Managing Catecholamine Release Syndrome During and Following Lu-177-DOTATATE in High-Risk Pheochromocytoma Patients

Pheochromocytomas and paragangliomas (PPGLs) are rare catecholamine-producing tumors that express somatostatin receptors (SSTR) that can be treated with lutetium-177 DOTATATE (Lu-177-TRT); however, treatment can be associated with life-threatening cardiovascular events. A patient case with management strategies for high-risk PPGL patients receiving Lu-177-TRT is described. The 78-year-old patient with metastatic paraganglioma was enrolled and treated under NCT03206060. Deemed to be at high risk, the patient was preemptively admitted to the intensive care unit (ICU) with central line access placed. Due to comorbidities, a reduced dose of 100 mCi x 4 cycles was used for this patient. Vital signs, blood work, and serum catecholamine levels were obtained at various time points. Despite reduced dosing, the patient still developed a severe hypertensive reaction with systolic blood pressure of 240 mmHg within minutes of Lu-177-TRT infusion, which was controlled with an intravenous nicardipine drip. The patient remained in the ICU for 24 hours post Lu-177-TRT before moving to an inpatient ward for an additional 24 hours. All subsequent infusions were performed using reduced doses with elective ICU admissions and were well-tolerated. Despite the increased risk, metastatic PPGL patients can be safely treated with proper staff training, monitoring, and preparation for intravenous medications, especially nicardipine.

Ebola Virus Tropism in Ex Vivo Cynomolgus Macaque Ocular Tissues

Ocular complications of Ebola virus disease are well-documented and long-term sequelae in survivors are common and lead to considerable morbidity. However, little is currently known regarding EBOV's tropism and replication kinetics within the eye. To date, limited studies have utilized in vitro infections of ocular cell lines and analyses of archived pathology samples to investigate these issues. Here, we employed ex vivo cultures of cynomolgus macaque eyes to determine the tropism of EBOV in 7 different ocular tissues: cornea, anterior sclera with bulbar conjunctiva, ciliary body, iris, lens, neural retina, and retina pigment epithelium. We report that, except for neural retina, all tissues supported EBOV replication. Retina pigment epithelium produced the fastest growth and highest viral RNA loads, although the differences were not statistically significant. Immunohistochemical staining confirmed and further characterized infection. This study demonstrates that EBOV has a broad tropism within the eye.

A Single Case Observation: Is the Ebola Virus Soluble Glycoprotein an Indicator of Viral Recrudescence?

This case study investigated the long-term expression dynamics of Ebola virus (EBOV) soluble glycoprotein (sGP) in the serum of a patient who was infected with EBOV in West Africa and recovered from acute Ebola virus disease (EVD) at the National Institutes of Health Clinical Center in Bethesda, Maryland. Samples from this patient were collected during acute EVD and during convalescence up to day 361 following illness onset. Although blood samples were negative by reverse transcription-quantitative polymerase chain reaction after recovery from acute EVD, we detected small amounts of EBOV sGP in the serum of the patient long after recovery, potentially indicating viral recrudescence. As this was only observed in a single patient, additional longitudinal patient samples are needed to confirm our hypothesis that EBOV sGP may be an indicator of viral recrudescence long after recovery from acute EVD.

Clinical and Immunologic Correlates of Vasodilatory Shock Among Ebola Virus-Infected Nonhuman Primates in a Critical Care Model

BACKGROUND

Existing models of Ebola virus infection have not fully characterized the pathophysiology of shock in connection with daily virologic, clinical, and immunologic parameters. We implemented a nonhuman primate critical care model to investigate these associations.

METHODS

Two rhesus macaques received a target dose of 1000 plaque-forming units of Ebola virus intramuscularly with supportive care initiated on day 3. High-dimensional spectral cytometry was used to phenotype neutrophils and peripheral blood mononuclear cells daily.

RESULTS

We observed progressive vasodilatory shock with preserved cardiac function following viremia onset on day 5. Multiorgan dysfunction began on day 6 coincident with the nadir of circulating neutrophils. Consumptive coagulopathy and anemia occurred on days 7 to 8 along with irreversible shock, followed by death. The monocyte repertoire began shifting on day 4 with a decline in classical and expansion of double-negative monocytes. A selective loss of CXCR3-positive B and T cells, expansion of naive B cells, and activation of natural killer cells followed viremia onset.

CONCLUSIONS

Our model allows for high-fidelity characterization of the pathophysiology of acute Ebola virus infection with host innate and adaptive immune responses, which may advance host-targeted therapy design and evaluation for use after the onset of multiorgan failure.

Histopathology and SARS-CoV-2 Cellular Localization in Eye Tissues of COVID-19 Autopsies

Ophthalmic manifestations and tissue tropism of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been reported in association with coronavirus disease 2019 (COVID-19), but the pathology and cellular localization of SARS-CoV-2 are not well characterized. The objective of this study was to evaluate macroscopic and microscopic changes and investigate cellular localization of SARS-CoV-2 across ocular tissues at autopsy. Ocular tissues were obtained from 25 patients with COVID-19 at autopsy. SARS-CoV-2 nucleocapsid gene RNA was previously quantified by droplet digital PCR from one eye. Herein, contralateral eyes from 21 patients were fixed in formalin and subject to histopathologic examination. Sections of the droplet digital PCR-positive eyes from four other patients were evaluated by in situ hybridization to determine the cellular localization of SARS-CoV-2 spike gene RNA. Histopathologic abnormalities, including cytoid bodies, vascular changes, and retinal edema, with minimal or no inflammation in ocular tissues were observed in all 21 cases evaluated. In situ hybridization localized SARS-CoV-2 RNA to neuronal cells of the retinal inner and outer layers, ganglion cells, corneal epithelia, scleral fibroblasts, and oligodendrocytes of the optic nerve. In conclusion, a range of common histopathologic alterations were identified within ocular tissue, and SARS-CoV-2 RNA was localized to multiple cell types. Further studies will be required to determine whether the alterations observed were caused by SARS-CoV-2 infection, the host immune response, and/or preexisting comorbidities.

