ABSTRACT
Prolonged lung pathology has been associated with COVID-19, yet the cellular and molecular mechanisms behind this chronic inflammatory disease are poorly understood. In this study, we combine advanced imaging and spatial transcriptomics to shed light on the local immune response in severe COVID-19. We show that activated adventitial niches are crucial microenvironments contributing to the orchestration of prolonged lung immunopathology. Up-regulation of the chemokines CCL21 and CCL18 associates to endothelial-to-mesenchymal transition and tissue fibrosis within these niches. CCL21 over-expression additionally links to the local accumulation of T cells expressing the cognate receptor CCR7. These T cells are imprinted with an exhausted phenotype and form lymphoid aggregates that can organize in ectopic lymphoid structures. Our work proposes immune-stromal interaction mechanisms promoting a self-sustained and non-resolving local immune response that extends beyond active viral infection and perpetuates tissue remodeling.
Subject(s)
COVID-19 , Chemokine CCL21 , Chemokines, CC , Humans , COVID-19/immunology , Fibrosis , Lung , T-Lymphocytes/immunologyABSTRACT
BACKGROUND: Acute kidney injury (AKI) occurs frequently in critically ill patients and is associated with adverse outcomes. Cellular mechanisms underlying AKI and kidney cell responses to injury remain incompletely understood. METHODS: We performed single-nuclei transcriptomics, bulk transcriptomics, molecular imaging studies, and conventional histology on kidney tissues from 8 individuals with severe AKI (stage 2 or 3 according to Kidney Disease: Improving Global Outcomes (KDIGO) criteria). Specimens were obtained within 1-2 h after individuals had succumbed to critical illness associated with respiratory infections, with 4 of 8 individuals diagnosed with COVID-19. Control kidney tissues were obtained post-mortem or after nephrectomy from individuals without AKI. RESULTS: High-depth single cell-resolved gene expression data of human kidneys affected by AKI revealed enrichment of novel injury-associated cell states within the major cell types of the tubular epithelium, in particular in proximal tubules, thick ascending limbs, and distal convoluted tubules. Four distinct, hierarchically interconnected injured cell states were distinguishable and characterized by transcriptome patterns associated with oxidative stress, hypoxia, interferon response, and epithelial-to-mesenchymal transition, respectively. Transcriptome differences between individuals with AKI were driven primarily by the cell type-specific abundance of these four injury subtypes rather than by private molecular responses. AKI-associated changes in gene expression between individuals with and without COVID-19 were similar. CONCLUSIONS: The study provides an extensive resource of the cell type-specific transcriptomic responses associated with critical illness-associated AKI in humans, highlighting recurrent disease-associated signatures and inter-individual heterogeneity. Personalized molecular disease assessment in human AKI may foster the development of tailored therapies.
Subject(s)
Acute Kidney Injury , COVID-19 , Acute Kidney Injury/genetics , COVID-19/genetics , Critical Illness , Humans , Kidney , TranscriptomeABSTRACT
OBJECTIVES: To investigate the effect of extracorporeal cytokine reduction by CytoSorb (CytoSorbents, Monmouth Junction, NJ) on COVID-19-associated vasoplegic shock. DESIGN: Prospective, randomized controlled pilot study. SETTING: Eight ICUs at three sites of the tertiary-care university hospital Charité-Universitätsmedizin Berlin. PATIENTS: COVID-19 patients with vasoplegic shock requiring norepinephrine greater than 0.2 µg/kg/min, C-reactive protein greater than 100 mg/L, and indication for hemodialysis. INTERVENTIONS: Randomization of 1:1 to receive CytoSorb for 3-7 days or standard therapy. To account for inadvertent removal of antibiotics, patients in the treatment group received an additional dose at each adsorber change. MEASUREMENTS AND MAIN RESULTS: The primary endpoint was time until resolution of vasoplegic shock, estimated by Cox-regression. Secondary endpoints included mortality, interleukin-6 concentrations, and catecholamine requirements. The study was registered in the German Registry of Clinical Trials (DRKS00021447). From November 2020 to March 2021, 50 patients were enrolled. Twenty-three patients were randomized to receive CytoSorb and 26 patients to receive standard of care. One patient randomized to cytokine adsorption was excluded due to withdrawal of informed consent. Resolution of vasoplegic shock was observed in 13 of 23 patients (56.5%) in the CytoSorb and 12 of 26 patients (46.2%) in the control group after a median of 5 days (interquartile range [IQR], 4-5 d) and 4 days (IQR, 3-5 d). The hazard ratio (HR) for the primary endpoint, adjusted for the predefined variables age, gender, extracorporeal membrane oxygenation-therapy, or time from shock onset to study inclusion was HR, 1.23 (95% CI, 0.54-2.79); p = 0.63. The mortality rate was 78% in the CytoSorb and 73% in the control group (unadjusted HR, 1.17 [95% CI, 0.61-2.23]; p = 0.64). The effects on inflammatory markers, catecholamine requirements, and the type and rates of adverse events were similar between the groups. CONCLUSIONS: In severely ill COVID-19 patients, CytoSorb did not improve resolution of vasoplegic shock or predefined secondary endpoints.
