Post-COVID syndrome is associated with capillary alterations, macrophage infiltration and distinct transcriptomic signatures in skeletal muscles

Abstract:

The SARS-CoV-2 pandemic not only resulted in millions of acute infections worldwide, but also caused innumerable cases of post-infectious syndromes, colloquially referred to as “long COVID”. Due to the heterogeneous nature of symptoms and scarcity of available tissue samples, little is known about the underlying mechanisms. We present an in-depth analysis of skeletal muscle biopsies obtained from eleven patients suffering from enduring fatigue and post-exertional malaise after an infection with SARS-CoV-2.

Compared to two independent historical control cohorts, patients with post-COVID exertion intolerance had fewer capillaries, thicker capillary basement membranes and increased numbers of CD169+ macrophages. SARS-CoV-2 RNA could not be detected in the muscle tissues, but transcriptomic analysis revealed distinct gene signatures compared to the two control cohorts, indicating immune dysregulations and altered metabolic pathways.

We hypothesize that the initial viral infection may have caused immune-mediated structural changes of the microvasculature, potentially explaining the exercise-dependent fatigue and muscle pain.

Source: Tom AschmanEmanuel WylerOliver BaumAndreas HentschelFranziska LeglerCorinna PreusseLil Meyer-ArndtIvana BüttnerovaAlexandra FörsterDerya CengizLuiz Gustavo Teixeira AlvesJulia SchneiderClaudia KedorRebecca RustJudith Bellmann-StroblSanchin AminaaPeter VajkoczyHans-Hilmar GoebelMarkus LandthalerVictor CormanAndreas RoosFrank L. HeppnerHelena RadbruchFriedemann PaulCarmen ScheibenbogenWerner StenzelNora F. Dengler. Post-COVID syndrome is associated with capillary alterations, macrophage infiltration and distinct transcriptomic signatures in skeletal muscles.

Blood-brain barrier penetration of non-replicating SARS-CoV-2 and S1 variants of concern induce neuroinflammation which is accentuated in a mouse model of Alzheimer’s disease

Highlights:

• Two models of SARS-CoV-2 and all S1 protein Variants of Concern readily cross the BBB.
• The SARS-CoV-2 pseudovirus is taken up by microglia and induce neuroinflammation.
• The S1-induced neuroinflammation is exacerbated in a mouse model of Alzheimer’s disease.

Abstract:

COVID-19 and especially Long COVID are associated with severe CNS symptoms and may place persons at risk to develop long-term cognitive impairments. Here, we show that two non-infective models of SARS-CoV-2 can cross the blood–brain barrier (BBB) and induce neuroinflammation, a major mechanism underpinning CNS and cognitive impairments, even in the absence of productive infection. The viral models cross the BBB by the mechanism of adsorptive transcytosis with the sugar N-acetylglucosamine being key. The delta and omicron variants cross the BB B faster than the other variants of concern, with peripheral tissue uptake rates also differing for the variants. Neuroinflammation induced by icv injection of S1 protein was greatly enhanced in young and especially in aged SAMP8 mice, a model of Alzheimer’s disease, whereas sex and obesity had little effect.

Source: Erickson MA, Logsdon AF, Rhea EM, Hansen KM, Holden SJ, Banks WA, Smith JL, German C, Farr SA, Morley JE, Weaver RR, Hirsch AJ, Kovac A, Kontsekova E, Baumann KK, Omer MA, Raber J. Blood-brain barrier penetration of non-replicating SARS-CoV-2 and S1 variants of concern induce neuroinflammation which is accentuated in a mouse model of Alzheimer’s disease. Brain Behav Immun. 2023 Jan 20;109:251-268. doi: 10.1016/j.bbi.2023.01.010. Epub ahead of print. PMID: 36682515; PMCID: PMC9867649. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9867649/ (Full text)

Inflammation-associated gut microbiome in postacute sequelae of SARS-CoV-2 points towards new therapeutic targets

We read with interest the recent report by Liu et al1 describing faecal microbiome differences with postacute sequelae of SARS-CoV-2 (PASC), commonly referred to as ‘Long-COVID’. We have previously reported elevated levels of SARS-CoV-2-specific T cells with PASC compared with resolved COVID-19 (RC; no lingering symptoms at the time of sample collection) that correlated with increased levels of the inflammatory marker IL-6, suggesting that elevated inflammation in PASC may be related to immune response to residual virus.2 Although several studies have reported gut microbiome differences during acute COVID-19,3 PASC has received less attention. We, thus, sought to characterise gut microbiome differences in PASC versus RC using faecal samples from our study2 and to relate these differences to inflammation.