SARS-CoV-2 reservoir in post-acute sequelae of COVID-19 (PASC)

Millions of people are suffering from Long COVID or post-acute sequelae of COVID-19 (PASC). Several biological factors have emerged as potential drivers of PASC pathology. Some individuals with PASC may not fully clear the coronavirus SARS-CoV-2 after acute infection. Instead, replicating virus and/or viral RNA-potentially capable of being translated to produce viral proteins-persist in tissue as a 'reservoir'. This reservoir could modulate host immune responses or release viral proteins into the circulation. Here we review studies that have identified SARS-CoV-2 RNA/protein or immune responses indicative of a SARS-CoV-2 reservoir in PASC samples. Mechanisms by which a SARS-CoV-2 reservoir may contribute to PASC pathology, including coagulation, microbiome and neuroimmune abnormalities, are delineated. We identify research priorities to guide the further study of a SARS-CoV-2 reservoir in PASC, with the goal that clinical trials of antivirals or other therapeutics with potential to clear a SARS-CoV-2 reservoir are accelerated.

Ebola virus shed glycoprotein is toxic to human T, B, and natural killer lymphocytes

Lymphocyte depletion is a distinctive feature of Ebola virus (EBOV) disease. The ectodomain of EBOV glycoprotein (GP) is cleaved off the surface of infected cells into circulation as shed GP. To test the hypothesis that shed GP induces lymphocyte death, we cultured primary human B, NK, or T cells with shed GP in vitro. We found that shed GP dependably decreased B, NK, and T cell viability across donors. B and NK cells exhibited higher susceptibility than T cells. Continuous monitoring revealed shed GP began to kill B and NK cells by 4 h and T cells by 5 h. We also demonstrated that shed GP-induced lymphocyte death can be both caspase dependent and caspase independent. Our data are evidence that the cytotoxic effect of shed GP on lymphocytes may contribute to EBOV disease and highlight the need for further research to clarify mechanisms of shed GP-induced death.

Pulmonary Co-Infections Detected Premortem Underestimate Postmortem Findings in a COVID-19 Autopsy Case Series

Bacterial and fungal co-infections are reported complications of coronavirus disease 2019 (COVID-19) in critically ill patients but may go unrecognized premortem due to diagnostic limitations. We compared the premortem with the postmortem detection of pulmonary co-infections in 55 fatal COVID-19 cases from March 2020 to March 2021. The concordance in the premortem versus the postmortem diagnoses and the pathogen identification were evaluated. Premortem pulmonary co-infections were extracted from medical charts while applying standard diagnostic definitions. Postmortem co-infection was defined by compatible lung histopathology with or without the detection of an organism in tissue by bacterial or fungal staining, or polymerase chain reaction (PCR) with broad-range bacterial and fungal primers. Pulmonary co-infection was detected premortem in significantly fewer cases (15/55, 27%) than were detected postmortem (36/55, 65%; p < 0.0001). Among cases in which co-infection was detected postmortem by histopathology, an organism was identified in 27/36 (75%) of cases. Pseudomonas, Enterobacterales, and Staphylococcus aureus were the most frequently identified bacteria both premortem and postmortem. Invasive pulmonary fungal infection was detected in five cases postmortem, but in no cases premortem. According to the univariate analyses, the patients with undiagnosed pulmonary co-infection had significantly shorter hospital (p = 0.0012) and intensive care unit (p = 0.0006) stays and significantly fewer extra-pulmonary infections (p = 0.0021). Bacterial and fungal pulmonary co-infection are under-recognized complications in critically ill patients with COVID-19.

Maternal transfer of IgA and IgG SARS-CoV-2 specific antibodies transplacentally and via breast milk feeding

BACKGROUND

Although there have been many studies on antibody responses to SARS-CoV-2 in breast milk, very few have looked at the fate of these in the infant, and whether they are delivered to immunologically relevant sites in infants.

METHODS

Mother/infant pairs (mothers who breast milk fed and who were SARS-CoV-2 vaccinated before or after delivery) were recruited for this cross-sectional study. Mother blood, mother breast milk, infant blood, infant nasal specimen, and infant stool was tested for IgA and IgG antibodies against SARS-CoV-2 spike trimer.

RESULTS

Thirty-one mother/infant pairs were recruited. Breast milk fed infants acquired systemic anti-spike IgG antibodies only if their mothers were vaccinated antepartum (100% Antepartum; 0% Postpartum; P<0.0001). Breast milk fed infants acquired mucosal anti-spike IgG antibodies (in the nose) only if their mothers were vaccinated antepartum (89% Antepartum; 0% Postpartum; P<0.0001). None of the infants in either group had anti-spike IgA in the blood. Surprisingly, 33% of the infants whose mothers were vaccinated antepartum had high titer anti-spike IgA in the nose (33% Antepartum; 0% Postpartum; P = 0.03). Half-life of maternally transferred plasma IgG antibodies in the Antepartum infant cohort was ~70 days.