Subject(s)
COVID-19 , Shock , COVID-19/therapy , Cytokines , Humans , Multiple Organ Failure/therapy , Norepinephrine , Pilot Projects , Prospective Studies , Research Design , Treatment OutcomeABSTRACT
INTRODUCTION: Acute kidney injury (AKI) is an important complication in COVID-19, but its precise etiology has not fully been elucidated. Insights into AKI mechanisms may be provided by analyzing the temporal associations of clinical parameters reflecting disease processes and AKI development. METHODS: We performed an observational cohort study of 223 consecutive COVID-19 patients treated at 3 sites of a tertiary care referral center to describe the evolvement of severe AKI (Kidney Disease: Improving Global Outcomes stage 3) and identify conditions promoting its development. Descriptive statistics and explanatory multivariable Cox regression modeling with clinical parameters as time-varying covariates were used to identify risk factors of severe AKI. RESULTS: Severe AKI developed in 70 of 223 patients (31%) with COVID-19, of which 95.7% required kidney replacement therapy. Patients with severe AKI were older, predominantly male, had more comorbidities, and displayed excess mortality. Severe AKI occurred exclusively in intensive care unit patients, and 97.3% of the patients developing severe AKI had respiratory failure. Mechanical ventilation, vasopressor therapy, and inflammatory markers (serum procalcitonin levels and leucocyte count) were independent time-varying risk factors of severe AKI. Increasing inflammatory markers displayed a close temporal association with the development of severe AKI. Sensitivity analysis on risk factors of AKI stage 2 and 3 combined confirmed these findings. CONCLUSION: Severe AKI in COVID-19 was tightly coupled with critical illness and systemic inflammation and was not observed in milder disease courses. These findings suggest that traditional systemic AKI mechanisms rather than kidney-specific processes contribute to severe AKI in COVID-19.
Subject(s)
Acute Kidney Injury/therapy , COVID-19/therapy , Glomerular Filtration Rate , Kidney/physiopathology , Renal Replacement Therapy , Acute Kidney Injury/etiology , Acute Kidney Injury/mortality , Acute Kidney Injury/physiopathology , Aged , COVID-19/complications , COVID-19/mortality , Female , Humans , Male , Recovery of Function , Renal Replacement Therapy/adverse effects , Renal Replacement Therapy/mortality , Retrospective Studies , Time Factors , Treatment OutcomeABSTRACT
Coronavirus disease 2019 (COVID-19) has emerged as a global pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). So far, viral targets of cellular immunity and factors determining successful mounting of T cell responses are poorly defined. We therefore analyzed cellular responses to membrane, nucleocapsid, and spike proteins in individuals suffering from moderate or severe infection and in individuals who recovered from mild disease. We demonstrate that the CoV-2-specific CD4+ T helper cell response is directed against all 3 proteins with comparable magnitude, ex vivo proliferation, and portions of responding patients. However, individuals who died were more likely to have not mounted a cellular response to the proteins. Higher patient age and comorbidity index correlated with increased frequencies of CoV-2-specific CD4+ T cells, harboring higher portions of IL-2-secreting, but lower portions of IFN-γ-secreting, cells. Diminished frequencies of membrane protein-reactive IFN-γ+ T cells were particularly associated with higher acute physiology and chronic health evaluation II scores in patients admitted to intensive care. CoV-2-specific T cells exhibited elevated PD-1 expression in patients with active disease as compared with those individuals who recovered from previous mild disease. In summary, our data suggest a link between individual patient predisposition with respect to age and comorbidity and impairment of CoV-2-specific Th1-type cellular immunity, thereby supporting a concept of altered T cell function in at-risk patients.
