Future Research Directions

The presence of symptoms after an acute SARS-CoV-2 infection (long-COVID) has become a worldwide healthcare emergency but remains underestimated and undertreated due to a lack of recognition of the condition and knowledge of the underlying mechanisms. In fact, the prevalence of post-COVID symptoms ranges from 50% during the first months after the infection up to 20% two-years after. This perspective review aimed to map the existing literature on post-COVID symptoms and to identify gaps in the literature to guide the global effort toward an improved understanding of long-COVID and suggest future research directions. There is a plethora of symptomatology that can be due to COVID-19; however, today, there is no clear classification and definition of this condition, termed long-COVID or post-COVID-19 condition. The heterogeneity in the symptomatology has led to the presence of groups/clusters of patients, which could exhibit different risk factors and different mechanisms. Viral persistence, long-lasting inflammation, immune dysregulation, autoimmune reactions, reactivation of latent infections, endothelial dysfunction and alteration in gut microbiota have been proposed as potential mechanisms explaining the complexity of long-COVID. In such an equation, viral biology (e.g., re-infections, SARS-CoV-2 variants), host biology (e.g., genetics, epigenetics) and external factors (e.g., vaccination) should be also considered. These various factors will be discussed in the current perspective review and future directions suggested.

Increased risk of chronic fatigue syndrome following infection: a 17-year population-based cohort study

BACKGROUND

Previous serological studies have indicated an association between viruses and atypical pathogens and Chronic Fatigue Syndrome (CFS). This study aims to investigate the correlation between infections from common pathogens, including typical bacteria, and the subsequent risk of developing CFS. The analysis is based on data from Taiwan's National Health Insurance Research Database.

METHODS

From 2000 to 2017, we included a total of 395,811 cases aged 20 years or older newly diagnosed with infection. The cases were matched 1:1 with controls using a propensity score and were followed up until diagnoses of CFS were made.

RESULTS

The Cox proportional hazards regression analysis was used to estimate the relationship between infection and the subsequent risk of CFS. The incidence density rates among non-infection and infection population were 3.67 and 5.40 per 1000 person-years, respectively (adjusted hazard ratio [HR] = 1.5, with a 95% confidence interval [CI] 1.47-1.54). Patients infected with Varicella-zoster virus, Mycobacterium tuberculosis, Escherichia coli, Candida, Salmonella, Staphylococcus aureus and influenza virus had a significantly higher risk of CFS than those without these pathogens (p < 0.05). Patients taking doxycycline, azithromycin, moxifloxacin, levofloxacin, or ciprofloxacin had a significantly lower risk of CFS than patients in the corresponding control group (p < 0.05).

CONCLUSION

Our population-based retrospective cohort study found that infection with common pathogens, including bacteria, viruses, is associated with an increased risk of developing CFS.

Post-COVID-19 depression and serum interleukin 6 levels: A systematic review and meta-analysis of COVID-19 convalescents with and without depression

OBJECTIVES

Depression is among the psychiatric sequelae of COVID-19, affecting more than 20% of the convalescents. Its underlying pathophysiology remains unclear. Interleukin 6 (IL-6), a pro-inflammatory cytokine, plays a critical role in the COVID-19-associated cytokine storm, has been implicated in depressive disorders, and may thus be involved in post-COVID-19 depression.

METHODS

PubMed, Scopus, Embase, and Web of Science were systematically searched for relevant studies assessing peripheral IL-6 levels in convalescents who developed depression after COVID-19 vs. convalescents who did not.

RESULTS

Five studies were included in our systematic review, and four entered the meta-analysis. The meta-analysis revealed that post-COVID people with de novo depression did not have statistically significant differences in IL-6 levels compared to those without depression (standardised mean difference (SMD) = 0.09, 95% confidence interval (CI) = -0.35, 0.54, p-value = 0.68).

CONCLUSIONS

Although convalescents with depression did not have significantly higher IL-6 levels than convalescents without depression, the results should be interpreted considering the limited sample size and the low power of the included studies.

Allergic diseases as risk factors for Long-COVID symptoms: Systematic review of prospective cohort studies

OBJECTIVE

The role of allergy as a risk factor for Long-COVID (LC) is unclear and has not been thoroughly examined yet. We aimed to systematically review and appraise the epidemiological evidence on allergic diseases as risk factors for LC.

DESIGN

This is an initial systematic review. Two reviewers independently performed the study selection and data extraction using Covidence. Risk of bias (RoB) and certainty of evidence (GRADE) were assessed. Random effects meta-analyses were used to pool unadjusted ORs within homogeneous data subsets.

DATA SOURCES

We retrieved articles published between January 1st, 2020 and January 19th, 2023 from MEDLINE via PubMed, Scopus, the WHO-COVID-19 database and the LOVE platform (Epistemonikos Foundation). In addition, citations and reference lists were searched.

ELIGIBILITY CRITERIA

We included prospective cohort studies recruiting individuals of all ages with confirmed SARS-CoV-2 infection that were followed up for at least 12 months for LC symptoms where information on pre-existing allergic diseases was available. We excluded all study designs that were not prospective cohort studies and all publication types that were not original articles.

RESULTS

We identified 13 studies (9967 participants, range 39-1950 per study), all assessed as high RoB, due to population selection and methods used to ascertain the exposures and the outcome. Four studies did not provide sufficient data to calculate Odds Ratios. The evidence supported a possible relationship between LC and allergy, but was very uncertain. For example, pre-existing asthma measured in hospital-based populations (6 studies, 4019 participants) may be associated with increased risk of LC (Odds Ratio 1.94, 95% CI 1.08, 3.50) and findings were similar for pre-existing rhinitis (3 studies, 1141 participants; Odds Ratio 1.96, 95% CI 1.61, 2.39), both very low certainty evidence.

CONCLUSIONS

Pre-existing asthma or rhinitis may increase the risk of LC.

Persistent endothelial dysfunction in post-COVID-19 syndrome and its associations with symptom severity and chronic inflammation

BACKGROUND

Post-COVID-19 syndrome (PCS) is a lingering disease with ongoing symptoms such as fatigue and cognitive impairment resulting in a high impact on the daily life of patients. Understanding the pathophysiology of PCS is a public health priority, as it still poses a diagnostic and treatment challenge for physicians.

