Laboratory parameters related to disease severity and physical performance after reconvalescence of acute COVID-19 infection.

Research into the molecular basis of disease trajectory and Long-COVID is important to get insights toward underlying pathophysiological processes. The objective of this study was to investigate inflammation-mediated changes of metabolism in patients with acute COVID-19 infection and throughout a one-year follow up period. The study enrolled 34 patients with moderate to severe COVID-19 infection admitted to the University Clinic of Innsbruck in early 2020. The dynamics of multiple laboratory parameters (including inflammatory markers [C-reactive protein (CRP), interleukin-6 (IL-6), neopterin] as well as amino acids [tryptophan (Trp), phenylalanine (Phe) and tyrosine (Tyr)], and parameters of iron and vitamin B metabolism) was related to disease severity and patients' physical performance. Also, symptom load during acute illness and at approximately 60 days (FU1), and one year after symptom onset (FU2) were monitored and related with changes of the investigated laboratory parameters: During acute infection many investigated laboratory parameters were elevated (e.g., inflammatory markers, ferritin, kynurenine, phenylalanine) and enhanced tryptophan catabolism and phenylalanine accumulation were found. At FU2 nearly all laboratory markers had declined back to reference ranges. However, kynurenine/tryptophan ratio (Kyn/Trp) and the phenylalanine/tyrosine ratio (Phe/Tyr) were still exceeding the 95th percentile of healthy controls in about two thirds of our cohort at FU2. Lower tryptophan concentrations were associated with B vitamin availability (during acute infection and at FU1), patients with lower vitamin B12 levels at FU1 had a prolonged and more severe impairment of their physical functioning ability. Patients who had fully recovered (ECOG 0) presented with higher concentrations of iron parameters (ferritin, hepcidin, transferrin) and amino acids (phenylalanine, tyrosine) at FU2 compared to patients with restricted ability to work. Persistent symptoms at FU2 were tendentially associated with IFN-γ related parameters. Women were affected by long-term symptoms more frequently. Conclusively, inflammation-mediated biochemical changes appear to be related to symptoms of patients with acute and Long Covid.

Higher COVID-19 pneumonia risk associated with anti-IFN-α than with anti-IFN-ω auto-Abs in children.

We found that 19 (10.4%) of 183 unvaccinated children hospitalized for COVID-19 pneumonia had autoantibodies (auto-Abs) neutralizing type I IFNs (IFN-α2 in 10 patients: IFN-α2 only in three, IFN-α2 plus IFN-ω in five, and IFN-α2, IFN-ω plus IFN-ß in two; IFN-ω only in nine patients). Seven children (3.8%) had Abs neutralizing at least 10 ng/ml of one IFN, whereas the other 12 (6.6%) had Abs neutralizing only 100 pg/ml. The auto-Abs neutralized both unglycosylated and glycosylated IFNs. We also detected auto-Abs neutralizing 100 pg/ml IFN-α2 in 4 of 2,267 uninfected children (0.2%) and auto-Abs neutralizing IFN-ω in 45 children (2%). The odds ratios (ORs) for life-threatening COVID-19 pneumonia were, therefore, higher for auto-Abs neutralizing IFN-α2 only (OR [95% CI] = 67.6 [5.7-9,196.6]) than for auto-Abs neutralizing IFN-ω only (OR [95% CI] = 2.6 [1.2-5.3]). ORs were also higher for auto-Abs neutralizing high concentrations (OR [95% CI] = 12.9 [4.6-35.9]) than for those neutralizing low concentrations (OR [95% CI] = 5.5 [3.1-9.6]) of IFN-ω and/or IFN-α2.

Body Composition and Physical Performance 1 Year After COVID-19.