CONCLUSION

Vaccination antepartum followed by breast milk feeding appears to be the best way to provide systemic and local anti-SARS-CoV-2 antibodies for infants. The presence of high titer SARS-CoV-2-specific IgA in the nose of infants points to the potential importance of breast milk feeding early in life for maternal transfer of mucosal IgA antibodies. Expectant mothers should consider becoming vaccinated antepartum and consider breast milk feeding for optimal transfer of systemic and mucosal antibodies to their infants.

Semi-parametric modeling of SARS-CoV-2 transmission using tests, cases, deaths, and seroprevalence data

Mechanistic models fit to streaming surveillance data are critical to understanding the transmission dynamics of an outbreak as it unfolds in real-time. However, transmission model parameter estimation can be imprecise, and sometimes even impossible, because surveillance data are noisy and not informative about all aspects of the mechanistic model. To partially overcome this obstacle, Bayesian models have been proposed to integrate multiple surveillance data streams. We devised a modeling framework for integrating SARS-CoV-2 diagnostics test and mortality time series data, as well as seroprevalence data from cross-sectional studies, and tested the importance of individual data streams for both inference and forecasting. Importantly, our model for incidence data accounts for changes in the total number of tests performed. We model the transmission rate, infection-to-fatality ratio, and a parameter controlling a functional relationship between the true case incidence and the fraction of positive tests as time-varying quantities and estimate changes of these parameters nonparametrically. We compare our base model against modified versions which do not use diagnostics test counts or seroprevalence data to demonstrate the utility of including these often unused data streams. We apply our Bayesian data integration method to COVID-19 surveillance data collected in Orange County, California between March 2020 and February 2021 and find that 32-72% of the Orange County residents experienced SARS-CoV-2 infection by mid-January, 2021. Despite this high number of infections, our results suggest that the abrupt end of the winter surge in January 2021 was due to both behavioral changes and a high level of accumulated natural immunity.

Spleen tyrosine kinase inhibition restores myeloid homeostasis in COVID-19

Spleen tyrosine kinase (SYK) is a previously unidentified therapeutic target that inhibits neutrophil and macrophage activation in coronavirus disease 2019 (COVID-19). Fostamatinib, a SYK inhibitor, was studied in a phase 2 placebo-controlled randomized clinical trial and was associated with improvements in many secondary end points related to efficacy. Here, we used a multiomic approach to evaluate cellular and soluble immune mediator responses of patients enrolled in this trial. We demonstrated that SYK inhibition was associated with reduced neutrophil activation, increased circulation of mature neutrophils (CD10⁺CD33^-), and decreased circulation of low-density granulocytes and polymorphonuclear myeloid-derived suppressor cells (HLA-DR^-CD33⁺CD11b^-). SYK inhibition was also associated with normalization of transcriptional activity in circulating monocytes relative to healthy controls, an increase in frequency of circulating nonclassical and HLA-DR^hi classical monocyte populations, and restoration of interferon responses. Together, these data suggest that SYK inhibition may mitigate proinflammatory myeloid cellular and soluble mediator responses thought to contribute to immunopathogenesis of severe COVID-19.

Successful lung transplantation using an allograft from a COVID-19-recovered donor: a potential role for subgenomic RNA to guide organ utilization

Although the risk of SARS-CoV-2 transmission through lung transplantation from acutely infected donors is high, the risks of virus transmission and long-term lung allograft outcomes are not as well described when using pulmonary organs from COVID-19-recovered donors. We describe successful lung transplantation for a COVID-19-related lung injury using lungs from a COVID-19-recovered donor who was retrospectively found to have detectable genomic SARS-CoV-2 RNA in the lung tissue by multiple highly sensitive assays. However, SARS-CoV-2 subgenomic RNA (sgRNA), a marker of viral replication, was not detectable in the donor respiratory tissues. One year after lung transplantation, the recipient has a good functional status, walking 1 mile several times per week without the need for supplemental oxygen and without any evidence of donor-derived SARS-CoV-2 transmission. Our findings highlight the limitations of current clinical laboratory diagnostic assays in detecting the persistence of SARS-CoV-2 RNA in the lung tissue. The persistence of SARS-CoV-2 RNA in the donor tissue did not appear to represent active viral replication via sgRNA testing and, most importantly, did not negatively impact the allograft outcome in the first year after lung transplantation. sgRNA is easily performed and may be a useful assay for assessing viral infectivity in organs from donors with a recent infection.

Development, refinement, and characterization of a nonhuman primate critical care environment

BACKGROUND

Systemic inflammatory response remains a poorly understood cause of morbidity and mortality after traumatic injury. Recent nonhuman primate (NHP) trauma models have been used to characterize the systemic response to trauma, but none have incorporated a critical care phase without the use of general anesthesia. We describe the development of a prolonged critical care environment with sedation and ventilation support, and also report corresponding NHP biologic and inflammatory markers.

METHODS

Eight adult male rhesus macaques underwent ventilation with sedation for 48-96 hours in a critical care setting. Three of these NHPs underwent "sham" procedures as part of trauma control model development. Blood counts, chemistries, coagulation studies, and cytokines/chemokines were collected throughout the study, and histopathologic analysis was conducted at necropsy.

RESULTS

Eight NHPs were intentionally survived and extubated. Three NHPs were euthanized at 72-96 hours without extubation. Transaminitis occurred over the duration of ventilation, but renal function, acid-base status, and hematologic profile remained stable. Chemokine and cytokine analysis were notable for baseline fold-change for Il-6 and Il-1ra (9.7 and 42.7, respectively) that subsequently downtrended throughout the experiment unless clinical respiratory compromise was observed.