METHODS

In this prospective observational cohort study, we analyzed the retinal microcirculation using Retinal Vessel Analysis (RVA) in a cohort of patients with PCS and compared it to an age- and gender-matched healthy cohort (n = 41, matched out of n = 204).

MEASUREMENTS AND MAIN RESULTS

PCS patients exhibit persistent endothelial dysfunction (ED), as indicated by significantly lower venular flicker-induced dilation (vFID; 3.42% ± 1.77% vs. 4.64% ± 2.59%; p = 0.02), narrower central retinal artery equivalent (CRAE; 178.1 [167.5-190.2] vs. 189.1 [179.4-197.2], p = 0.01) and lower arteriolar-venular ratio (AVR; (0.84 [0.8-0.9] vs. 0.88 [0.8-0.9], p = 0.007). When combining AVR and vFID, predicted scores reached good ability to discriminate groups (area under the curve: 0.75). Higher PCS severity scores correlated with lower AVR (R = - 0.37 p = 0.017). The association of microvascular changes with PCS severity were amplified in PCS patients exhibiting higher levels of inflammatory parameters.

CONCLUSION

Our results demonstrate that prolonged endothelial dysfunction is a hallmark of PCS, and impairments of the microcirculation seem to explain ongoing symptoms in patients. As potential therapies for PCS emerge, RVA parameters may become relevant as clinical biomarkers for diagnosis and therapy management.

TRIAL REGISTRATION

This study was previously registered at ClinicalTrials ("All Eyes on PCS-Analysis of the Retinal Microvasculature in Patients with Post-COVID-19 Syndrome". NCT05635552. https://clinicaltrials.gov/ct2/show/NCT05635552 ). Persistent endothelial dysfunction in post-COVID-19 syndrome. Acute SARS-CoV-2 infection indirectly or directly causes endotheliitis in patients. N = 41 PCS patients were recruited and retinal vessel analysis was performed to assess microvascular endothelial function. Images of SVA and DVA are illustrative for RVA data analysis. For each PCS patient and healthy cohort, venular vessel diameter of the three measurement cycles was calculated and plotted on a diameter-time curve. Patients exhibited reduced flicker-induced dilation in veins (vFID) measured by dynamic vessel analysis (DVA) and lower central retinal arteriolar equivalent (CRAE) and arteriolar-venular ratio (AVR) and a tendency towards higher central retinal venular equivalent (CRVE) when compared to SARS-CoV-2 infection naïve participants. Created with BioRender.com.

Understanding COVID-19 progression with longitudinal peripheral blood mononuclear cell proteomics: Changes in the cellular proteome over time

The clinical presentation of COVID-19 is highly variable, and understanding the underlying biological processes is crucial. This study utilized a proteomic analysis to investigate dysregulated processes in the peripheral blood mononuclear cells of patients with COVID-19 compared to healthy volunteers. Samples were collected at different stages of the disease, including hospital admission, after 7 days of hospitalization, and 30 days after discharge. Metabolic pathway alterations and increased abundance of neutrophil-related proteins were observed in patients. Patients progressing to critical illness had significantly low-abundance proteins in the pentose phosphate and glycolysis pathways compared with those presenting clinical recovery. Important biological processes, such as fatty acid concentration and glucose metabolism disorder, remained altered even after 30 days of hospital discharge. Temporal proteomic changes revealed distinct pathways in critically ill and non-critically ill patients. Our study emphasizes the significance of longitudinal cellular proteomic studies in identifying disease progression-related pathways and persistent protein changes post-hospitalization.

Intranasal ketamine as a treatment for psychiatric complications of long COVID: A case report

Background

Neuropsychiatric symptoms associated with long COVID are a growing concern. A proposed pathophysiology is increased inflammatory mediators. There is evidence that typical serotonergic antidepressants have limited efficacy in the presence of inflammation. Although ketamine has shown promise in MDD, there is limited evidence supporting the use of ketamine to treat depressive symptoms associated with long COVID.

Case Report

This case took place on an inpatient psychiatry unit in a Canadian hospital. The patient was admitted with a 10-month history of worsening depression and suicidality following infection with COVID-19. Depressive symptoms and suicidal ideation were assessed throughout treatment using the Montgomery-Asberg Depression Rating Scale (MADRS). Written informed consent was obtained prior to data collection. This patient received 4 doses of intranasal ketamine which resulted in rapid improvement of depressive symptoms and complete resolution of suicidality with no major adverse events.

Discussion

There is evidence to support long COVID symptoms result from dysregulated inflammatory processes. The presence of inflammation in patients with MDD has correlated to poor outcomes with first-line antidepressants. It has been demonstrated that IV ketamine is associated with decreased inflammatory mediators and proportional decrease in depressive symptoms.

Conclusions

Intranasal ketamine in this case was effective at treating depressive symptoms and suicidal ideation associated with long COVID. This is consistent with available data that demonstrates ketamine's efficacy in reducing inflammatory mediators associated with neuropsychiatric symptoms. Therefore, ketamine may be a potential therapeutic option to treat long COVID and persistent depressive symptoms.