OBJECTIVE: Long-term consequences after COVID-19 include physical complaints, which may impair physical recovery and quality of life. DESIGN: We assessed body composition and physical ability in patients 12 months after COVID-19. Consecutively recruited patients recovering from mild to severe COVID-19 were assessed using bioelectrical impedance analysis, 6-min-walk test, additional scales for physical performance and health-related quality of life. RESULTS: Overall physical recovery was good (i.e., Glasgow Outcome Scale-Extended ≥7 in 96%, Modified Rankin Scale ≤1 in 87%, Eastern Cooperative Oncology Group ≤1 in 99%). Forty-four percent of the 69 patients experienced a significant body mass index increase in the year after COVID-19 (≥1 kg/m 2 ), whereas skeletal muscle mass index was reduced in only 12%. Patients requiring intensive care treatment ( n = 15, 22%) during acute COVID-19 more often had a body mass index increase ( P = 0.002), worse 6-min-walk test-performance ( P = 0.044), and higher body fat mass ( P = 0.030) at the 1-yr follow-up when compared with patients with mild ( n = 22, 32%) and moderate ( n = 32, 46%) acute COVID-19. Body mass index increase was also more frequent in patients who had no professional rehabilitation ( P = 0.014). CONCLUSIONS: Although patients with severe COVID-19 had increased body mass index and body fat and performed worse in physical outcome measures 1 yr after COVID-19, overall physical recovery was satisfying. Translating these findings to variants beyond the Alpha strain of severe acute respiratory syndrome coronavirus 2 virus needs further studies.

SARS-CoV-2 activates the TLR4/MyD88 pathway in human macrophages: A possible correlation with strong pro-inflammatory responses in severe COVID-19.

Background: Toll-like receptors (TLRs) play a pivotal role in the immunologic response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Exaggerated inflammatory response of innate immune cells, however, may drive morbidity and death in Coronavirus disease 19 (COVID-19). Objective: We investigated the engagement of SARS-CoV-2 with TLR4 in order to better understand how to tackle hyperinflammation in COVID-19. Methods: We combined RNA-sequencing data of human lung tissue and of bronchoalveolar lavage fluid cells derived from COVID-19 patients with functional studies in human macrophages using SARS-CoV-2 spike proteins and viable SARS-CoV-2. Pharmacological inhibitors as well as gene editing with CRISPR/Cas9 were used to delineate the signalling pathways involved. Results: We found TLR4 to be the most abundantly upregulated TLR in human lung tissue irrespective of the underlying pathology. Accordingly, bronchoalveolar lavage fluid cells from patients with severe COVID-19 showed an NF-κB-pathway dominated immune response, whereas they were mostly defined by type I interferon signalling in moderate COVID-19. Mechanistically, we found the Spike ectodomain, but not receptor binding domain monomer to induce TLR4-dependent inflammation in human macrophages. By using pharmacological inhibitors as well as CRISPR/Cas9 deleted macrophages, we identify SARS-CoV-2 to engage canonical TLR4-MyD88 signalling. Importantly, we demonstrate that TLR4 blockage prevents exaggerated inflammatory responses in human macrophages infected with different SARS-CoV-2 variants, including immune escape variants B.1.1.7.-E484K and B.1.1.529 (omicron). Conclusion: Our study critically extends the current knowledge on TLR-mediated hyperinflammatory responses to SARS-CoV-2 in human macrophages, paving the way for novel approaches to tackle severe COVID-19. Take-home message: Our study combining human lung transcriptomics with functional studies in human macrophages clearly supports the design and development of TLR4 - directed therapeutics to mitigate hyperinflammation in severe COVID-19.

Distinct smell and taste disorder phenotype of post-acute COVID-19 sequelae.

PURPOSE: Olfactory dysfunction (OD) commonly accompanies coronavirus disease 2019 (COVID-19). We investigated the kinetics of OD resolution following SARS-CoV-2 infection (wild-type and alpha variant) and its impact on quality of life, physical and mental health. METHODS: OD prevalence was assessed in an ambulatory COVID-19 survey (n = 906, ≥ 90 days follow-up) and an observational cohort of ambulatory and hospitalized individuals (n = 108, 360 days follow-up). Co-occurrence of OD with other symptoms and effects on quality of life, physical and mental health were analyzed by multi-dimensional scaling, association rule mining and semi-supervised clustering. RESULTS: Both in the ambulatory COVID-19 survey study (72%) and the observational ambulatory and hospitalized cohort (41%) self-reported OD was frequent during acute COVID-19. Recovery from self-reported OD was slow (survey: median 28 days, observational cohort: 90 days). By clustering of the survey data, we identified a predominantly young, female, comorbidity-free group of convalescents with persistent OD and taste disorders (median recovery: 90 days) but low frequency of post-acute fatigue, respiratory or neurocognitive symptoms. This smell and taste disorder cluster was characterized by a high rating of physical performance, mental health, and quality of life as compared with convalescents affected by prolonged fatigue or neurocognitive complaints. CONCLUSION: Our results underline the heterogeneity of post-acute COVID-19 sequelae calling for tailored management strategies. The persistent smell and taste disorder phenotype is characterized by good clinical, physical, and mental recovery and may pose a minor challenge for public health. STUDY REGISTRATION: ClinicalTrials.gov: NCT04661462 (survey study), NCT04416100 (observational cohort).

