Growth Differentiation Factor 15 Provides Prognostic Information Superior to Established Cardiovascular and Inflammatory Biomarkers in Unselected Patients Hospitalized With COVID-19.

BACKGROUND: Growth differentiation factor 15 (GDF-15) is a strong prognostic marker in sepsis and cardiovascular disease (CVD). The prognostic value of GDF-15 in coronavirus disease 2019 (COVID-19) is unknown. METHODS: Consecutive, hospitalized patients with laboratory-confirmed infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and symptoms of COVID-19 were enrolled in the prospective, observational COVID Mechanisms Study. Biobank samples were collected at baseline, day 3 and day 9. The primary end point was admission to the intensive care unit or death during hospitalization, and the prognostic performance of baseline and serial GDF-15 concentrations were compared with that of established infectious disease and cardiovascular biomarkers. RESULTS: Of the 123 patients enrolled, 35 (28%) reached the primary end point; these patients were older, more often had diabetes, and had lower oxygen saturations and higher National Early Warning Scores on baseline. Baseline GDF-15 concentrations were elevated (>95th percentile in age-stratified healthy individuals) in 97 (79%), and higher concentrations were associated with detectable SARS-CoV-2 viremia and hypoxemia (both P<0.001). Patients reaching the primary end point had higher concentrations of GDF-15 (median, 4225 [IQR, 3197-5972] pg/mL versus median, 2187 [IQR, 1344-3620] pg/mL, P<0.001). The area under the receiver operating curve was 0.78 (95% CI, 0.70-0.86). The association between GDF-15 and the primary end point persisted after adjusting for age, sex, race, body mass index, estimated glomerular filtration rate, previous myocardial infarction, heart failure, and atrial fibrillation (P<0.001) and was superior and incremental to interleukin-6, C-reactive protein, procalcitonin, ferritin, D-dimer, cardiac troponin T, and N-terminal pro-B-type natriuretic peptide. Increase in GDF-15 from baseline to day 3 was also greater in patients reaching the primary end point (median, 1208 [IQR, 0-4305] pg/mL versus median, -86 [IQR, -322 to 491] pg/mL, P<0.001). CONCLUSIONS: GDF-15 is elevated in the majority of patients hospitalized with COVID-19, and higher concentrations are associated with SARS-CoV-2 viremia, hypoxemia, and worse outcome. The prognostic value of GDF-15 was additional and superior to established cardiovascular and inflammatory biomarkers. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04314232.

Severe Acute Respiratory Syndrome Coronavirus 2 RNA in Plasma Is Associated With Intensive Care Unit Admission and Mortality in Patients Hospitalized With Coronavirus Disease 2019.

The clinical significance of severe acute respiratory syndrome coronavirus 2 RNA in the circulation is unknown. In this prospective cohort study, we detected viral RNA in the plasma of 58 of 123 (47%) patients hospitalized with coronavirus disease 2019. RNA was detected more frequently, and levels were higher, in patients who were admitted to the intensive care unit and/or died.

Cardiac pathology 6 months after hospitalization for COVID-19 and association with the acute disease severity.

BACKGROUND: Coronavirus disease 2019 (COVID-19) may cause myocardial injury and myocarditis, and reports of persistent cardiac pathology after COVID-19 have raised concerns of long-term cardiac consequences. We aimed to assess the presence of abnormal cardiovascular resonance imaging (CMR) findings in patients recovered from moderate-to-severe COVID-19, and its association with markers of disease severity in the acute phase. METHODS: Fifty-eight (49%) survivors from the prospective COVID MECH study, underwent CMR median 175 [IQR 105-217] days after COVID-19 hospitalization. Abnormal CMR was defined as left ventricular ejection fraction (LVEF) <50% or myocardial scar by late gadolinium enhancement. CMR indices were compared to healthy controls (n = 32), and to circulating biomarkers measured during the index hospitalization. RESULTS: Abnormal CMR was present in 12 (21%) patients, of whom 3 were classified with major pathology (scar and LVEF <50% or LVEF <40%). There was no difference in the need of mechanical ventilation, length of hospital stay, and vital signs between patients with vs without abnormal CMR after 6 months. Severe acute respiratory syndrome coronavirus 2 viremia and concentrations of inflammatory biomarkers during the index hospitalization were not associated with persistent CMR pathology. Cardiac troponin T and N-terminal pro-B-type natriuretic peptide concentrations on admission, were higher in patients with CMR pathology, but these associations were not significant after adjusting for demographics and established cardiovascular disease. CONCLUSIONS: CMR pathology 6 months after moderate-to-severe COVID-19 was present in 21% of patients and did not correlate with severity of the disease. Cardiovascular biomarkers during COVID-19 were higher in patients with CMR pathology, but with no significant association after adjusting for confounders. TRIAL REGISTRATION: COVID MECH Study ClinicalTrials.gov Identifier: NCT04314232.