The Effect of Potassium Canrenoate (Mineralocorticoid Receptor Antagonist) on the Markers of Inflammation in the Treatment of COVID-19 Pneumonia and Fibrosis-A Secondary Analysis of Randomized Placebo-Controlled Clinical Trial

In March 2020, the World Health Organization (WHO) announced a global pandemic of coronavirus disease 2019 (COVID-19) that presented mainly as an acute infection of the lower respiratory tract (pneumonia), with multiple long-term consequences, including lung fibrosis. The aim of this study was to evaluate the influence of potassium canrenoate on inflammatory markers in the treatment of COVID-19 pneumonia. A randomized clinical trial (RCT) of intravenous potassium canrenoate vs. placebo was performed between December 2020 and November 2021. This study is a secondary analysis of that RCT. In the final analysis, a total of 49 hospitalized patients were included (24 allocated to the potassium canrenoate group and 25 to the placebo group). Patients were assessed by serum testing and blood cell cytometry on day 1 and day 7 of the intervention. Age, sex, and body mass index were not significantly different between the placebo group and intervention group. Although there was a significantly higher rate of ischemic heart disease in the placebo group, rates of other preexisting comorbidities were not significantly different. There were no significant differences in the inflammatory parameters between the potassium canrenoate and placebo groups on day 1 and day 7. However, the intragroup comparisons using Wilcoxon's test showed significant differences between day 1 and day 7. The CD3% for potassium canrenoate increased significantly between day 1 and day 7 (12.85 ± 9.46; 11.55 vs. 20.50 ± 14.40; 17.80; p = 0.022), while the change in the placebo group was not significant (15.66 ± 11.39; 12.65 vs. 21.16 ± 15.37; 16.40; p = 0.181). The IL-1ß total count [%] increased over time for both potassium canrenoate (0.68 ± 0.58; 0.45 vs. 1.27 ± 0.83; 1.20; p = 0.004) and placebo (0.61 ± 0.59; 0.40 vs. 1.16 ± 0.91; 1.00; p = 0.016). The TNF-α total count (%) decreased significantly between day 1 and day 7 for potassium canrenoate (0.54 ± 0.45; 0.40 vs. 0.25 ± 0.23; 0.10; p = 0.031), but not for placebo (0.53 ± 0.47; 0.35 vs. 0.26 ± 0.31; 0.20; p = 0.056). Interleukin-6 (pg/mL) showed a significant decrease between day 1 and day 7 for potassium canrenoate (64.97 ± 72.52; 41.00 vs. 24.20 ± 69.38; 5.30; p = 0.006), but not the placebo group. This RCT has shown that the administration of potassium canrenoate to patients with COVID-19-induced pneumonia may be associated with significant changes in certain inflammatory markers (interleukin-6, CD3%, TNF-α), potentially related to pulmonary fibrosis. Although some positive trends were observed in the potassium canrenoate group, none of these observations reached statistical significance. Any possible benefits from the use of potassium canrenoate as an anti-inflammatory or antifibrotic drug in COVID-19 patients require further investigation.

Mild to moderate post-COVID-19 alters markers of lymphocyte activation, exhaustion, and immunometabolic responses that can be partially associated by physical activity level- an observational sub-analysis fit- COVID study

Aim

This study aimed to evaluate if physical activity is associated with systemic and cellular immunometabolic responses, in young adults after mild-to-moderate COVID-19 infection.

Methods

Mild- to- moderate post-COVID-19 patients (70.50 ± 43.10 days of diagnosis; age: 29.4 (21.9- 34.9) years; BMI: 25.5 ± 4.3 kg m2 n = 20) and healthy age-matched controls (age: 29.3 (21.2 - 32.6) years; BMI: 25.4 ± 4.7 kg m2; n = 20) were evaluated. Physical activity levels (PAL), body composition, dietary habits, muscular and pulmonary function, mental health, sleep quality, metabolic parameters, immune phenotypic characterization, stimulated whole blood and PBMC culture (cytokine production), mRNA, and mitochondrial respiration in PBMCs were evaluated.

Results

The post-COVID-19 group exhibited lower levels of moderate to vigorous physical activity (MVPA) (p = 0.038); therefore, all study comparisons were performed with adjustment for MVPA. Post-COVID-19 impacted the pulmonary function (FEV1, FEV1%pred, FVC, and FVC %pred) compared with the control (p adjusted by MVPA (p adj) <0.05). Post-COVID-19 exhibited lower levels of serum IL-6 (p adj <0.01), whereas it showed higher serum IL-10, triglyceride, leptin, IgG, ACE activity, TNFRSF1A, and PGE2 (p adj <0.05) levels compared with controls. Post-COVID-19 presented a lower percentage of Treg cells (p adj = 0.03) and altered markers of lymphocyte activation and exhaustion (lower CD28 expression in CD8+ T cells (p adj = 0.014), whereas CD4+T cells showed higher PD1 expression (p adj = 0.037)) compared with the control group. Finally, post- COVID-19 presented an increased LPS-stimulated whole- blood IL-10 concentration (p adj <0.01). When exploring mitochondrial respiration and gene expression in PBMCs, we observed a higher LEAK state value (p adj <0.01), lower OXPHOS activity (complex I) (p adj = 0.04), and expression of the Rev-Erb-α clock mRNA after LPS stimulation in the post-COVID-19 patients than in the control (p adj <0.01). Mainly, PAL was associated with changes in IL-10, triglyceride, and leptin levels in the plasma of post-COVID-19 patients. PAL was also associated with modulation of the peripheral frequency of Treg cells and the expression of PD-1 in CD8+ T cells, although it abrogated the statistical effect in the analysis of TNF-α and IL-6 production by LPS- and PMA-stimulated PBMC of post-COVID-19 patients.

Conclusion

Young adults after mild-to-moderate SARS-CoV-2 infection appeared to have lower physical activity levels, which can be associated with clinical and immunometabolic responses in a complex manner.

Elevated complement C3 and increased CD8 and type 1 helper lymphocyte T populations in patients with post-COVID-19 condition

BACKGROUND

Biological markers associated to post-COVID-19 condition (PCC) have not been clearly identified.

METHODS

Eighty-two patients attending our post-COVID-19 outpatient clinic were recruited and classified as fully recovered (40.2%) or presenting with PCC (59.8%). Clinical and radiological data, laboratory markers, cytokines, and lymphocyte populations were analyzed.

RESULTS

Median number of days after hospitalization was 78.5 [p25-p75: 60-93] days. PCC was significantly more frequent in women, in patients with a previously critical COVID-19, and in those with two or more comorbidities. No differences were found in lymphocyte counts, ferritin, C-reactive protein, D-dimer or sCD25, IL-1β, IL-1Ra, IL-6, CXCL8, IL-17A, IL-18, IL-22, IFN-γ, TNF-α, and IL-10 cytokines levels. PCC patients showed significantly higher levels of complement factor C3 than fully recovered patients: median C3 128 mg/dL [p25-p75:107-135] vs 111 mg/dL [p25-p75: 100-125] (p =.005), respectively. In the flow cytometry assessment of peripheral blood lymphocyte subpopulations, PCC patients showed significantly increased CD8 populations compared to fully recovered patients: median CD8: 529 [p25-p75: 384-683] vs 370/mm3 [p25-p75:280-523], p =.007. When type 1, 2, 17/22, and 17.1 helper and follicular T lymphocyte subpopulations were analyzed, the frequency of Th1 was significantly higher in PCC patients compared to fully recovered patients (30% vs 38.5%, p =.028).