Association of High-Sensitivity Cardiac Troponin T With 30-Day and 5-Year Mortality After Cardiac Surgery.

BACKGROUND: The relevance of perioperative myocardial injury (PMI) after cardiac surgery for 30-day mortality and long-term survival remains to be determined. OBJECTIVES: This study assessed the association of PMI after cardiac surgery, reflected by postoperative troponin release, with 30-day mortality and long-term survival after: 1) coronary artery bypass grafting (CABG); 2) isolated aortic valve replacement (AVR) surgery; and 3) all other cardiac surgeries. METHODS: A consecutive cohort of 8,292 patients undergoing cardiac surgery with serial perioperative high-sensitivity cardiac troponin T (hs-cTnT) measurements was retrospectively analyzed. The relationship between postoperative hs-cTnT release and 30-day mortality or 5-year mortality was analyzed after adjustment with EuroSCORE II using a Cox proportional hazards model. hs-cTnT thresholds for 30-day and 5-year mortality were determined for isolated CABG (32.3%), AVR (14%), and other cardiac surgery (53.8%). RESULTS: High postoperative hs-cTnT levels were associated with higher 30-day mortality but not 5-year mortality. In CABG, median peak concentration of postoperative hs-cTnT was 1,044 ng/L, in AVR it was 502 ng/L, and in other cardiac surgery it was 1,110 ng/L. hs-cTnT thresholds defining mortality-associated PMI were as follows: for CABG, 2,385 ng/L (170× the upper reference limit of normal in a seemingly healthy population [URL]); for AVR, 568 ng/L (41× URL); and for other cardiac procedures, 1,873 ng/L (134× URL). hs-cTnT levels above the cutoffs resulted in an HR for 30-day mortality for CABG of 12.56 (P < 0.001), for AVR of 4.44 (P = 0.004), and for other cardiac surgery of 3.97 (P < 0.001). CONCLUSIONS: PMI reflected by perioperative hs-cTnT release is associated with the expected 30-day mortality but not 5-year mortality. Postoperative hs-cTnT cutoffs to identify survival-relevant PMI are higher than suggested in current definitions.

The negative adipogenesis regulator Dlk1 is transcriptionally regulated by Ifrd1 (TIS7) and translationally by its orthologue Ifrd2 (SKMc15).

Delta-like homolog 1 (Dlk1), an inhibitor of adipogenesis, controls the cell fate of adipocyte progenitors. Experimental data presented here identify two independent regulatory mechanisms, transcriptional and translational, by which Ifrd1 (TIS7) and its orthologue Ifrd2 (SKMc15) regulate Dlk1 levels. Mice deficient in both Ifrd1 and Ifrd2 (dKO) had severely reduced adipose tissue and were resistant to high-fat diet-induced obesity. Wnt signaling, a negative regulator of adipocyte differentiation, was significantly upregulated in dKO mice. Elevated levels of the Wnt/ß-catenin target protein Dlk1 inhibited the expression of adipogenesis regulators Pparg and Cebpa, and fatty acid transporter Cd36. Although both Ifrd1 and Ifrd2 contributed to this phenotype, they utilized two different mechanisms. Ifrd1 acted by controlling Wnt signaling and thereby transcriptional regulation of Dlk1. On the other hand, distinctive experimental evidence showed that Ifrd2 acts as a general translational inhibitor significantly affecting Dlk1 protein levels. Novel mechanisms of Dlk1 regulation in adipocyte differentiation involving Ifrd1 and Ifrd2 are based on experimental data presented here.

Persistent Symptoms and IFN-γ-Mediated Pathways after COVID-19.