A single-centre, prospective cohort study of COVID-19 patients admitted to ICU for mechanical ventilatory support.

BACKGROUND: Mortality rates in COVID-19 patients in need of mechanical ventilation are high, with wide variations between countries. Most studies were retrospective, and results may not be generalizable due to differences in demographics, healthcare organization and surge capacity. We present a cohort of mechanically ventilated COVID-19 patients from a resource-rich, publicly financed healthcare system. METHODS: Prospective study from a tertiary hospital. Consecutive SARS-CoV-2 positive adult patients admitted to the ICU for mechanical ventilation from 10 March 2020 to 04 May 2020 were included. Triage and treatment were protocolized. High-dose dalteparin was adjusted by D-dimer. Demographics, treatments and high-resolution physiological variables were collected. Outcomes were 30-day and hospital mortality. Data are medians (quartiles). RESULTS: Of the 1484 persons in the hospital catchment area testing positive for SARS-CoV-2, 201 (13.5%) were hospitalized. Thirty-eight (19%) patients were mechanically ventilated, of whom five (13%) died. Of the 163 patients treated with supplemental oxygen, eight (5%) died. In ventilated patients (75% males, age 61 (53-70) years), severe, moderate and mild ARDS was present in 25%, 70% and 5%. Tidal volume ≤8 mL/kg ideal bodyweight was achieved in 34 (94%) patients. Proning and neuromuscular blockers were used in 19 (54%) and 20 (61%) patients. Duration of ventilation was 12 days (8-23). D-dimer peaked at 3.8 mg/L (2.1-5.3), and maximum dalteparin dose was 15 000 IU/24 h (10 000-15 000). Despite organizational changes, a high degree of adherence to treatment protocols was achieved. CONCLUSION: In a prospective cohort study of mechanically ventilated COVID-19 patients treated in a resource-rich, publicly financed healthcare system, mortality was considerably lower than previously reported in retrospective studies.

Longitudinal whole blood transcriptomic analysis characterizes neutrophil activation and interferon signaling in moderate and severe COVID-19.

A maladaptive inflammatory response has been implicated in the pathogenesis of severe COVID-19. This study aimed to characterize the temporal dynamics of this response and investigate whether severe disease is associated with distinct gene expression patterns. We performed microarray analysis of serial whole blood RNA samples from 17 patients with severe COVID-19, 15 patients with moderate disease and 11 healthy controls. All study subjects were unvaccinated. We assessed whole blood gene expression patterns by differential gene expression analysis, gene set enrichment, two clustering methods and estimated relative leukocyte abundance using CIBERSORT. Neutrophils, platelets, cytokine signaling, and the coagulation system were activated in COVID-19, and this broad immune activation was more pronounced in severe vs. moderate disease. We observed two different trajectories of neutrophil-associated genes, indicating the emergence of a more immature neutrophil phenotype over time. Interferon-associated genes were strongly enriched in early COVID-19 before falling markedly, with modest severity-associated differences in trajectory. In conclusion, COVID-19 necessitating hospitalization is associated with a broad inflammatory response, which is more pronounced in severe disease. Our data suggest a progressively more immature circulating neutrophil phenotype over time. Interferon signaling is enriched in COVID-19 but does not seem to drive severe disease.

Mortality and Sequential Organ Failure Assessment Score in Patients With Suspected Sepsis: The Impact of Acute and Preexisting Organ Failures and Infection Likelihood.