The faecal microbiome was evaluated using 16S rRNA gene sequencing. Plasma levels of inflammatory markers IL-6 and C reactive protein (CRP) were measured with ELISA (see online supplemental methods). Cohort information is in table 1. IL-6 and CRP were elevated with PASC (figure 1A). Gut microbiome composition did not significantly differ between the PASC and RC cohorts (PERMANOVA; p=0.087; figure 1B), but did correlate with IL-6 and CRP levels (Adonis; IL-6 p=0.03; CRP p=0.01). IL-6 and CRP also correlated with PC1 from a principal coordinates analysis (figure 1C,D), suggesting a relationship between microbiome composition and inflammation in PASC. Using SELBAL,4 which identifies ratios or ‘Balances’ of microbes that can differentiate between groups, we found that the faecal microbiomes of individuals with PASC had a lower ratio of an amplicon sequence variant (ASV) highly related to Faecalibacterium prausnitzii over ASVs related to species in the genus Bacteroides (B. doreiB. massiliensis and B. thetaiotaomicron) (figure 1E), which provided an area under the curve (AUC) of 0.863 for differentiating individuals with PASC from RC. Balance values also negatively correlated with IL-6 (r=−0.44, p=0.01). These microbiome differences are consistent with Liu et al,1 who also reported higher levels of Bacteroides (B. vulgatus specifically) and lower F. prausnitzii with PASC. Liu et al also reported higher Ruminococcus gnavus with PASC, and lower Collinsella aerofaciens, and Blautia obeum. Interestingly, an ASV highly related to R. gnavus (100% identity over V4 read) correlated positively with IL-6 and ASVs related to F. prausnitzii (98.7% ID), C. aerofaciens (100% ID) and B. obeum (100% ID) all negatively correlated with IL-6 and/or CRP levels in our study (online supplemental table 1). Thus, our results are consistent with those of Liu et al and extend their findings by showing associations between the microbiome and markers of systemic inflammation.

Read the rest of this letter HERE.

Source: Carneiro VL, Littlefield KM, Watson R, Palmer BE, Lozupone C. Inflammation-associated gut microbiome in postacute sequelae of SARS-CoV-2 points towards new therapeutic targets. Gut. 2023 Jan 30:gutjnl-2022-328757. doi: 10.1136/gutjnl-2022-328757. Epub ahead of print. PMID: 36717218. https://gut.bmj.com/content/early/2023/01/29/gutjnl-2022-328757 (Full text)

Assessment of short- and long-term functionality and quality of life in patients with post-acute COVID-19 syndrome

Abstract:

Background: Although the number of new cases of coronavirus 2019 (COVID-19) has been drastically reduced worldwide, patients who demonstrate long-term symptoms need more attention from health systems, as these symptoms can negatively affect functionality and quality of life.

Objective: To evaluate muscle function and quality of life at 3, 6, 9 and 12 months in patients with post-acute COVID-19 syndrome and to assess their associations with general fatigue and lung function.

Methods: This observational and longitudinal study evaluated patients with post-acute COVID-19 syndrome. Participants were subjected to the following evaluations: Short Form-36; handgrip strength; Functional Assessment of Chronic Illness Therapy-Fatigue scale; and spirometry.

Results: Among the 350 participants who were evaluated in the third month, 74.6%, 61.4% and 45.4% reported general fatigue, dyspnoea and cough, respectively. In the comparisons between the third month and the sixth month, there were significant increases in Functional Assessment of Chronic Illness Therapy-Fatigue scale, pulmonary function and several Short Form-36 domains. In the comparisons between the sixth month and the ninth month, there was a significant increase only in the social functioning domain of the Short Form-36. In the comparisons between the ninth month and the twelfth month, there was an increase only in some Short Form-36 domains. Significant correlations were observed between the Short Form-36 domains with Functional Assessment of Chronic Illness Therapy-Fatigue scale, handgrip strength and pulmonary function.