After COVID-19, patients have reported various complaints such as fatigue, neurological symptoms, and insomnia. Immune-mediated changes in amino acid metabolism might contribute to the development of these symptoms. Patients who had had acute, PCR-confirmed COVID-19 infection about 60 days earlier were recruited within the scope of the prospective CovILD study. We determined the inflammatory parameters and alterations in tryptophan and phenylalanine metabolism in 142 patients cross-sectionally. Symptom persistence (pain, gastrointestinal symptoms, anosmia, sleep disturbance, and neurological symptoms) and patients' physical levels of functioning were recorded. Symptoms improved in many patients after acute COVID-19 (n = 73, 51.4%). Still, a high percentage of patients had complaints, and women were affected more often. In many patients, ongoing immune activation (as indicated by high neopterin and CRP concentrations) and enhanced tryptophan catabolism were found. A higher phenylalanine to tyrosine ratio (Phe/Tyr) was found in women with a lower level of functioning. Patients who reported improvements in pain had lower Phe/Tyr ratios, while patients with improved gastrointestinal symptoms presented with higher tryptophan and kynurenine values. Our results suggest that women have persistent symptoms after COVID-19 more often than men. In addition, the physical level of functioning and the improvements in certain symptoms appear to be associated with immune-mediated changes in amino acid metabolism.

Interferon-gamma Mediated Metabolic Pathways in Hospitalized Patients During Acute and Reconvalescent COVID-19.

Background: Fatigue, sleep disturbance, and neurological symptoms during and after COVID-19 are common and might be associated with inflammation-induced changes in tryptophan (Trp) and phenylalanine (Phe) metabolism. Aim: This pilot study investigated interferon gamma inducible biochemical pathways (namely Trp catabolism, neopterin, tyrosine [Tyr], and nitrite formation) during acute COVID-19 and reconvalescence. Patients and methods: Thirty one patients with moderate to severe COVID-19 admitted to the University Hospital of Innsbruck in early 2020 (March-May) were followed up. Neurotransmitter precursors Trp, Phe, Tyr as well as kynurenine (Kyn), neopterin, nitrite, and routine laboratory parameters were analyzed during acute infection and at a follow-up (FU) 60 days thereafter. Clinical symptoms of patients (neurological symptoms, fatigue, sleep disturbance) were recorded and associations with concentrations of laboratory parameters investigated. Results and conclusion: Almost half of the patients suffered from neurological symptoms (48.4%), the majority of patients experienced sleep difficulties (56.7%) during acute COVID-19. Fatigue was present in nearly all patients. C-reactive protein (CRP), interleukin-6 (IL-6), neopterin, Kyn, Phe concentrations were significantly increased, and Trp levels depleted during acute COVID-19. Patients with sleep impairment and neurological symptoms during acute illness presented with increased CRP and IL-6 concentrations, Trp levels were lower in patients with sleep disturbance. In general, inflammatory markers declined during reconvalescence. A high percentage of patients suffered from persistent symptoms at FU (neurological symptoms: 17.2%, fatigue: 51.7%, sleeping disturbance: 34.5%) and had higher CRP concentrations. Nitrite and Phe levels were lower in patients with sleeping difficulties at FU and Kyn/Trp ratio, as indicator of IDO activity, was significantly lower in patients with neurological symptoms compared to patients without them at FU. In summary, inflammation induced alterations of amino acid metabolism might be related to acute and persisting symptoms of COVID-19.

Toll-Like Receptor 3 Mediates Aortic Stenosis Through a Conserved Mechanism of Calcification.