CONCLUSION

Patients with a post-COVID-19 condition showed significantly increased immunological parameters of inflammation (complement factor C3 and CD8 and Th1 T lymphocyte populations) compared to fully recovered patients. These parameters could be used as biological markers of this condition.

Psychiatric manifestations of post-COVID-19 syndrome: the potential benefit of Silexan

Objective: Psychiatric symptoms are common and bothersome in individuals with post-COVID-19 syndrome. Because they are often mixed and subthreshold, established treatment regimens cannot be applied. There is an urgent need to identify therapeutics for affected patients. Silexan, a proprietary essential oil from Lavandula angustifolia, has demonstrated efficacy against anxiety, comorbid symptoms, and subthreshold and mixed syndromes. The aim of the current narrative review is to examine the therapeutic potential of Silexan for psychiatric manifestations in patients with post-COVID-19 syndrome.Methods: We reviewed clinical evidence regarding the efficacy of Silexan and first clinical experience in patients with psychiatric symptoms attributable to the post-COVID-19 syndrome. Furthermore, we discussed potential modes of action based on nonclinical data.Results: Silexan has demonstrated therapeutic efficacy for the treatment of generalised anxiety disorder; subsyndromal anxiety disorders; comorbid depressive, somatic, and sleep disturbance symptoms; and mixed anxiety and depression. Emerging clinical experience also suggests the effectiveness and tolerability of Silexan for patients with post-COVID-19 syndrome. This can be explained by the fact that the therapeutic profile of Silexan overlaps with the spectrum of psychiatric symptoms in such patients.Conclusion: Preliminary findings indicate a promising potential of Silexan for the treatment of psychiatric manifestations in patients with post-COVID-19 syndrome.Key pointsAnxiety and mixed neuropsychiatric manifestations are commonly observed in patients with post-COVID-19 syndrome.Silexan has anxiolytic properties and can alleviate comorbid depressive, somatic, and sleep impairment symptoms.Silexan exhibits several biological mechanisms, such as neurotrophic and anti-inflammatory properties, which have the potential to positively impact post-COVID-19 disease.Silexan has a favourable safety profile and high acceptance among patients.Emerging data suggest that Silexan can alleviate neuropsychiatric symptoms in patients with post-COVID-19 syndrome.Silexan should be considered as a therapeutic in patients with psychiatric manifestations of post-COVID-19 syndrome.

Inflammatory and mental health sequelae of COVID-19

The COVID-19 pandemic has caused significant negative consequences to mental health. Increased inflammatory factors and neuropsychiatric symptoms, such as cognitive impairment ("brain fog"), depression, and anxiety are associated with long COVID [post-acute sequelae of SARS-CoV-2 infection (PASC), termed neuro-PASC]. The present study sought to examine the role of inflammatory factors as predictors of neuropsychiatric symptom severity in the context of COVID-19. Adults (n = 52) who tested negative or positive for COVID-19 were asked to complete self-report questionnaires and to provide blood samples for multiplex immunoassays. Participants who tested negative for COVID-19 were assessed at baseline and at a follow-up study visit (∼4 weeks later). Individuals without COVID-19 reported significantly lower PHQ-4 scores at the follow-up visit, as compared to baseline (p = 0.03; 95% CI-1.67 to -0.084). Individuals who tested positive for COVID-19 and experienced neuro-PASC had PHQ-4 scores in the moderate range. The majority of people with neuro-PASC reported experiencing brain fog (70% vs. 30%). Those with more severe COVID-19 had significantly higher PHQ-4 scores, as compared to those with mild disease (p = 0.008; 95% CI 1.32 to 7.97). Changes in neuropsychiatric symptom severity were accompanied by alterations in immune factors, particularly monokine induced by gamma interferon (IFN-γ) (MIG, a. k.a. CXCL9). These findings add to the growing evidence supporting the usefulness of circulating MIG levels as a biomarker reflecting IFN-γ production, which is important because individuals with neuro-PASC have elevated IFN-γ responses to internal SARS-CoV-2 proteins.

Neurological manifestations of post-acute sequelae of COVID-19: which liquid biomarker should we use?

Long COVID syndrome, also known as post-acute sequelae of COVID-19 (PASC), is characterized by persistent symptoms lasting 3-12 weeks post SARS-CoV-2 infection. Patients suffering from PASC can display a myriad of symptoms that greatly diminish quality of life, the most frequent being neuropsychiatric. Thus, there is an eminent need to diagnose and treat PASC related neuropsychiatric manifestation (neuro-PASC). Evidence suggests that liquid biomarkers could potentially be used in the diagnosis and monitoring of patients. Undoubtedly, such biomarkers would greatly benefit clinicians in the management of patients; however, it remains unclear if these can be reliably used in this context. In this mini review, we highlight promising liquid (blood and cerebrospinal fluid) biomarkers, namely, neuronal injury biomarkers NfL, GFAP, and tau proteins as well as neuroinflammatory biomarkers IL-6, IL-10, TNF-α, and CPR associated with neuro-PASC and discuss their limitations in clinical applicability.

Subgroups of Patients with Distinct Health Utility Profiles after AKI

Key Points

Health utility profiles can be identified at 60 days after AKI. Patient subgroups with distinct health utility profiles have different characteristics at index hospitalization and outcomes at 1 year. These profiles may be useful when considering resources to improve the physical and emotional health of patients after AKI.

Background

A large amount of interindividual variability exists in health-related quality of life outcomes after AKI. This study aimed to determine whether subgroups of early AKI survivors could be identified on the basis of distinct health utility impairment profiles ascertained at 60 days after AKI and whether these subgroups differed in clinical and biomarker characteristics at index hospitalization and outcomes at 1-year follow-up.