CONCLUSIONS

A NHP critical care environment with ventilation support is feasible but requires robust resources. The inflammatory profile of NHPs is not profoundly altered by sedation and mechanical ventilation. NHPs are susceptible to the pulmonary effects of short-term ventilation and demonstrate a similar bioprofile response to ventilator-induced pulmonary pathology. This work has implications for further development of a prolonged care NHP model.

Adaptive immune responses to SARS-CoV-2 persist in the pharyngeal lymphoid tissue of children

Most studies of adaptive immunity to SARS-CoV-2 infection focus on peripheral blood, which may not fully reflect immune responses at the site of infection. Using samples from 110 children undergoing tonsillectomy and adenoidectomy during the COVID-19 pandemic, we identified 24 samples with evidence of previous SARS-CoV-2 infection, including neutralizing antibodies in serum and SARS-CoV-2-specific germinal center and memory B cells in the tonsils and adenoids. Single-cell B cell receptor (BCR) sequencing indicated virus-specific BCRs were class-switched and somatically hypermutated, with overlapping clones in the two tissues. Expanded T cell clonotypes were found in tonsils, adenoids and blood post-COVID-19, some with CDR3 sequences identical to previously reported SARS-CoV-2-reactive T cell receptors (TCRs). Pharyngeal tissues from COVID-19-convalescent children showed persistent expansion of germinal center and antiviral lymphocyte populations associated with interferon (IFN)-γ-type responses, particularly in the adenoids, and viral RNA in both tissues. Our results provide evidence for persistent tissue-specific immunity to SARS-CoV-2 in the upper respiratory tract of children after infection.

1072. SARS-CoV-2 Antibody Levels Associate with Neutrophil Activation

Background

COVID-19 disease severity and outcomes have been linked to high antibody titers and a dysregulated neutrophil immune response. Here we query associations and connections between the endogenous SARS-CoV-2 antibody response and neutrophil activation in COVID-19.

Methods

Baseline serum or plasma samples from 57 patients hospitalized on oxygen with COVID-19 were used to perform; 1) quantitative measurements of SARS-CoV-2 specific antibodies using a luciferase-based immunoprecipitation system assay, 2) quantitative measurements of neutrophil specific biomarkers using Luminex technology, and 3) neutrophil extracellular traps (NETs) as measured by myeloperoxidase-DNA (MPO-DNA) complexes by ELISA. Absolute neutrophil count (ANC) and immature granulocyte count (IGC) were measured from complete blood counts (CBC). Antibody levels were compared by disease severity using Wilcoxon rank-sum test and correlations were generated between antibody levels and neutrophil activation markers using Spearman’s correlation (SC).

Results

In a cohort of hospitalized patients, severe/critical COVID-19 was associated with higher levels of nucleocapsid-IgA (p=0.011) as well as spike-IgG (p= 0.0007) compared to moderate disease, while spike-IgA and nucleocapsid-IgG showed similar associations, trending towards significance (Figure 1A). Levels of IgG-spike and IgG-nucleocapsid both had significant correlations with the ANC (SC 0.33, p = 0.029; SC 0.38 p = 0.012). All four antibody titers showed strong correlations with IGC, lactoferrin and lipocalin-2, evidence of emergency granulopoiesis. Further, S100A9, a component calprotectin correlated with spike-IgG and nucleocapsid-IgA levels (SC 0.29, p = 0.030, SC 0.29 p = 0.029). Lastly, we found circulating NETs correlated with spike IgA levels (SC 0.38 p = 0.006), and its correlations with IgG-spike and IgA-nucleocapsid additionally approached significance with NETs levels as well (Figure 1B).

Antibody Levels Correlate with Disease Severity and Neutrophil Activation Markers

Figure 1: A) Levels of anti-Spike and anti-Nucleocapsid IgA and IgG levels measured in the serum of 57 unvaccinated hospitalized COVID-19 patients. Moderate illness represents ordinal scale 5 requiring low flow oxygen, while severe/critical patients represent ordinal scale 6 and 7, requiring high flow oxygen, non-invasive or mechanical ventilation, respectively. P values are compared by a Wilcoxon ranked sum test. B) Heatmap showing Spearman correlations between levels of anti-Spike and anti-Nucleocapsid IgA and IgG and markers of neutrophil activation. P values for individual correlations are represented in parentheses. MPO (myeloperoxidase), ANC (absolute neutrophil count), S100A9 (S100 calcium binding protein A9).

Conclusion

Higher anti-spike and anti-nucleocapsid IgG and IgA levels associate with more severe COVID-19 illness. Further, endogenous SARS-CoV-2 specific antibody levels associate with markers of emergency granulopoiesis and neutrophil activation. Inhibiting antibody mediated neutrophil activation may improve outcomes in COVID-19.

Disclosures

All Authors: No reported disclosures.

1044. Identification and Characterization of an Unconventional NK Subset in COVID-19

Background

Coronavirus Disease 2019 (COVID-19) caused by the SARS-CoV-2 virus is associated with dysregulation in the innate immune response including NK cells. NK cells are integral in the innate immune response against viral infections. Canonical NK cells are classified as CD56dim CD16+ and CD56bright CD16-. An unconventional subset of CD56dim CD16- NK cells has previously been identified in COVID-19 that is not present in other viral infections. Here we characterize phenotypic changes in the NK cells of patients with severe COVID-19 as work towards determining the functional status of this unconventional subset.