BACKGROUND: Calcific aortic valve disease (CAVD) is characterized by a phenotypic switch of valvular interstitial cells to bone-forming cells. Toll-like receptors (TLRs) are evolutionarily conserved pattern recognition receptors at the interface between innate immunity and tissue repair. Type I interferons (IFNs) are not only crucial for an adequate antiviral response but also implicated in bone formation. We hypothesized that the accumulation of endogenous TLR3 ligands in the valvular leaflets may promote the generation of osteoblast-like cells through enhanced type I IFN signaling. METHODS: Human valvular interstitial cells isolated from aortic valves were challenged with mechanical strain or synthetic TLR3 agonists and analyzed for bone formation, gene expression profiles, and IFN signaling pathways. Different inhibitors were used to delineate the engaged signaling pathways. Moreover, we screened a variety of potential lipids and proteoglycans known to accumulate in CAVD lesions as potential TLR3 ligands. Ligand-receptor interactions were characterized by in silico modeling and verified through immunoprecipitation experiments. Biglycan (Bgn), Tlr3, and IFN-α/ß receptor alpha chain (Ifnar1)-deficient mice and a specific zebrafish model were used to study the implication of the biglycan (BGN)-TLR3-IFN axis in both CAVD and bone formation in vivo. Two large-scale cohorts (GERA [Genetic Epidemiology Research on Adult Health and Aging], n=55 192 with 3469 aortic stenosis cases; UK Biobank, n=257 231 with 2213 aortic stenosis cases) were examined for genetic variation at genes implicated in BGN-TLR3-IFN signaling associating with CAVD in humans. RESULTS: Here, we identify TLR3 as a central molecular regulator of calcification in valvular interstitial cells and unravel BGN as a new endogenous agonist of TLR3. Posttranslational BGN maturation by xylosyltransferase 1 (XYLT1) is required for TLR3 activation. Moreover, BGN induces the transdifferentiation of valvular interstitial cells into bone-forming osteoblasts through the TLR3-dependent induction of type I IFNs. It is intriguing that Bgn-/-, Tlr3-/-, and Ifnar1-/- mice are protected against CAVD and display impaired bone formation. Meta-analysis of 2 large-scale cohorts with >300 000 individuals reveals that genetic variation at loci relevant to the XYLT1-BGN-TLR3-interferon-α/ß receptor alpha chain (IFNAR) 1 pathway is associated with CAVD in humans. CONCLUSIONS: This study identifies the BGN-TLR3-IFNAR1 axis as an evolutionarily conserved pathway governing calcification of the aortic valve and reveals a potential therapeutic target to prevent CAVD.

Tissue iron distribution in patients with anemia of inflammation: Results of a pilot study.

Anemia of inflammation (AI) is frequently present in subjects with inflammatory disorders, primarily caused by inflammation-driven iron retention in macrophages. So far, only limited data on qualitative and quantitative estimates of tissue iron retention in AI patients exist. We performed a prospective cohort study analyzing splenic, hepatic, pancreatic, and cardiac iron content with MRI-based R2*-relaxometry in AI patients, including subjects with concomitant true iron deficiency (AI+IDA) hospitalized between 05/2020-01/2022. Control groups were individuals without inflammation. Spleen R2* values in AI patients with ferritin ≤200 µg/L (AI+IDA) were comparable with those found in controls. In AI patients with ferritin >200 µg/L, spleen (47.6 s-1 vs. 19.3 s-1 , p < .001) and pancreatic R2* values (32.5 s-1 vs. 24.9 s-1 , p = .011) were significantly higher compared with controls, while liver and heart R2*-values did not differ. Higher spleen R2* values were associated with higher ferritin, hepcidin, CRP, and IL-6 concentrations. Spleen R2* values normalized in AI patients after recovery (23.6 s-1 vs. 47.6 s-1 , p = .008), while no changes were found in patients with baseline AI+IDA. This is the first study investigating tissue iron distribution in patients with inflammatory anemia and AI with concomitant true iron deficiency. The results support the findings in animal models demonstrating iron retention in macrophages, which are primarily accumulating in the spleen under inflammatory conditions. MRI-related iron measurement may help to better characterize actual iron needs and to define better biomarker thresholds in the diagnosis of true ID in patients with AI. It may qualify as a useful diagnostic method to estimate the need for iron supplementation and to guide therapy.

Immunity of Heterologously and Homologously Boosted or Convalescent Individuals Against Omicron BA.1, BA.2, and BA.4/5 Variants.

BACKGROUND: The emerged severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variants BA.1, BA.2, and BA.4/5 demonstrate higher transmission and infection rates than previous variants of concern. To evaluate effectiveness of heterologous and homologous booster vaccination, we directly compared cellular and humoral immune responses as well as neutralizing capacity against replication-competent SARS-CoV-2 wild type, Delta, and Omicron variants BA.1, BA.2, and BA.4/5. METHODS: Peripheral blood mononuclear cells and serum samples from 137 participants were investigated, in 3 major groups. Individuals in the first group were vaccinated twice with ChAdOx1 and boosted with a messenger RNA (mRNA) vaccine (BNT162b2 or mRNA-1273); the second group included triple mRNA--vaccinated participants, and the third group, twice-vaccinated and convalescent individuals. RESULTS: Vaccination and convalescence resulted in the highest SARS-CoV-2-specific antibody levels, stronger T-cell responses, and best neutralization against wild type, Delta Omicron BA.2, and BA.4/5, while a combination of ChAdOx1 and BNT162b2 vaccination elevated neutralizing capacity against Omicron BA.1. In addition, heterologous booster regimens, compared with homologous regimens, showed higher efficacy against Omicron BA.2 as well as BA.4/5. CONCLUSIONS: We showed that twice-vaccinated and convalescent individuals demonstrated the strongest immunity against Omicron BA.2 and BA.4/5 variant, followed by those receiving heterologous and homologous booster vaccine regimens.