Methods

This retrospective analysis used data from the Biologic Markers of Renal Recovery for the Kidney study, an observational subcohort of the Acute Renal Failure Trial Network study. Of 402 patients who survived to 60 days after AKI, 338 completed the Health Utility Index 3 survey, which measures impairments in eight health attributes. Latent class analysis was used to identify subgroups of patients with distinct health utility profiles.

Results

Three subgroups with distinct health utility impairment profiles were identified: Low (28% of participants), Moderate (58%), and High (14%) with a median of one, four, and six impairments across the eight health attributes at 60 days after AKI, respectively. Patient subgroups differed in weight, history of cerebrovascular disease, intensity of dialysis, hospital length of stay, and dialysis dependence. Serum creatinine and blood urea nitrogen at index hospitalization did not differ among the three subgroups. The High impairment subgroup had higher levels of IL-6 and soluble TNF receptor 2 at study day 1. The three subgroups had different 1-year mortality rates: 5% in the Low, 21% in the Moderate, and 52% in the High impairment subgroup.

Conclusion

Patient subgroups with distinct health utility impairment profiles can be identified 60 days after AKI. These subgroups have different characteristics at index hospitalization. A higher level of impairment at 60 days was associated with decreased survival.

Exhaled Breath Condensate and Respiratory Sequelae in Children Post-COVID-19

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes an acute respiratory illness. A substantial proportion of adults experience persistent symptoms. There is a paucity of data on respiratory sequelae in children. Exhaled breath condensate (EBC) is a non-invasive tool used to assess airway inflammation.

OBJECTIVES

This study aimed to evaluate EBC parameters, respiratory, mental and physical ability among children post COVID-19 infection.

METHODS

Observational study of confirmed SARS-CoV-2 infection cases among children, aged 5-18 years, evaluated once, 1-6 months post positive SARS-CoV-2 PCR testing. All subjects performed spirometry, 6-min walk test (6MWT), EBC (pH, interleukin-6), and completed medical history questionnaires, Depression, Anxiety, and Stress Scale (DASS-21), and physical activity scores. Severity of COVID-19 disease was classified according to WHO criteria.

RESULTS

Fifty-eight children were included and classified asymptomatic (n = 14), mild (n = 37), and moderate (n = 7) disease. The asymptomatic group included younger patients compared to the mild and moderate groups (8.9 ± 2.5y vs. 12.3 ± 3.6y and 14.6 ± 2.5y, respectively, p = 0.001), as well as lower DASS-21 total scores (3.4 ± 4 vs. 8.7 ± 9.4 and 8.7 ± 0.6 respectively, p = 0.056), with higher scores in proximity to positive PCR (p = 0.011). No differences were found between the 3 groups regarding EBC, 6MWT, spirometry, body mass index percentile, and activity scores.

CONCLUSIONS

COVID-19 is an asymptomatic-mild disease in most young healthy children, with gradually diminishing emotional symptoms. Children without prolonged respiratory symptoms revealed no significant pulmonary sequelae as evaluated by EBC markers, spirometry, 6MWT, and activity scores. Larger studies are required to assess long-term pediatric consequences of post SARS-CoV-2 infection, to assess the need for pulmonology surveillance.

New onset or relapsing neuromyelitis optica temporally associated with SARS-CoV-2 infection and COVID-19 vaccination: a systematic review

Background

Neuromyelitis optica spectrum disorder (NMOSD) is a rare chronic neuroinflammatory autoimmune condition. Since the onset of the COVID-19 pandemic, there have been reports of NMOSD clinical manifestations following both SARS-CoV-2 infections and COVID-19 vaccinations.

Objective

This study aims to systematically review the published literature of NMOSD clinical manifestations associated with SARS-CoV-2 infections and COVID-19 vaccinations.

Methods

A Boolean search of the medical literature was conducted between December 1, 2019 to September 1, 2022, utilizing Medline, Cochrane Library, Embase, Trip Database, Clinicaltrials.gov, Scopus, and Web of Science databases. Articles were collated and managed on Covidence^® software. The authors independently appraised the articles for meeting study criteria and followed PRISMA guidelines. The literature search included all case reports and case series that met study criteria and involved NMOSD following either the SARS-CoV-2 infection or the COVID-19 vaccination.

Results

A total of 702 articles were imported for screening. After removing 352 duplicates and 313 articles based on exclusion criteria, 34 articles were analyzed. A total of 41 cases were selected, including 15 patients that developed new onset NMOSD following a SARS-CoV-2 infection, 21 patients that developed de novo NMOSD following COVID-19 vaccination, 3 patients with known NMOSD that experienced a relapse following vaccination, and 2 patients with presumed Multiple Sclerosis (MS) that was unmasked as NMOSD post-vaccination. There was a female preponderance of 76% among all NMOSD cases. The median time interval between the initial SARS-CoV-2 infection symptoms and NMOSD symptom onset was 14  days (range 3-120  days) and the median interval between COVID-19 vaccination and onset of NMO symptoms was 10  days (range 1 to 97  days). Transverse myelitis was the most common neurological manifestation in all patient groups (27/41). Management encompassed acute treatments such as high dose intravenous methylprednisolone, plasmapheresis, and intravenous immunoglobulin (IVIG) and maintenance immunotherapies. The majority of patients experienced a favorable outcome with complete or partial recovery, but 3 patients died.

Conclusion

This systematic review suggests that there is an association between NMOSD and SARS-CoV-2 infections and COVID-19 vaccinations. This association requires further study using quantitative epidemiological assessments in a large population to better quantify the risk.

Long-COVID fatigue is not predicted by pre-pandemic plasma IL-6 levels in mild COVID-19

OBJECTIVE AND DESIGN

Fatigue is a prominent symptom in the general population and may follow viral infection, including SARS-CoV2 infection which causes COVID-19. Chronic fatigue lasting more than three months is the major symptom of the post-COVID syndrome (known colloquially as long-COVID). The mechanisms underlying long-COVID fatigue are unknown. We hypothesized that the development of long-COVID chronic fatigue is driven by the pro-inflammatory immune status of an individual prior to COVID-19.