Conclusion: In patients with post-acute COVID-19 syndrome, there was a progressive improvement in quality of life, general fatigue and pulmonary function during the 12 months of follow-up, with this improvement being more pronounced in the first 6 months. There was a relationship between functionality and quality of life in these patients.

Source: de Azevedo Vieira JE, Mafort TT, Monnerat LB, da Cal MS, Ghetti ATA, Lopes AJ. Assessment of short- and long-term functionality and quality of life in patients with post-acute COVID-19 syndrome. J Back Musculoskelet Rehabil. 2023 Feb 2. doi: 10.3233/BMR-220308. Epub ahead of print. PMID: 36776041. https://content.iospress.com/articles/journal-of-back-and-musculoskeletal-rehabilitation/bmr220308 (Full text)

Unfavorable Outcome and Long-Term Sequelae in Cases with Severe COVID-19

Abstract:

Emerging evidence shows that individuals with COVID-19 who survive the acute phase of illness may experience lingering symptoms in the following months. There is no clear indication as to whether these symptoms persist for a short time before resolving or if they persist for a long time. In this review, we will describe the symptoms that persist over time and possible predictors in the acute phase that indicate long-term persistence.
Based on the literature available to date, fatigue/weakness, dyspnea, arthromyalgia, depression, anxiety, memory loss, slowing down, difficulty concentrating and insomnia are the most commonly reported persistent long-term symptoms. The extent and persistence of these in long-term follow-up is not clear as there are still no quality studies available.
The evidence available today indicates that female subjects and those with a more severe initial disease are more likely to suffer permanent sequelae one year after the acute phase. To understand these complications, and to experiment with interventions and treatments for those at greater risk, we must first understand the physio-pathological mechanisms that sustain them.
Source: Fabbri A, Voza A, Riccardi A, Vanni S, De Iaco F on behalf of the Study & Research Center of the Italian Society of Emergency Medicine (SIMEU). Unfavorable Outcome and Long-Term Sequelae in Cases with Severe COVID-19. Viruses. 2023; 15(2):485. https://doi.org/10.3390/v15020485 (Full text)

Role of the MicroRNAs in the Pathogenic Mechanism of Painful Symptoms in Long COVID: Systematic Review

Abstract:

The ongoing pandemic of COVID-19 has caused more than 6.7 million tragic deaths, plus, a large percentage of people who survived it present a myriad of chronic symptoms that last for at least 6 months; this has been named as long COVID. Some of the most prevalent are painful symptoms like headache, joint pain, migraine, neuropathic-like pain, fatigue and myalgia. MicroRNAs are small non-coding RNAs that regulate genes, and their involvement in several pathologies has been extensively shown. A deregulation of miRNAs has been observed in patients with COVID-19.
The objective of the present systematic review was to show the prevalence of chronic pain-like symptoms of patients with long COVID and based on the expression of miRNAs in patients with COVID-19, and to present a proposal on how they may be involved in the pathogenic mechanisms of chronic pain-like symptoms.
A systematic review was carried out in online databases for original articles published between March 2020 to April 2022; the systematic review followed the PRISMA guidelines, and it was registered in PROSPERO with registration number CRD42022318992. A total of 22 articles were included for the evaluation of miRNAs and 20 regarding long COVID; the overall prevalence of pain-like symptoms was around 10 to 87%, plus, the miRNAs that were commonly up and downregulated were miR-21-5p, miR-29a,b,c-3p miR-92a,b-3p, miR-92b-5p, miR-126-3p, miR-150-5p, miR-155-5p, miR-200a, c-3p, miR-320a,b,c,d,e-3p, and miR-451a.
The molecular pathways that we hypothesized to be modulated by these miRNAs are the IL-6/STAT3 proinflammatory axis and the compromise of the blood–nerve barrier; these two mechanisms could be associated with the prevalence of fatigue and chronic pain in the long COVID population, plus they could be novel pharmacological targets in order to reduce and prevent these symptoms.
Source: Reyes-Long S, Cortés-Altamirano JL, Bandala C, Avendaño-Ortiz K, Bonilla-Jaime H, Bueno-Nava A, Ávila-Luna A, Sánchez-Aparicio P, Clavijo-Cornejo D, Dotor-LLerena AL, Cabrera-Ruiz E, Alfaro-Rodríguez A. Role of the MicroRNAs in the Pathogenic Mechanism of Painful Symptoms in Long COVID: Systematic Review. International Journal of Molecular Sciences. 2023; 24(4):3574. https://doi.org/10.3390/ijms24043574 https://www.mdpi.com/1422-0067/24/4/3574 (Full text)