Subject(s)
COVID-19/immunology , Interferon-gamma/immunology , Interleukin-2/immunology , Programmed Cell Death 1 Receptor/immunology , SARS-CoV-2/immunology , Th1 Cells/immunology , Adult , Age Factors , Aged , Aged, 80 and over , COVID-19/pathology , Disease Susceptibility , Female , Humans , Male , Middle Aged , Severity of Illness Index , Th1 Cells/pathologyABSTRACT
Acute kidney injury (AKI) is a frequent and severe complication in coronavirus disease 2019 (COVID-19) patients in the intensive care unit. The development of COVID-19 associated AKI is closely linked to the severity of the disease course. The main risk factor for kidney failure requiring kidney replacement therapy is the necessity for invasive ventilation, whereby the onset of renal failure is often closely associated with the timing of intubation. Additionally, the risk factors for a severe course of COVID-19 have been shown to also be risk factors for renal failure. AKI in COVID-19 shows a high mortality and in some patients leads to chronic kidney disease; however, full recovery of kidney function in survivors who need dialysis is not uncommon. With respect to prevention and treatment of renal failure associated with COVID-19, the same recommendations as for AKI from other causes are valid (Kidney Disease: Improving Global Outcomes, KDIGO bundles). Due to the large numbers of patients in the setting of overwhelmed resources, the availability of extracorporeal renal replacement procedures can become critical, especially since hypercoagulation is frequent in COVID19. In order to avoid triage situations, in some centers acute peritoneal dialysis was used as an alternative to extracorporeal procedures.
ABSTRACT
OBJECTIVES: Approximately 8 - 10 % of COVID-19 patients present with a serious clinical course and need for hospitalization, 8% of hospitalized patients need ICU-treatment. Currently, no causal therapy is available and treatment is purely supportive. The main reason for death in critically ill patients is acute respiratory failure. However, in a number of patients a severe hyperinflammatory response with excessively elevated proinflammatory cytokines causes vasoplegic shock resistant to vasopressor therapy. A new polystyrene-based hemoadsorber (CytoSorb®, Cytosorbents Inc., New Jersey, USA) has been shown to adsorb effectively cytokines and other middle molecular weight toxins this way reducing their blood concentrations. This has been routinely used in clinical practice in the EU for other conditions where a cytokine storm occurs and an observational study has just been completed on COVID-19 patients. We hypothesized that the extracorporeal elimination of cytokines in critically ill COVID-19 patients with suspected hyperinflammation and shock may stabilize hemodynamics and improve outcome. The primary endpoint is time until resolution of vasoplegic shock, which is a well implemented, clinically relevant endpoint in critical care studies. TRIAL DESIGN: Phase IIb, multicenter, prospective, open-label, randomized, 1:1 parallel group pilot study comparing the additional use of "CytoSorb" to standard of care without "CytoSorb". PARTICIPANTS: Patients are recruited from the Intensive Care Units (ICUs) of 7 participating centers in Germany (approximately 10 ICUs). All patients aged 18- 80 with positive polymerase chain reaction (PCR) test for SARS-CoV-2, a C-reactive protein (CRP) ≥ 100 mg/l, a Procalcitonin (PCT) < 2 ng/l, and suspected cytokine storm defined via a vasoplegic shock (Norepinephrine > 0.2 µg/min/kg to achieve a Mean Arterial Pressure ≥ 65mmHg). Patients are included irrespective of indication for renal replacement therapy. Suspected or proven bacterial cause for vasoplegic shock is a contraindication. INTERVENTION AND COMPARATOR: Within 24 hours after meeting the inclusion criteria patients will be randomized to receive either standard of care or standard of care and additional "CytoSorb" therapy via a shaldon catheter for 3-7 days. Filter exchange is done every 24 hours. If patients receive antibiotics, an additional dose of antibiotics is administered after each change of "CytoSorb" filter in order to prevent underdosing due to "CytoSorb" treatment. MAIN OUTCOMES: Primary outcome is time to resolution of vasoplegic shock (defined as no need for vasopressors for at least 8 hours in order to sustain a MAP ≥ 65mmHg) in days. Secondary outcomes are 7 day mortality after fulfilling the inclusion criteria, mortality until hospital discharge, Interleukin-6 (IL-6) measurement on day 1 and 3, need for mechanical ventilation, duration of mechanical ventilation, duration of ICU-stay, catecholamine dose on day 1/2/3 after start of "CytoSorb" and acute kidney injury. RANDOMIZATION: An electronic randomization will be performed using the study software secuTrial® administered by the Clinical Study Center (CSC) of the Charité - Universitätsmedizin Berlin, Germany. Randomization is done in blocks by 4 stratified by including center. BLINDING (MASKING): The trial will be non-blinded for the clinicians and patients. The statistician will receive a blinded data set, so that all analyses will be conducted blinded. NUMBERS TO BE RANDOMIZED (SAMPLE SIZE): As this is a pilot study with the goal to examine the feasibility of the study design as well as the intervention effect, no formal sample size calculation was conducted. A total number of approximately 80-100 patients is planned (40-50 patients per group). Safety assessment is done after the inclusion of each 10 patients per randomization group. TRIAL STATUS: Please see the study protocol version from April 24 2020. Recruitment of patients is still pending. TRIAL REGISTRATION: The study was registered on April 27 2020 in the German Registry of Clinical Trials (DRKS) under the number DRKS00021447. FULL PROTOCOL: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.