COVID-19 and its continuing burden after 12†months: a longitudinal observational prospective multicentre trial.

Background: Recovery trajectories from coronavirus disease 2019 (COVID-19) call for longitudinal investigation. We aimed to characterise the kinetics and status of clinical, cardiopulmonary and mental health recovery up to 1 year following COVID-19. Methods: Clinical evaluation, lung function testing (LFT), chest computed tomography (CT) and transthoracic echocardiography were conducted at 2, 3, 6 and 12 months after disease onset. Submaximal exercise capacity, mental health status and quality of life were assessed at 12 months. Recovery kinetics and patterns were investigated by mixed-effect logistic modelling, correlation and clustering analyses. Risk of persistent symptoms and cardiopulmonary abnormalities at the 1-year follow-up were modelled by logistic regression. Findings: Out of 145 CovILD study participants, 108 (74.5%) completed the 1-year follow-up (median age 56.5 years; 59.3% male; 24% intensive care unit patients). Comorbidities were present in 75% (n=81). Key outcome measures plateaued after 180 days. At 12 months, persistent symptoms were found in 65% of participants; 33% suffered from LFT impairment; 51% showed CT abnormalities; and 63% had low-grade diastolic dysfunction. Main risk factors for cardiopulmonary impairment included pro-inflammatory and immunological biomarkers at early visits. In addition, we deciphered three recovery clusters separating almost complete recovery from patients with post-acute inflammatory profile and an enrichment in cardiopulmonary residuals from a female-dominated post-COVID-19 syndrome with reduced mental health status. Conclusion: 1 year after COVID-19, the burden of persistent symptoms, impaired lung function, radiological abnormalities remains high in our study population. Yet, three recovery trajectories are emerging, ranging from almost complete recovery to post-COVID-19 syndrome with impaired mental health.

Persistent somatic symptoms are key to individual illness perception at one year after COVID-19 in a cross-sectional analysis of a prospective cohort study.

OBJECTIVE: Subjective illness perception (IP) can differ from physician's clinical assessment results. Herein, we explored patient's IP during coronavirus disease 2019 (COVID-19) recovery. METHODS: Participants of the prospective observation CovILD study (ClinicalTrials.gov: NCT04416100) with persistent somatic symptoms or cardiopulmonary findings one year after COVID-19 were analyzed (n = 74). Explanatory variables included demographic and comorbidity, COVID-19 course and one-year follow-up data of persistent somatic symptoms, physical performance, lung function testing, chest computed tomography and trans-thoracic echocardiography. Factors affecting IP (Brief Illness Perception Questionnaire) one year after COVID-19 were identified by regularized modeling and unsupervised clustering. RESULTS: In modeling, 33% of overall IP variance (R2) was attributed to fatigue intensity, reduced physical performance and persistent somatic symptom count. Overall IP was largely independent of lung and heart findings revealed by imaging and function testing. In clustering, persistent somatic symptom count (Kruskal-Wallis test: η2 = 0.31, p < .001), fatigue (η2 = 0.34, p < .001), diminished physical performance (χ2 test, Cramer V effect size statistic: V = 0.51, p < .001), dyspnea (V = 0.37, p = .006), hair loss (V = 0.57, p < .001) and sleep problems (V = 0.36, p = .008) were strongly associated with the concern, emotional representation, complaints, disease timeline and consequences IP dimensions. CONCLUSION: Persistent somatic symptoms rather than abnormalities in cardiopulmonary testing influence IP one year after COVID-19. Modifying IP represents a promising innovative approach to treatment of post-COVID-19 condition. Besides COVID-19 severity, individual IP should guide rehabilitation and psychological therapy decisions.

Pulmonary recovery from COVID-19 in patients with metabolic diseases: a longitudinal prospective cohort study.