Methods

Peripheral blood mononuclear cells (PBMCs) and plasma were isolated from healthy donors (n=5) and patients with severe COVID-19 on Extra Corporeal Membrane Oxygenation (ECMO) (n=15). Primary NK cells were stimulated in vitro with plasma from patients with severe COVID-19 or healthy donors. Flow cytometry was used to phenotype the NK cells. A separate cohort of PBMC samples (n=7) from patients requiring hospitalization for COVID-19 underwent Cellular Indexing of Transcriptomes and Epitopes by Sequencing (CITE-Seq) analysis.

Results

The CD56bright CD16- NK subset was expanded in PBMCs from patients with severe COVID-19 as compared to healthy controls. CITE-Seq demonstrated that NK cells without surface CD16 clustered separately based on transcriptional profiling and did express FCGR3A at the translational level. Stimulation with COVID-19 plasma recapitulated the loss of CD16 from primary human NK cells and led to increased activity of Caspase 3/7. Figure 1.NK cells shift from the CD56dim CD16+ subset to the CD56dim CD16-subset in patients with severe COVID-19.

a) Representative gating of NK cell subsets by Flow Cytometry in healthy and COVID-19 patient peripheral blood mononuclear cells (PBMCs). b) Percentage of total NK cells belonging to a particular cell subset compared between healthy donor samples (n=4) and COVID-19 patient samples (n=8). Data points represent an individual patient sample. Error bars represent the standard deviation of the mean. Differences between groups was analyzed using a two tailed t-test. *: p&lt; 0.05, ns: not significant Figure 2.NK cells shift from the CD56dim CD16+ subset to the CD56dim CD16-subset after stimulation with COVID-19 plasma in vitro

a) Representative gating of NK cell subsets by Flow Cytometry analysis in healthy donor NK cells stimulated by healthy plasma and COVID-19 patient plasma. b)Relative change in percentage of total NK cells belonging to a particular cell subset compared between healthy donor plasma (n=6)and COVID-19 patient plasma (n=15) stimulation conditions. Error bars represent the standard deviation of the mean and the difference between groups was analyzed using a two-tailed T-test. **: p&lt; 0.01, ***: p&lt; 0.001, ns: not significant.

Conclusion

We demonstrate and characterize a nonclassical population of CD56dim CD16- NK cells that are present in patients with severe COVID-19 and replicate this phenotype in vitro. Reproduction of this in vivo phenotype in an in vitro system will allow for additional studies on the functional state of NK cell subsets in COVID-19. The presence of this NK cell population may reflect a dysregulated innate immune response and immunopathogenesis of COVID-19.

Disclosures

All Authors: No reported disclosures.

Prevalence and Mechanisms of Mucus Accumulation in COVID-19 Lung Disease

Rationale: The incidence and sites of mucus accumulation and molecular regulation of mucin gene expression in coronavirus (COVID-19) lung disease have not been reported. Objectives: To characterize the incidence of mucus accumulation and the mechanisms mediating mucin hypersecretion in COVID-19 lung disease. Methods: Airway mucus and mucins were evaluated in COVID-19 autopsy lungs by Alcian blue and periodic acid-Schiff staining, immunohistochemical staining, RNA in situ hybridization, and spatial transcriptional profiling. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected human bronchial epithelial (HBE) cultures were used to investigate mechanisms of SARS-CoV-2-induced mucin expression and synthesis and test candidate countermeasures. Measurements and Main Results: MUC5B and variably MUC5AC RNA concentrations were increased throughout all airway regions of COVID-19 autopsy lungs, notably in the subacute/chronic disease phase after SARS-CoV-2 clearance. In the distal lung, MUC5B-dominated mucus plugging was observed in 90% of subjects with COVID-19 in both morphologically identified bronchioles and microcysts, and MUC5B accumulated in damaged alveolar spaces. SARS-CoV-2-infected HBE cultures exhibited peak titers 3 days after inoculation, whereas induction of MUC5B/MUC5AC peaked 7-14 days after inoculation. SARS-CoV-2 infection of HBE cultures induced expression of epidermal growth factor receptor (EGFR) ligands and inflammatory cytokines (e.g., IL-1α/β) associated with mucin gene regulation. Inhibiting EGFR/IL-1R pathways or administration of dexamethasone reduced SARS-CoV-2-induced mucin expression. Conclusions: SARS-CoV-2 infection is associated with a high prevalence of distal airspace mucus accumulation and increased MUC5B expression in COVID-19 autopsy lungs. HBE culture studies identified roles for EGFR and IL-1R signaling in mucin gene regulation after SARS-CoV-2 infection. These data suggest that time-sensitive mucolytic agents, specific pathway inhibitors, or corticosteroid administration may be therapeutic for COVID-19 lung disease.

SARS-CoV-2 infection and persistence in the human body and brain at autopsy

Coronavirus disease 2019 (COVID-19) is known to cause multi-organ dysfunction1-3 during acute infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), with some patients experiencing prolonged symptoms, termed post-acute sequelae of SARS-CoV-2 (refs. 4,5). However, the burden of infection outside the respiratory tract and time to viral clearance are not well characterized, particularly in the brain3,6-14. Here we carried out complete autopsies on 44 patients who died with COVID-19, with extensive sampling of the central nervous system in 11 of these patients, to map and quantify the distribution, replication and cell-type specificity of SARS-CoV-2 across the human body, including the brain, from acute infection to more than seven months following symptom onset. We show that SARS-CoV-2 is widely distributed, predominantly among patients who died with severe COVID-19, and that virus replication is present in multiple respiratory and non-respiratory tissues, including the brain, early in infection. Further, we detected persistent SARS-CoV-2 RNA in multiple anatomic sites, including throughout the brain, as late as 230 days following symptom onset in one case. Despite extensive distribution of SARS-CoV-2 RNA throughout the body, we observed little evidence of inflammation or direct viral cytopathology outside the respiratory tract. Our data indicate that in some patients SARS-CoV-2 can cause systemic infection and persist in the body for months.