SUBJECTS AND METHODS

We analyzed pre-pandemic plasma levels of IL-6, which plays a key role in persistent fatigue, in N = 1274 community dwelling adults from TwinsUK. Subsequent COVID-19-positive and -negative participants were categorized based on SARS-CoV-2 antigen and antibody testing. Chronic fatigue was assessed using the Chalder Fatigue Scale.

RESULTS

COVID-19-positive participants exhibited mild disease. Chronic fatigue was a prevalent symptom among this population and significantly higher in positive vs. negative participants (17% vs 11%, respectively; p = 0.001). The qualitative nature of chronic fatigue as determined by individual questionnaire responses was similar in positive and negative participants. Pre-pandemic plasma IL-6 levels were positively associated with chronic fatigue in negative, but not positive individuals. Raised BMI was associated with chronic fatigue in positive participants.

CONCLUSIONS

Pre-existing increased IL-6 levels may contribute to chronic fatigue symptoms, but there was no increased risk in individuals with mild COVID-19 compared with uninfected individuals. Elevated BMI also increased the risk of chronic fatigue in mild COVID-19, consistent with previous reports.

Increased interleukin-6 is associated with long COVID-19: a systematic review and meta-analysis

BACKGROUND

Coronavirus disease 2019 (COVID-19) can involve persistence, sequelae, and other clinical complications that last weeks to months to evolve into long COVID-19. Exploratory studies have suggested that interleukin-6 (IL-6) is related to COVID-19; however, the correlation between IL-6 and long COVID-19 is unknown. We designed a systematic review and meta-analysis to assess the relationship between IL-6 levels and long COVID-19.

METHODS

Databases were systematically searched for articles with data on long COVID-19 and IL-6 levels published before September 2022. A total of 22 published studies were eligible for inclusion following the PRISMA guidelines. Analysis of data was undertaken by using Cochran's Q test and the Higgins I-squared (I²) statistic for heterogeneity. Random-effect meta-analyses were conducted to pool the IL-6 levels of long COVID-19 patients and to compare the differences in IL-6 levels among the long COVID-19, healthy, non-postacute sequelae of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (non-PASC), and acute COVID-19 populations. The funnel plot and Egger's test were used to assess potential publication bias. Sensitivity analysis was used to test the stability of the results.

RESULTS

An increase in IL-6 levels was observed after SARS-CoV-2 infection. The pooled estimate of IL-6 revealed a mean value of 20.92 pg/ml (95% CI = 9.30-32.54 pg/ml, I² = 100%, P < 0.01) for long COVID-19 patients. The forest plot showed high levels of IL-6 for long COVID-19 compared with healthy controls (mean difference = 9.75 pg/ml, 95% CI = 5.75-13.75 pg/ml, I² = 100%, P < 0.00001) and PASC category (mean difference = 3.32 pg/ml, 95% CI = 0.22-6.42 pg/ml, I² = 88%, P = 0.04). The symmetry of the funnel plots was not obvious, and Egger's test showed that there was no significant small study effect in all groups.

CONCLUSIONS

This study showed that increased IL-6 correlates with long COVID-19. Such an informative revelation suggests IL-6 as a basic determinant to predict long COVID-19 or at least inform on the "early stage" of long COVID-19.

Cellular and molecular biomarkers of long COVID: a scoping review

BACKGROUND

Long-COVID (LC) encompasses diverse symptoms lasting months after the initial SARS-CoV-2 infection. Symptoms can be debilitating and affect the quality of life of individuals with LC and their families. Although the symptoms of LC are well described, the aetiology of LC remains unclear, and consequently, patients may be underdiagnosed. Identification of LC specific biomarkers is therefore paramount for the diagnosis and clinical management of the syndrome. This scoping review describes the molecular and cellular biomarkers that have been identified to date with potential use for diagnosis or prediction of LC.

METHODS

This review was conducted using the Joanna Briggs Institute (JBI) Methodology for Scoping Reviews. A search was executed in the MEDLINE and EMBASE databases, as well as in the grey literature for original studies, published until October 5th, 2022, reporting biomarkers identified in participants with LC symptoms (from all ages, ethnicities, and sex), with a previous infection of SARS-CoV-2. Non-English studies, cross-sectional studies, studies without a control group, and pre-prints were excluded. Two reviewers independently evaluated the studies, extracted population data and associated biomarkers.

FINDINGS

23 cohort studies were identified, involving 2163 LC patients [median age 51.8 years, predominantly female sex (61.10%), white (75%), and non-vaccinated (99%)]. A total of 239 candidate biomarkers were identified, consisting mainly of immune cells, immunoglobulins, cytokines, and other plasma proteins. 19 of the 239 candidate biomarkers identified were evaluated by the authors, by means of receiver operating characteristic (ROC) curves.

INTERPRETATION

Diverse cellular and molecular biomarkers for LC have been proposed. Validation of candidate biomarkers in independent samples should be prioritized. Modest reported performance (particularly in larger studies) suggests LC may encompass many distinct aetiologies, which should be explored e.g., by stratifying by symptom clusters and/or sex.

FUNDING

Dr. Tebbutt has received funding from the Canadian Institutes of Health Research (177747) to conduct this work. The funding source was not involved in this scoping review, or in the decision to submit this manuscript for publication.

A review of cytokine-based pathophysiology of Long COVID symptoms

The Long COVID/Post Acute Sequelae of COVID-19 (PASC) group includes patients with initial mild-to-moderate symptoms during the acute phase of the illness, in whom recovery is prolonged, or new symptoms are developed over months. Here, we propose a description of the pathophysiology of the Long COVID presentation based on inflammatory cytokine cascades and the p38 MAP kinase signaling pathways that regulate cytokine production. In this model, the SARS-CoV-2 viral infection is hypothesized to trigger a dysregulated peripheral immune system activation with subsequent cytokine release. Chronic low-grade inflammation leads to dysregulated brain microglia with an exaggerated release of central cytokines, producing neuroinflammation. Immunothrombosis linked to chronic inflammation with microclot formation leads to decreased tissue perfusion and ischemia. Intermittent fatigue, Post Exertional Malaise (PEM), CNS symptoms with "brain fog," arthralgias, paresthesias, dysautonomia, and GI and ophthalmic problems can consequently arise as result of the elevated peripheral and central cytokines. There are abundant similarities between symptoms in Long COVID and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). DNA polymorphisms and viral-induced epigenetic changes to cytokine gene expression may lead to chronic inflammation in Long COVID patients, predisposing some to develop autoimmunity, which may be the gateway to ME/CFS.