The severity of coronavirus disease 2019 (COVID-19) is related to the presence of comorbidities including metabolic diseases. We herein present data from the longitudinal prospective CovILD trial, and investigate the recovery from COVID-19 in individuals with dysglycemia and dyslipidemia. A total of 145 COVID-19 patients were prospectively followed and a comprehensive clinical, laboratory and imaging assessment was performed at 60, 100, 180, and 360 days after the onset of COVID-19. The severity of acute COVID-19 and outcome at early post-acute follow-up were significantly related to the presence of dysglycemia and dyslipidemia. Still, at long-term follow-up, metabolic disorders were not associated with an adverse pulmonary outcome, as reflected by a good recovery of structural lung abnormalities in both, patients with and without metabolic diseases. To conclude, dyslipidemia and dysglycemia are associated with a more severe course of acute COVID-19 as well as delayed early recovery but do not impair long-term pulmonary recovery.

Interstitial Pulmonary Fibrosis and Extensive Dendriform Ossification with Persistent Viral Load: A Rare Presentation of Post-COVID-19 Condition in Need of Lung Transplantation.

The incidence, presentation, and predisposing factors of post-acute sequelae of COVID-19 (PASC) are currently poorly understood. Lung explants may provide a rare insight into terminal SARS-CoV-2-associated lung damage and its pathophysiology. A 62-year-old man presented with progressively worsening respiratory symptoms after recovering from mild COVID-19 3 months earlier. No underlying pulmonary comorbidities were reported. A chest CT revealed bilateral extensive ground-glass and reticular opacities, suspicious of pulmonary fibrosis. Despite initial high-dose glucocorticoid therapy, the interstitial lung disease progressed, and after exhausting all viable therapeutic options, bilateral lung transplantation was successfully conducted. Histological analysis revealed extensive end-stage interstitial fibrosis with diffuse dendriform ossification and bronchiolar and transitional cell metaplasia. Signs of interstitial remodeling such as an increased interstitial collagen deposition, a pathological accumulation of CD163+/CD206+ M2-polarized macrophages with an increased expression of phosphorylated ERK, and an increased density of CD105+ newly formed capillaries were observed. qRT-PCR and immunohistochemistry for SARS-CoV-2 N-protein in the endothelium of medium-sized vessels confirmed a persistence of SARS-CoV-2. Our findings highlight a highly unusual presentation of SARS-CoV-2-associated lung fibrosis, implying that incomplete viral clearance in the vascular compartment may play a vital pathophysiological role in the development of PASC.

Different calcification patterns of tricuspid and bicuspid aortic valves and their clinical impact.

OBJECTIVES: Mechanical strain plays a major role in the development of aortic calcification. We hypothesized that (i) valvular calcifications are most pronounced at the localizations subjected to the highest mechanical strain and (ii) calcification patterns are different in patients with bicuspid and tricuspid aortic valves. METHODS: Multislice computed tomography scans of 101 patients with severe aortic stenosis were analysed using a 3-dimensional post-processing software to quantify calcification of tricuspid aortic valves (n = 51) and bicuspid aortic valves (n = 50) after matching. RESULTS: Bicuspid aortic valves exhibited higher calcification volumes and increased calcification of the non-coronary cusp with significantly higher calcification of the free leaflet edge. The non-coronary cusp showed the highest calcium load compared to the other leaflets. Patients with annular calcification above the median had an impaired survival compared to patients with low annular calcification, whereas patients with calcification of the free leaflet edge above the median did not (P = 0.53). CONCLUSIONS: Calcification patterns are different in patients with aortic stenosis with bicuspid and tricuspid aortic valves. Patients with high annular calcification might have an impaired prognosis.

Correlation between structural heart disease and cardiac SARS-CoV-2 manifestations.