Long COVID could become a widespread post-pandemic disease? A debate on the organs most affected

Abstract:

Long COVID is an emerging problem in the current health care scenario. It is a syndrome with common symptoms of shortness of breath, fatigue, cognitive dysfunction, and other conditions that have a high impact on daily life. They are fluctuating or relapsing states that occur in patients with a history of SARS-CoV-2 infection for at least 2 months. They are usually conditions that at 3 months after onset cannot be explained by an alternative diagnosis. Currently very little is known about this syndrome.

A thorough review of the literature highlights that the cause is attributable to deposits of tau protein. Massive phosphorylation of tau protein in response to SARS-CoV-2 infection occurred in brain samples from autopsies of people previously affected with COVID-19. The neurological disorders resulting from this clinical condition are termed tauopathies and can give different pathological symptoms depending on the involved anatomical region of the brain.

Peripheral small-fiber neuropathies are also evident among patients with Long COVID leading to fatigue, which is the main symptom of this syndrome. Certainly more research studies could confirm the association between tau protein and Long COVID by defining the main role of tau protein as a biomarker for the diagnosis of this syndrome that is widespread in the post-pandemic period.

Source: Ferrara, F., Zovi, A., Masi, M. et al. Long COVID could become a widespread post-pandemic disease? A debate on the organs most affected. Naunyn-Schmiedeberg’s Arch Pharmacol (2023). https://doi.org/10.1007/s00210-023-02417-5 https://link.springer.com/article/10.1007/s00210-023-02417-5 (Full text)

Vaccination status and long COVID symptoms in patients discharged from hospital

Abstract:

Effective vaccination against coronavirus mitigates the risk of hospitalisation and mortality; however, it is unclear whether vaccination status influences long COVID symptoms in patients who require hospitalisation. The available evidence is limited to outpatients with mild disease.

Here, we evaluated 412 patients (age: 60 ± 16 years, 65% males) consecutively admitted to two Hospitals in Brazil due to confirmed coronavirus disease 2019 (COVID-19). Compared with patients with complete vaccination (n = 185) before infection or hospitalisation, those with no or incomplete vaccination (n = 227) were younger and had a lower frequency of several comorbidities.

Data during hospitalisation revealed that the no or incomplete vaccination group required more admissions to the intensive care unit (ICU), used more corticosteroids, and had higher rates of pulmonary embolism or deep venous thrombosis than the complete vaccination group. Ninety days after hospital discharge, patients with no or incomplete vaccination presented a higher frequency of symptoms (≥ 1) than patients with complete vaccination (40 vs. 27%; p = 0.013).

After adjusting for confounders, no or incomplete vaccination (odds ratio [OR] 1.819; 95% confidence interval [CI] 1.175-2.815), female sex (OR 2.435; 95% CI 1.575-3.764) and ICU admission during hospitalisation (OR 1.697; 95% CI 1.062-2.712) were independently associated with ≥ 1 symptom 90 days after hospital discharge.

In conclusion, even in patients with severe COVID-19, vaccination mitigates the probability of long COVID symptoms.

Source: Nascimento TCDC, do Valle Costa L, Ruiz AD, Ledo CB, Fernandes VPL, Cardoso LF, Junior JMV, Saretta R, Kalil-Filho R, Drager LF. Vaccination status and long COVID symptoms in patients discharged from hospital. Sci Rep. 2023 Feb 11;13(1):2481. doi: 10.1038/s41598-023-28839-y. PMID: 36774419; PMCID: PMC9922040. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9922040/ (Full text)

Neurological Manifestations of Long COVID: A Single-Center One-Year Experience

Abstract:

Purpose: We report our single-center experience on the neurological manifestations of long COVID.

Patients and methods: This is a retrospective observational study. All consecutive patients referred to the neurological long COVID outpatient clinic of our institute from January 21 2021 to December 9 2021 underwent a general neurological objective examination. Treatments and investigations (brain MRI, neuropsychological evaluation, or others) were prescribed on an individual basis as per standard clinical practice. A follow-up visit was performed when appropriate. Descriptive statistics were presented as absolute and relative frequencies for categorical variables and as means, median, and ranges for continuous variables.