Post-COVID-19 Syndrome Comprehensive Assessment: From Clinical Diagnosis to Imaging and Biochemical-Guided Diagnosis and Management

The COVID-19 outbreak was first reported in 2019, causing massive morbidity and mortality. The majority of the COVID-19 patients survived and developed Post-COVID-19 Syndrome (PC19S) of varying severity. Currently, the diagnosis of PC19S is achieved through history and symptomatology that cannot be explained by an alternative diagnosis. However, the heavy reliance on subjective reporting is prone to reporting errors. Besides, there is no unified diagnostic assessment tool to classify the clinical severity of patients. This leads to significant difficulties when managing patients in terms of public resource utilization, clinical progression monitorization and rehabilitation plan formulation. This narrative review aims to review current evidence of diagnosis based on triple assessment: clinical symptomatology, biochemical analysis and imaging evidence. Further assessment tools can be developed based on triple assessment to monitor patient's clinical progression, prognosis and intervals of monitoring. It also highlights the high-risk features of patients for closer and earlier monitoring. Rehabilitation programs and related clinical trials are evaluated; however, most of them focus on cardiorespiratory fitness and psychiatric presentations such as anxiety and depression. Further research is required to establish an objective and comprehensive assessment tool to facilitate clinical management and rehabilitation plans.

Neuropsychiatric aspects of long COVID: A comprehensive review

Although some patients have persistent symptoms or develop new symptoms following coronavirus disease 2019 (COVID-19) infection, neuropsychiatric aspects of long COVID are not well known. This review summarizes and provides an update on the neuropsychiatric dimensions of long COVID. Its neuropsychiatric manifestations commonly include fatigue, cognitive impairment, sleep disorders, depression, anxiety, and post-traumatic stress disorder. There are no specific tests for long COVID, but some characteristic findings such as hypometabolism on positron emission tomography have been reported. The possible mechanisms of long COVID include inflammation, ischemic effects, direct viral invasion, and social and environmental changes. Some patient characteristics and the severity and complications of acute COVID-19 infection may be associated with an increased risk of neuropsychiatric symptoms. Long COVID may resolve spontaneously or persist, depending on the type of neuropsychiatric symptoms. Although established treatments are lacking, various psychological and pharmacological treatments have been attempted. Vaccination against COVID-19 infection plays a key role in the prevention of long coronavirus disease. With differences among the SARS-CoV-2 variants, including the omicron variant, the aspects of long COVID are likely to change in the future. Further studies clarifying the aspects of long COVID to develop effective treatments are warranted.

Can Baseline IL-6 Levels Predict Long COVID in Subjects Hospitalized for SARS-CoV-2 Disease?

The immune response to infection plays a crucial role in the pathogenesis of COVID-19, but several patients develop a wide range of persistent symptoms, which is becoming a major global health and economic burden. However, reliable indicators are not yet available to predict the persistence of symptoms typical of the so-called long COVID. Our study aims to explore an eventual role of IL-6 levels as a marker of long COVID. Altogether, 184 patients admitted to the COVID Medicine Unit of the University Hospital in Palermo, Italy, from the 1st of September 2020, were analyzed. Patients were divided into two groups according to the IL-6 serum levels (normal or elevated), considering the serum IL-6 levels measured during the first four days of hospitalization. In our study, higher serum IL-6 levels were associated with a doubled higher risk of long COVID (OR = 2.05; 95% CI: 1.04-4.50) and, in particular, they were associated with a higher incidence of mobility decline (OR = 2.55; 95% CI: 1.08-9.40) and PTSD (OR = 2.38; 95% CI: 1.06-8.61). The analysis of our case series confirmed the prominent role of IL-6 levels in response to SARS-CoV-2 infection, as predictors not only of COVID-19 disease severity and unfavorable outcomes, but also long COVID development trends.

Psychological treatment of traumatic memories in COVID-19 survivors

The COVID-19 pandemic, which has affected a significant number of individuals worldwide, is generating serious mental health issues. Recovered COVID-19 patients have experienced traumatic events related to their symptoms, isolation, possible hospitalization, bereavement, fear of infecting loved ones and the physical consequences of COVID-19. One effective psychological treatment for these patients is Eye Movement Desensitization and Reprocessing (EMDR). The aim of this paper is to describe the therapeutic intervention and effects of EMDR in a pool of COVID-19 survivors referred to an integrated psychological/psychiatric outpatient service. Twelve patients, comprising of nine males and three females, underwent EMDR psychotherapy from October 2020 to February 2022. Each patient received 8-16 weekly treatment sessions. The standard EMDR protocol of eight stages was administered to enable desensitization and reprocessing of four main targets: first positive swab, hospitalization, isolation and fear for relatives' health. Efficacy of EMDR was demonstrated by the significant improvement at clinical scale for subjective distress caused by traumatic events. For the therapists, carrying out these treatments was an intense and challenging experience. In fact, the perceived distance between therapist and patient was less defined than in other hospital settings because the pandemic affects everyone equally. However, with the widespread availability of vaccines and although the pandemic is still ongoing with the emergence of new variants, a window of improvement in the mental health landscape is starting to open up.

A scoping review of regulatory T cell dynamics in convalescent COVID-19 patients - indications for their potential involvement in the development of Long COVID?

Background

Recovery from coronavirus disease 2019 (COVID-19) can be impaired by the persistence of symptoms or new-onset health complications, commonly referred to as Long COVID. In a subset of patients, Long COVID is associated with immune system perturbations of unknown etiology, which could be related to compromised immunoregulatory mechanisms.