BACKGROUND: The prognosis of COVID-19 patients with cardiac involvement is unfavorable and it remains unknown which patients are at risk. The virus enters cells via its receptor angiotensin-converting enzyme 2 (ACE2). Myocardial ACE2 expression is increased in structural heart disease (SHD). We, therefore, aimed to analyze correlations between structural heart disease and cardiac SARS-CoV-2 manifestation. METHODS: The clinical course of COVID-19 in patients with structural heart disease was assessed in a prospective cohort of 152 patients. The primary endpoints consisted of hospitalization and survival. Cardiac tissue of 23 autopsy cases with lethal COVID-19 course was obtained and analyzed for (a) the presence of SHD, (b) myocardial presence of SARS-CoV-2 via RT,-PCR, and (c) levels of ACE2 expression using immunofluorescence staining. RESULTS: Structural heart disease is found in 67 patients, of whom 56 (83.60%) are hospitalized. The myocardium is positive for SARS-CoV-2 in 15 patients (65%) in 23 autopsy cases of lethal COVID-19. Moreover, most hearts with evidence of myocardial SARS-CoV-2 have structural heart disease [11 (91,67%) vs. 1 (8,33%), p = 0.029]. Myocardial presence of SARS-CoV-2 is correlated with a significant downregulation of ACE2 compared to negative control hearts (6.545 ± 1.1818 A.U. vs. 7.764 ± 2.411 A.U., p = 0.003). The clinical course of patients with cardiac SARS-CoV-2 manifestation is unfavorable, resulting in impaired survival (median, 12 days and 4.5 days, respectively, HR 0.30, 95% CI, 0.13 to 0.73, p = 0.0005) CONCLUSIONS: We provide evidence for a correlation between SHD, altered ACE2 receptor expression, and cardiac SARS-CoV-2 manifestation. Consequently, structural heart disease may be considered a distinct risk factor for a severe clinical course after infection with SARS-CoV-2. REGISTRATION NUMBER LOCAL IRB: Ethics Committee of Northwestern and Central Switzerland ID 2020-00629; Ethics Committee of the Medical University Innsbruck EK Nr: 1103/2020. GOV NUMBER: NCT04416100.

SARS-CoV-2, the virus that causes COVID-19, binds to ACE2 receptors to gain entry into cells. The ACE2 receptor is a cell surface protein found in many tissues, including the heart. Studies suggest that people with heart disease are likely to have higher levels of ACE2 receptors, which may explain why they are more susceptible to severe illness from COVID-19. In this study, we identified heart disease as a risk factor for hospitalization in 152 patients who tested positive for SARS-CoV-2. The presence of SARS-CoV-2 in the heart was associated with altered levels of ACE2 receptors and with a shortened survival time in patients. These findings provide evidence for a potential link between heart disease, ACE2 receptor levels, and SARS-CoV-2 infection of the heart, and may help doctors to understand the clinical course of patients with heart disease who contract COVID-19.

One-Year Follow-Up of COVID-19 Patients Indicates Substantial Assay-Dependent Differences in the Kinetics of SARS-CoV-2 Antibodies.

Determination of antibody levels against the nucleocapsid (N) and spike (S) proteins of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are used to estimate the humoral immune response after SARS-CoV-2 infection or vaccination. Differences in the design and specification of antibody assays challenge the interpretation of test results, and comparative studies are often limited to single time points per patient. We determined the longitudinal kinetics of antibody levels of 145 unvaccinated coronavirus disease 2019 (COVID-19) patients at four visits over 1 year upon convalescence using 8 commercial SARS-CoV-2 antibody assays (from Abbott, DiaSorin, Roche, Siemens, and Technoclone), as well as a virus neutralization test (VNT). A linear regression model was used to investigate whether antibody results obtained in the first 6 months after disease onset could predict the VNT results at 12 months. Spike protein-specific antibody tests showed good correlation to the VNT at individual time points (rS, 0.74 to 0.92). While longitudinal assay comparison with the Roche Elecsys anti-SARS-CoV-2 S test showed almost constant antibody concentrations over 12 months, the VNT and all other tests indicated a decline in serum antibody levels (median decrease to 14% to 36% of baseline). The antibody level at 3 months was the best predictor of the VNT results at 12 months after disease onset. The current standardization to a WHO calibrator for normalization to binding antibody units (BAU) is not sufficient for the harmonization of SARS-CoV-2 antibody tests. Assay-specific differences in absolute values and trends over time need to be considered when interpreting the course of antibody levels in patients. IMPORTANCE Determination of antibodies against SARS-CoV-2 will play an important role in detecting a sufficient immune response. Although all the manufacturers expressed antibody levels in binding antibody units per milliliter, thus suggesting comparable results, we found discrepant behavior between the eight investigated assays when we followed the antibody levels in a cohort of 145 convalescent patients over 1 year. While one assay yielded constant antibody levels, the others showed decreasing antibody levels to a varying extent. Therefore, the comparability of the assays must be improved regarding the long-term kinetics of antibody levels. This is a prerequisite for establishing reliable antibody level cutoffs for sufficient individual protection against SARS-CoV-2.