Results: One hundred and three patients were visited (mean age 50.5 ±36 years, 62 females). The average time from acute COVID-19 infection to the first visit to our outpatient clinic was 243 days. Most patients presented with a mild form of acute COVID-19, with only 24 cases requiring hospitalization. The neurological symptoms mostly (n=70/103, 68%) started during the acute phase (before a negative swab for SARS-CoV-2). The most frequent acute manifestations reported, which lately became persistent, were fatigue (n=58/103, 56%), olfactory/taste dysfunction (n=58/103, 56%), headache (n=47/103, 46%), cognitive disorders (n=46/103, 45%), sleep disorders (n=30/103, 29%), sensitivity alterations (n=29/103, 28%), and dizziness (n=7/103, 7%). Tremor was also reported (n=8/103, 7%). Neuropsychological evaluation was performed in 30 patients and revealed alterations in executive functions (n=6/30, 20%), memory (n=11/30, 37%), with pathological depressive (n=9/30, 30%) and anxiety (n=8/30, 27%) scores. Brain MRIs have been performed in 41 cases, revealing nonspecific abnormal findings only in 4 cases. Thirty-six patients underwent a follow-up, where a general improvement was observed but rarely (n=2/36) a complete recovery.

Conclusion: The majority of patients presenting persistent neurological symptoms (most frequently fatigue, cognitive disorders, and olfactory dysfunctions) developed a previous mild form of COVID-19. Further studies are required to develop therapeutic strategies.

Source: Taruffi L, Muccioli L, Mitolo M, Ferri L, Descovich C, Mazzoni S, Michelucci R, Lodi R, Liguori R, Cortelli P, Tonon C, Bisulli F. Neurological Manifestations of Long COVID: A Single-Center One-Year Experience. Neuropsychiatr Dis Treat. 2023 Feb 3;19:311-319. doi: 10.2147/NDT.S387501. PMID: 36761395; PMCID: PMC9904212. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9904212/ (Full text)

Compliance challenges in a longitudinal COVID-19 cohort using wearables for continuous monitoring

Abstract:

Background: Wearables to Investigate the Long Term Cardiovascular and Behavioral Impacts of COVID-19 (WEAICOR) study is a prospective observational study using continuous monitoring to detect and analyze biometrics. Compliance to wearables was a major challenge when conducting the study and was crucial for the results.

Objective: The aim of this study is to evaluate patients’ compliance to wearable wristbands and determinants of compliance in a prospective COVID-19 cohort.

Methods: Biostrap wearable device was used to monitor participants’ biometric data. Compliance was calculated by dividing the total number of days in which transmissions were sent by the total number of days in the study. Univariate correlation was performed between compliance, days in the study and age, BMI, sex, symptom severity, and number of complications/comorbidites as independent variables. Also, multivariate linear regression was then performed with days in the study as a dependent variable to assess the power of different parameters in determining days in the study.

Results: On hundred twenty-two patients were included in the study. Patients were on average 43 years old and 32% were female. Age was found to be correlated with compliance (r=0.23, P=0.01). In addition, age (r=0.30, P=0.001), BMI (r=0.19, P=0.03) and severity of symptoms (r=0.19, P=0.03) were found to be correlated with days spent in the study. On multivariate analysis with days spent in the study as a dependent variable, only increased age was a significant determinant of compliance with wearables (adjusted R2 = 0.1, β = 1.6, P= 0.01).

Conclusions: Compliance is a major obstacle in remote monitoring studies and the reasons for a lack thereof are multifactorial. Patient factors such as age, in addition to environmental factors can affect compliance to wearables.

Source: Mekhael M, Ho C, Noujaim C, Assaf A, Younes H, El Hajjar AH, Chaudhry HA, Lanier B, Chouman N, Makan N, Shan B, Zhang Y, Dagher L, Kreidieh O, Marrouche N, Donnellan E. Compliance challenges in a longitudinal COVID-19 cohort using wearables for continuous monitoring. J Med Internet Res. 2023 Jan 6. doi: 10.2196/43134. Epub ahead of print. PMID: 36763647. https://preprints.jmir.org/preprint/43134/accepted (Full text available as PDF file)