Anti-PF4 antibodies associated with disease severity in COVID-19

Severe COVID-19 is characterized by a prothrombotic state associated with thrombocytopenia, with microvascular thrombosis being almost invariably present in the lung and other organs at postmortem examination. We evaluated the presence of antibodies to platelet factor 4 (PF4)-polyanion complexes using a clinically validated immunoassay in 100 hospitalized patients with COVID-19 with moderate or severe disease (World Health Organization score, 4 to 10), 25 patients with acute COVID-19 visiting the emergency department, and 65 convalescent individuals. Anti-PF4 antibodies were detected in 95 of 100 hospitalized patients with COVID-19 (95.0%) irrespective of prior heparin treatment, with a mean optical density value of 0.871 ± 0.405 SD (range, 0.177 to 2.706). In contrast, patients hospitalized for severe acute respiratory disease unrelated to COVID-19 had markedly lower levels of the antibodies. In a high proportion of patients with COVID-19, levels of all three immunoglobulin (Ig) isotypes tested (IgG, IgM, and IgA) were simultaneously elevated. Antibody levels were higher in male than in female patients and higher in African Americans and Hispanics than in White patients. Anti-PF4 antibody levels were correlated with the maximum disease severity score and with significant reductions in circulating platelet counts during hospitalization. In individuals convalescent from COVID-19, the antibody levels returned to near-normal values. Sera from patients with COVID-19 induced higher levels of platelet activation than did sera from healthy blood donors, but the results were not correlated with the levels of anti-PF4 antibodies. These results demonstrate that the vast majority of patients with severe COVID-19 develop anti-PF4 antibodies, which may play a role in the clinical complications of COVID-19.

Antiviral innate immunity is diminished in the upper respiratory tract of severe COVID-19 patients

Understanding early innate immune responses to coronavirus disease 2019 (COVID-19) is crucial to developing targeted therapies to mitigate disease severity. Severe acute respiratory syndrome coronavirus (SARS-CoV)-2 infection elicits interferon expression leading to transcription of IFN-stimulated genes (ISGs) to control viral replication and spread. SARS-CoV-2 infection also elicits NF-κB signaling which regulates inflammatory cytokine expression contributing to viral control and likely disease severity. Few studies have simultaneously characterized these two components of innate immunity to COVID-19. We designed a study to characterize the expression of interferon alpha-2 (IFNA2) and interferon beta-1 (IFNB1), both type-1 interferons (IFN-1), interferon-gamma (IFNG), a type-2 interferon (IFN-2), ISGs, and NF-κB response genes in the upper respiratory tract (URT) of patients with mild (outpatient) versus severe (hospitalized) COVID-19. Further, we characterized the weekly dynamics of these responses in the upper and lower respiratory tracts (LRTs) and blood of severe patients to evaluate for compartmental differences. We observed significantly increased ISG and NF-κB responses in the URT of mild compared with severe patients early during illness. This pattern was associated with increased IFNA2 and IFNG expression in the URT of mild patients, a trend toward increased IFNB1-expression and significantly increased STING/IRF3/cGAS expression in the URT of severe patients. Our by-week across-compartment analysis in severe patients revealed significantly higher ISG responses in the blood compared with the URT and LRT of these patients during the first week of illness, despite significantly lower expression of IFNA2, IFNB1, and IFNG in blood. NF-κB responses, however, were significantly elevated in the LRT compared with the URT and blood of severe patients during peak illness (week 2). Our data support that severe COVID-19 is associated with impaired interferon signaling in the URT during early illness and robust pro-inflammatory responses in the LRT during peak illness.

Multicenter analysis of neutrophil extracellular trap dysregulation in adult and pediatric COVID-19

Dysregulation in neutrophil extracellular trap (NET) formation and degradation may play a role in the pathogenesis and severity of COVID-19; however, its role in the pediatric manifestations of this disease, including multisystem inflammatory syndrome in children (MIS-C) and chilblain-like lesions (CLLs), otherwise known as “COVID toes,” remains unclear. Studying multinational cohorts, we found that, in CLLs, NETs were significantly increased in serum and skin. There was geographic variability in the prevalence of increased NETs in MIS-C, in association with disease severity. MIS-C and CLL serum samples displayed decreased NET degradation ability, in association with C1q and G-actin or anti-NET antibodies, respectively, but not with genetic variants of DNases. In adult COVID-19, persistent elevations in NETs after disease diagnosis were detected but did not occur in asymptomatic infection. COVID-19–affected adults displayed significant prevalence of impaired NET degradation, in association with anti-DNase1L3, G-actin, and specific disease manifestations, but not with genetic variants of DNases. NETs were detected in many organs of adult patients who died from COVID-19 complications. Infection with the Omicron variant was associated with decreased NET levels when compared with other SARS-CoV-2 strains. These data support a role for NETs in the pathogenesis and severity of COVID-19 in pediatric and adult patients.

Complement activates an autocrine Vitamin D system that recruits a defined transcription factor network to shut down pro-inflammatory programs of Th1 cells

Background

Pro-inflammatory CD4+ T helper (Th)1 cells clear pathogens effectively but cause excessive tissue injury if not shut down appropriately. The complement (C’) system both induces Th1 differentiation and their shutdown, but the mechanisms regulating orderly shutdown remain unknown.