The Sequential Organ Failure Assessment (SOFA) was chosen in the definition of sepsis due to superior validity in predicting mortality. However, few studies have assessed the contributions of acute versus chronic organ failures to SOFA for mortality prediction. OBJECTIVES: The main objective in this study was to assess the relative importance of chronic and acute organ failures in mortality prediction in patients with suspected sepsis at hospital admission. We also evaluated how the presence of infection influenced the ability of SOFA to predict 30-day mortality. DESIGN SETTING AND PARTICIPANTS: Single-center prospective cohort study including 1,313 adult patients with suspected sepsis in rapid response teams in the emergency department. MAIN OUTCOMES AND MEASURES: The main outcome was 30-day mortality. We measured the maximum total SOFA score during admission (SOFATotal), whereas preexisting chronic organ failure SOFA (SOFAChronic) score was assessed by chart review, allowing calculation of the corresponding acute SOFA (SOFAAcute) score. Likelihood of infection was determined post hoc as "No infection" or "Infection." RESULTS: SOFAAcute and SOFAChronic were both associated with 30-day mortality, adjusted for age and sex (adjusted odds ratios [AORs], 1.3; 95% CI, 1.3-14 and 1.3; 1.2-1.7), respectively. Presence of infection was associated with lower 30-day mortality (AOR, 0.4; 95% CI, 0.2-0.6), even when corrected for SOFA. In "No infection" patients, SOFAAcute was not associated with mortality (AOR, 1.1; 95% CI, 1.0-1.2), and in this subgroup, neither SOFAAcute greater than or equal to 2 (relative risk [RR], 1.1; 95% CI, 0.6-1.8) nor SOFATotal greater than or equal to 2 (RR, 3.6; 95% CI, 0.9-14.1) was associated with higher mortality. CONCLUSIONS AND RELEVANCE: Chronic and acute organ failures were equally associated with 30-day mortality in suspected sepsis. A substantial part of the total SOFA score was due to chronic organ failure, calling for caution when using total SOFA in defining sepsis and as an outcome in intervention studies. SOFA's mortality prediction ability was highly dependent on actual presence of infection.

TiSA: TimeSeriesAnalysis-a pipeline for the analysis of longitudinal transcriptomics data.

Improved transcriptomic sequencing technologies now make it possible to perform longitudinal experiments, thus generating a large amount of data. Currently, there are no dedicated or comprehensive methods for the analysis of these experiments. In this article, we describe our TimeSeries Analysis pipeline (TiSA) which combines differential gene expression, clustering based on recursive thresholding, and a functional enrichment analysis. Differential gene expression is performed for both the temporal and conditional axes. Clustering is performed on the identified differentially expressed genes, with each cluster being evaluated using a functional enrichment analysis. We show that TiSA can be used to analyse longitudinal transcriptomic data from both microarrays and RNA-seq, as well as small, large, and/or datasets with missing data points. The tested datasets ranged in complexity, some originating from cell lines while another was from a longitudinal experiment of severity in COVID-19 patients. We have also included custom figures to aid with the biological interpretation of the data, these plots include Principal Component Analyses, Multi Dimensional Scaling plots, functional enrichment dotplots, trajectory plots, and complex heatmaps showing the broad overview of results. To date, TiSA is the first pipeline to provide an easy solution to the analysis of longitudinal transcriptomics experiments.

SARS-CoV-2 Viremia is Associated With Inflammatory, But Not Cardiovascular Biomarkers, in Patients Hospitalized for COVID-19.

Background COVID-19 may present with a variety of cardiovascular manifestations, and elevations of biomarkers reflecting myocardial injury and stress are prevalent. SARS-CoV-2 has been found in cardiac tissue, and myocardial dysfunction post-COVID-19 may occur. However, the association between SARS-CoV-2 RNA in plasma and cardiovascular biomarkers remains unknown. Methods and Results COVID MECH (COVID-19 Mechanisms) was a prospective, observational study enrolling consecutive, hospitalized patients with laboratory-confirmed infection with SARS-CoV-2 and symptoms of COVID-19. Biobank plasma samples used to measure SARS-CoV-2 RNA and cardiovascular and inflammatory biomarkers were collected in 123 patients at baseline, and in 96 patients (78%) at day 3. Patients were aged 60±15 (mean ± SD) years, 71 (58%) were men, 68 (55%) were White, and 31 (25%) received mechanical ventilation during hospitalization. SARS-CoV-2 RNA was detected in plasma from 48 (39%) patients at baseline. Patients with viremia were more frequently men, had more diabetes mellitus, and lower oxygen saturation. Patients with viremia had higher concentrations of interleukin-6, C-reactive protein, procalcitonin, and ferritin (all <0.001), but comparable levels of cTnT (cardiac troponin T; P=0.09), NT-proBNP (N-terminal pro-B-type natriuretic peptide; P=0.27) and D-dimer (P=0.67) to patients without viremia. SARS-CoV-2 RNA was present in plasma at either baseline or day 3 in 50 (52%) patients, and these patients experienced increase from baseline to day 3 in NT-proBNP and D-dimer concentrations, while there was no change in cTnT. Conclusions SARS-CoV-2 viremia was associated with increased concentrations of inflammatory, but not cardiovascular biomarkers. NT-proBNP and D-dimer, but not cTnT, increased from baseline to day 3 in patients with viremia. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT04314232.