Objective

The objective of this scoping review was to summarize the existing literature regarding the frequency and functionality of Tregs in convalescent COVID-19 patients and to explore indications for their potential involvement in the development of Long COVID.

Design

A systematic search of studies investigating Tregs during COVID-19 convalescence was conducted on MEDLINE (via Pubmed) and Web of Science.

Results

The literature search yielded 17 relevant studies, of which three included a distinct cohort of patients with Long COVID. The reviewed studies suggest that the Treg population of COVID-19 patients can reconstitute quantitatively and functionally during recovery. However, the comparison between recovered and seronegative controls revealed that an infection-induced dysregulation of the Treg compartment can be sustained for at least several months. The small number of studies investigating Tregs in Long COVID allowed no firm conclusions to be drawn about their involvement in the syndrome's etiology. Yet, even almost one year post-infection Long COVID patients exhibit significantly altered proportions of Tregs within the CD4+ T cell population.

Conclusions

Persistent alterations in cell frequency in Long COVID patients indicate that Treg dysregulation might be linked to immune system-associated sequelae. Future studies should aim to address the association of Treg adaptations with different symptom clusters and blood parameters beyond the sole quantification of cell frequencies while adhering to consensualized phenotyping strategies.

Case report: Treatment of long COVID with a SARS-CoV-2 antiviral and IL-6 blockade in a patient with rheumatoid arthritis and SARS-CoV-2 antigen persistence

Introduction

Long COVID, or post-acute sequelae of SARS-CoV-2 infection (PASC) in ∼30% of all infected individuals. Here, we present a case of PASC in a patient with rheumatoid arthritis characterized by viral persistence in the nasopharynx for 6 months after acute infection. We demonstrate transient disappearance of antigen persistence and decreased antiviral and autoimmune T cell responses after nirmatrelvir/ritonavir and tocilizumab treatment.

Case presentation

A 37-year-old female with a 7-year history of rheumatoid arthritis enrolled in a COVID-19 research study was found to continuously test SARS-CoV-2 antigen positive in the nasopharynx for 6 months after acute infection. She simultaneously presented with new-onset PASC symptoms including chronic occipital headache and periods of intense fatigue 8 weeks after acute infection. The patient was prescribed nirmatrelvir/ritonavir to treat SARS-CoV-2 persistence at 3.5 months post-acute infection and observed a reduction in PASC symptoms 3 weeks after completing antiviral treatment. After resurgence of PASC symptoms, she stopped treatment with tocilizumab for rheumatoid arthritis to attempt complete SARS-CoV-2 viral clearance. The severity of the patient's PASC symptoms subsequently increased, and she developed new-onset brain fog in addition to previous symptoms, which resolved after resumption of tocilizumab treatment. Assessment of adaptive immune responses demonstrated that nirmatrelvir/ritonavir and tocilizumab treatment decreased antiviral and autoreactive T cell activation. After resuming tocilizumab treatment, the patient's PASC symptoms were significantly reduced, but nasopharyngeal antigen positivity remained.

Conclusion

These data suggest that nirmatrelvir/ritonavir should be considered in the treatment of PASC in patients who have SARS-CoV-2 antigen persistence, though care must be taken to monitor the patient for symptom resurgence or viral reactivation. In addition, the IL-6 inhibitor tocilizumab may ameliorate PASC symptoms in patients with persistent headache, fatigue, and brain fog.

The CSHQ-DE Questionnaire Uncovers Relevant Sleep Disorders in Children and Adolescents with Long COVID

Acute SARS-CoV-2 infections in children and adolescents are usually mild. However, they can suffer from ongoing symptoms, generally referred to as long COVID. Sleep disorders are one of the most frequent complaints in long COVID although precise data are missing. We assessed the sleep behavior of children and adolescents who presented at our outpatient clinic between January 2021 and May 2022 with the Children's Sleep Habits Questionnaire (CSHQ-DE). We compared the sleep behavior at three different time points: pre-COVID-19; post-COVID-19 at the initial presentation; and post-COVID-19 at re-presentation. Data from 45 patients were analyzed. Of those, 64% were female and the median age was 10 years (range: 0-18 years). Asymptomatic or mild COVID-19 disease was experienced in 89% of patients; 11% experienced moderate disease. The initial presentation occurred at a median of 20.4 weeks (6 weeks-14 months) after the infection. The CSHQ-DE score increased significantly from pre-COVID-19 (45.82 ± 8.7 points) to post-COVID-19 (49.40 ± 8.3 points; p ≤ 0.01). The score then normalized at re-presentation (46.98 ± 7.8; p = 0.1). The greatest changes were seen in the CSHQ-DE subscale score "daytime sleepiness". Our data showed that children and adolescents with long COVID often suffer from sleep disturbances. For most children and adolescents, these sleep disorders decreased over time without any further medical intervention aside from a basic sleep consultation.

The Mito-Hormetic Mechanisms of Ozone in the Clearance of SARS-CoV2 and in the COVID-19 Therapy

An increasing body of evidence in the literature is reporting the feasibility of using medical ozone as a possible alternative and adjuvant treatment for COVID-19 patients, significantly reducing hospitalization time, pro-inflammatory indicators, and coagulation markers and improving blood oxygenation parameters. In addition to the well-described ability of medical ozone in counteracting oxidative stress through the upregulation of the main anti-oxidant and scavenging enzymes, oxygen–ozone (O₂–O₃) therapy has also proved effective in reducing chronic inflammation and the occurrence of immune thrombosis, two key players involved in COVID-19 exacerbation and severity. As chronic inflammation and oxidative stress are also reported to be among the main drivers of the long sequelae of SARS-CoV2 infection, a rising number of studies is investigating the potential of O₂–O₃ therapy to reduce and/or prevent the wide range of post-COVID (or PASC)-related disorders. This narrative review aims to describe the molecular mechanisms through which medical ozone acts, to summarize the clinical evidence on the use of O₂–O₃ therapy as an alternative and adjuvant COVID-19 treatment, and to discuss the emerging potential of this approach in the context of PASC symptoms, thus offering new insights into effective and safe nonantiviral therapies for the fighting of this devastating pandemic.