Hypothesis

C’ receptor engagement recruits transcriptional regulators essential to Th1 shutdown.

Methods

Multi-modal profiling of activated, or patient-derived Th cells, psoriatic skin, and SARS-CoV2-infected tissues was carried out by epigenome profiling, RNAseq, network modeling, phospho-arrays, confocal, and regulator knockdown.

Results

C’ receptor signaling induced the vitamin D (VitD) receptor (VDR) and CYP27B1, the enzyme that activates VitD, allowing T cells to both fully activate and respond to VitD. Active VitD shut down IFN-γ production by Th1 cells and induced IL-10. This was mediated by activation of IL-6 production by T cells and signaling through STAT3. Mechanistically, VitD reprogrammed the Th1 transcriptomes by forming super-enhancers and recruiting a transcription factor (TF) network consisting of VDR, c-JUN, STAT3, and BACH2. We mapped genome-wide targets of these TFs by CUT&RUN/Tag. As proof of principal, psoriatic skin treated with VitD induced BACH2 in Th cells, and genetic deficiency of either BACH2 or STAT3 inhibited IL-10 produced in response to VitD. Bronchoalveolar lavage fluid of COVID-19 patients, a C’-rich environment, showed excessive Th1 skewing and perturbation of the VitD-regulated program of genes.

Conclusion

We identified a C’-recruited autocrine VitD system as key to Th1 shutdown and indicate the potential for adjunct therapy with VitD in hyper-inflammatory syndromes, e.g. COVID-19.

This work was supported by the Wellcome Trust (grant 097261/Z/11/Z to B.A.), the Crohn’s and Colitis Foundation of America (grant CCFA no. 3765 — CCFA genetics initiative to A.L.), British Heart Foundation (grant RG/13/12/30395 to G.L.), the National Institute of General Medical Sciences (R35GM138283 to M.K.), the Showalter Trust (research award to M.K.), German Research Foundation (DFG scholarship to T.F.; FR 3851/2-1), the NIDDK (DK12262401A1 to D.P.) and the National Agency of Research and Development of Chile (grant PAI79170073 to E.N.L.). Research was also supported by the National Institute for Health Research (NIHR) Biomedical Research Centre based at Guy’s and St Thomas’ NHS Foundation Trust and King’s College London and/or the NIHR Clinical Research Facility. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health. This research was supported (in part) by the Intramural Research Programs of the NIDDK (project no. ZIA/DK075149 to B.A), the National Heart, Lung and Blood Institute (project nos. ZIA/Hl006223 to C.K. and ZIA/HL006193 to N.M.), the NIAID (project no. ZIA/AI001175 to M.S.L.) of the NIH. D.C. is supported by an NIH Office of Dietary Supplements research scholar award.

Evaluation of viral load in patients with Ebola virus disease in Liberia: a retrospective observational study

Background

Viral load in patients with Ebola virus disease affects case fatality rate and is an important parameter used for diagnostic cutoffs, stratification in randomised controlled trials, and epidemiological studies. However, viral load in Ebola virus disease is currently estimated using numerous different assays and protocols that were not developed or validated for this purpose. Here, our aim was to conduct a laboratory-based re-evaluation of the viral loads of a large cohort of Liberian patients with Ebola virus disease and analyse these data in the broader context of the west Africa epidemic.

Methods

In this retrospective observational study, whole blood samples from patients at the Eternal Love Winning Africa Ebola treatment unit (Monrovia, Liberia) were re-extracted with an optimised protocol and analysed by droplet digital PCR (ddPCR) using a novel semi-strand specific assay to measure viral load. To allow for more direct comparisons, the ddPCR viral loads were also back-calculated to cycle threshold (C_t) values. The new viral load data were then compared with the C_t values from the original diagnostic quantitative RT-PCR (qRT-PCR) testing to identify differing trends and discrepancies.

Findings

Between Aug 28 and Dec 18, 2014, 727 whole blood samples from 528 individuals were collected. 463 (64%) were first-draw samples and 409 (56%) were from patients positive for Ebola virus (EBOV), species Zaire ebolavirus. Of the 307 first-draw EBOV-positive samples, 127 (41%) were from survivors and 180 (59%) were from non-survivors; 155 (50%) were women, 145 (47%) were men, and seven (2%) were not recorded, and the mean age was 29·3 (SD 15·0) years for women and 31·8 (SD 14·8) years for men. Survivors had significantly lower mean viral loads at presentation than non-survivors in both the reanalysed dataset (5·61 [95% CI 5·34–5·87] vs 7·19 [6·99–7·38] log₁₀ EBOV RNA copies per mL; p<0·0001) and diagnostic dataset (C_t value 28·72 [27·97–29·47] vs 26·26 [25·72–26·81]; p<0·0001). However, the prognostic capacity of viral load increased with the reanalysed dataset (odds ratio [OR] of death 8·06 [95% CI 4·81–13·53], p<0·0001 for viral loads above 6·71 log₁₀ EBOV RNA copies per mL vs OR of death 2·02 [1·27–3·20], p=0·0028 for C_t values below 27·37). Diagnostic qRT-PCR significantly (p<0·0001) underestimated viral load in both survivors and non-survivors (difference in diagnostic C_t value minus laboratory C_t value of 1·79 [95% CI 1·16–2·43] for survivors and 5·15 [4·43–5·87] for non-survivors). Six samples that were reported negative by diagnostic testing were found to be positive upon reanalysis and had high viral loads.