Soluble ST2 concentrations associate with in-hospital mortality and need for mechanical ventilation in unselected patients with COVID-19.

OBJECTIVE: Soluble ST2 (sST2) reflects inflammation, endothelial dysfunction and myocardial fibrosis, is produced in the lungs and is an established biomarker in heart failure. We sought to determine the role of sST2 in COVID-19 by assessing pathophysiological correlates and its association to in-hospital outcomes. METHODS: We enrolled 123 consecutive, hospitalised patients with COVID-19 in the prospective, observational COVID-19 MECH study. Biobank samples were collected at baseline, day 3 and day 9. The key exposure variable was sST2, and the outcome was ICU treatment with mechanical ventilation or in-hospital death. RESULTS: Concentrations of sST2 at baseline was median 48 (IQR 37-67) ng/mL, and 74% had elevated concentrations (>37.9 ng/mL). Higher baseline sST2 concentrations were associated with older age, male sex, white race, smoking, diabetes, hypertension and chronic kidney disease. Baseline sST2 also associated with the presence of SARS-CoV-2 viraemia, lower oxygen saturation, higher respiratory rate and increasing concentrations of biomarkers reflecting inflammation, thrombosis and cardiovascular disease. During the hospitalisation, 8 (7%) patients died and 27 (22%) survivors received intensive care unit (ICU) treatment. Baseline sST2 concentrations demonstrated a graded association with disease severity (median, IQR): medical ward 43 (36-59) ng/mL; ICU 67 (39-104) ng/mL and non-survivors 107 (72-116) ng/mL (p<0.001 for all comparisons). These associations persisted at day 3 and day 9 . CONCLUSIONS: sST2 concentrations associate with SARS-CoV-2 viraemia, hypoxaemia and concentrations of inflammatory and cardiovascular biomarkers. There was a robust association between baseline sST2 and disease severity that was independent of, and superior to, established risk factors. sST2 reflects key pathophysiology and may be a promising biomarker in COVID-19. TRIAL REGISTRATION NUMBER: NCT04314232.

Immune activation and HIV-specific T cell responses are modulated by a cyclooxygenase-2 inhibitor in untreated HIV-infected individuals: An exploratory clinical trial.

Pathologically elevated immune activation and inflammation contribute to HIV disease progression and immunodeficiency, potentially mediated by elevated levels of prostaglandin E2, which suppress HIV-specific T cell responses. We have previously shown that a high dose of the cyclooxygenase-2 inhibitor celecoxib can reduce HIV-associated immune activation and improve IgG responses to T cell-dependent vaccines. In this follow-up study, we included 56 HIV-infected adults, 28 antiretroviral therapy (ART)-naïve and 28 on ART with undetectable plasma viremia but CD4 counts below 500 cells/µL. Patients in each of the two study groups were randomized to receive 90 mg qd of the cyclooxygenase-2 inhibitor etoricoxib for six months, two weeks or to a control arm, respectively. T cell activation status, HIV Gag-specific T cell responses and plasma inflammatory markers, tryptophan metabolism and thrombin generation were analyzed at baseline and after four months. In addition, patients received tetanus toxoid, conjugated pneumococcal and seasonal influenza vaccines, to which IgG responses were determined after four weeks. In ART-naïve patients, etoricoxib reduced the density of the activation marker CD38 in multiple CD8+ T cell subsets, improved Gag-specific T cell responses, and reduced in vitro plasma thrombin generation, while no effects were seen on plasma markers of inflammation or tryptophan metabolism. No significant immunological effects of etoricoxib were observed in ART-treated patients. Patients receiving long-term etoricoxib treatment had poorer tetanus toxoid and conjugated pneumococcal vaccine responses than those receiving short-course etoricoxib. Cyclooxygenase-2 inhibitors may attenuate harmful immune activation in HIV-infected patients without access to ART.

Regulation of Gag- and Env-Specific CD8+ T Cell Responses in ART-Naïve HIV-Infected Patients: Potential Implications for Individualized Immunotherapy.

Strategies to develop a functional cure for HIV infection will likely require boosting of effector T cell responses to eliminate reactivated, latently infected cells. We have recently explored an assay for assessing antigen-specific regulation of T cell proliferation, which was related to clinical progression in untreated patients and to vaccine efficacy in two trials of therapeutic Gag-based vaccines. We here expand the same assay to further investigate regulation mediated by various inhibitory pathways. Peripheral blood mononuclear cells from 26 asymptomatic HIV-infected, antiretroviral therapy-naïve patients were stimulated with Gag and Env overlapping peptide panels for 5 days. Monoclonal antibodies (mAbs) blocking inhibitory mediators interleukin (IL) 10, transforming growth factor (TGF) ß, programmed death ligand (PD-L) 1 and herpes virus entry mediator (HVEM) were added to parallel cultures. Functional T cell regulation (FTR) was defined as the difference in proliferation between stimulated cultures with and without blocking mAbs. FTR was detected in 54% of patients. Blockade of IL-10/PD-L1 and IL10/TGF-ß detected all cases with Gag- and Env-associated FTR, respectively. In accordance with previous findings, isolated Env FTR was associated with higher plasma HIV RNA and lower CD4 counts, while patients with both Gag and Env FTR also had higher Gag- and Env-specific proliferative CD8+ T cell responses. There was no association between FTR and frequencies of activated regulatory T cells. In conclusion, we observed substantial heterogeneity in FTR between patients, inhibitory pathways and HIV antigens. FTR may help to individualize immunomodulation and warrants further assessment in clinical immunotherapy trials.

High MIP-1ß Levels in Plasma Predict Long-Term Immunological Nonresponse to Suppressive Antiretroviral Therapy in HIV Infection.

BACKGROUND: HIV-infected patients who fail to reconstitute their CD4 T-cell counts during suppressive antiretroviral therapy (ART) have increased risk of both AIDS-related and non-AIDS-related morbidity and mortality. Improved understanding of immunological nonresponse (INR) is necessary to enable earlier clinical intervention. METHODS: In a cohort of 112 HIV-infected patients starting ART, we performed a serial analysis of 32 plasma-soluble markers, assessed by multiplex cytokine and enzyme immunoassay. Samples were drawn pre-ART and during the first 3 years of treatment, with a final observation time of 8.4 years (interquartile range, 7.0-10.7 years) on ART. Long-term INR (LT-INR) was defined as failure to reach a CD4 T-cell count >350 cells per microliter. Marker stability was evaluated by parallel analysis of samples from ART-naïve and HIV-seronegative controls. RESULTS: Baseline CD4 T-cell counts predicted subsequent LT-INR (n = 15) [odds ratio, 1.10 (95% confidence interval: 1.01 to 1.19) pr. 10 cells/µL reduction in CD4 count, P = 0.030] in the cohort as a whole, but not in patients with baseline CD4 counts <200 cells per microliter (n = 78). LT-INR was best characterized by elevated plasma levels of the CC chemokine macrophage inflammatory protein 1ß (MIP-1ß), both at baseline (pre-ART) and during ART. In patients with baseline CD4 counts <200 cells per microliter, baseline MIP-1ß predicted LT-INR [odds ratio 1.23 (95% confidence interval: 1.02 to 1.47) per 10 pg/mL increase in MIP-1ß, P = 0.029]. CONCLUSIONS: Elevated pre-ART levels of MIP-1ß identified LT-INR patients who started ART at CD4 counts <200. INR was characterized by persistently high MIP-1ß during suppressive ART. Thus, MIP-1ß may be of use for early identification of LT-INR.