Interpretation

Inaccurate viral load estimation from diagnostic C_t values is probably multifactorial; however, unaddressed PCR inhibition from tissue damage in patients with fulminant Ebola virus disease could largely account for the discrepancies observed in our study. Testing protocols for Ebola virus disease require further standardisation and validation to produce accurate viral load estimates, minimise false negatives, and allow for reliable epidemiological investigation.

Robust, persistent adaptive immune responses to SARS-CoV-2 in the oropharyngeal lymphoid tissue of children

SARS-CoV-2 infection triggers adaptive immune responses from both T and B cells. However, most studies focus on peripheral blood, which may not fully reflect immune responses in lymphoid tissues at the site of infection. To evaluate both local and systemic adaptive immune responses to SARS-CoV-2, we collected peripheral blood, tonsils, and adenoids from 110 children undergoing tonsillectomy/adenoidectomy during the COVID-19 pandemic and found 24 with evidence of prior SARS-CoV-2 infection, including detectable neutralizing antibodies against multiple viral variants. We identified SARS-CoV-2-specific germinal center (GC) and memory B cells; single cell BCR sequencing showed that these virus-specific B cells were class-switched and somatically hypermutated, with overlapping clones in the adenoids and tonsils. Oropharyngeal tissues from COVID-19-convalescent children showed persistent expansion of GC and anti-viral lymphocyte populations associated with an IFN-γ-type response, with particularly prominent changes in the adenoids, as well as evidence of persistent viral RNA in both tonsil and adenoid tissues of many participants. Our results show robust, tissue-specific adaptive immune responses to SARS-CoV-2 in the upper respiratory tract of children weeks to months after acute infection, providing evidence of persistent localized immunity to this respiratory virus.

Multicenter analysis of neutrophil extracellular trap dysregulation in adult and pediatric COVID-19

Dysregulation in neutrophil extracellular trap (NET) formation and degradation may play a role in the pathogenesis and severity of COVID-19; however, its role in the pediatric manifestations of this disease including MIS-C and chilblain-like lesions (CLL), otherwise known as "COVID toes", remains unclear. Studying multinational cohorts, we found that, in CLL, NETs were significantly increased in serum and skin. There was geographic variability in the prevalence of increased NETs in MIS-C, in association with disease severity. MIS-C and CLL serum samples displayed decreased NET degradation ability, in association with C1q and G-actin or anti-NET antibodies, respectively, but not with genetic variants of DNases. In adult COVID-19, persistent elevations in NETs post-disease diagnosis were detected but did not occur in asymptomatic infection. COVID-19-affected adults displayed significant prevalence of impaired NET degradation, in association with anti-DNase1L3, G-actin, and specific disease manifestations, but not with genetic variants of DNases. NETs were detected in many organs of adult patients who died from COVID-19 complications. Infection with the Omicron variant was associated with decreased levels of NETs when compared to other SARS-CoV-2 strains. These data support a role for NETs in the pathogenesis and severity of COVID-19 in pediatric and adult patients.

Summary

NET formation and degradation are dysregulated in pediatric and symptomatic adult patients with various complications of COVID-19, in association with disease severity. NET degradation impairments are multifactorial and associated with natural inhibitors of DNase 1, G-actin and anti-DNase1L3 and anti-NET antibodies. Infection with the Omicron variant is associated with decreased levels of NETs when compared to other SARS-CoV-2 strains.

SARS-CoV-2 mRNA vaccine induced higher antibody affinity and IgG titers against variants of concern in post-partum vs non-post-partum women

BACKGROUND

Limited knowledge exists in post-partum women regarding durability of SARS-CoV-2 vaccine-induced antibody responses and their neutralising ability against SARS-CoV-2 variants of concern (VOC).

METHODS

We elucidated longitudinal mRNA vaccination-induced antibody profiles of 13 post-partum and 13 non-post-partum women (control).

FINDINGS

The antibody neutralisation titres against SARS-CoV-2 WA-1 strain were comparable between post-partum and non-post-partum women and these levels were sustained up to four months post-second vaccination in both groups. However, neutralisation titers declined against several VOCs, including Beta and Delta. Higher antibody binding was observed against SARS-CoV-2 receptor-binding domain (RBD) mutants with key VOC amino acids when tested with post-second vaccination plasma from post-partum women compared with controls. Importantly, post-vaccination plasma antibody affinity against VOCs RBDs was significantly higher in post-partum women compared with controls.

INTERPRETATION

This study demonstrates that there is a differential vaccination-induced immune responses in post-partum women compared with non-post-partum women, which could help inform future vaccination strategies for these groups.

FUNDING

The antibody characterisation work described in this manuscript was supported by FDA's Medical Countermeasures Initiative (MCMi) grant #OCET 2021-1565 to S.K and intramural FDA-CBER COVID-19 supplemental funds.

Autocrine vitamin D signaling switches off pro-inflammatory programs of TH1 cells

The molecular mechanisms governing orderly shutdown and retraction of CD4⁺ type 1 helper T (T_H1) cell responses remain poorly understood. Here we show that complement triggers contraction of T_H1 responses by inducing intrinsic expression of the vitamin D (VitD) receptor and the VitD-activating enzyme CYP27B1, permitting T cells to both activate and respond to VitD. VitD then initiated the transition from pro-inflammatory interferon-γ⁺ T_H1 cells to suppressive interleukin-10⁺ cells. This process was primed by dynamic changes in the epigenetic landscape of CD4⁺ T cells, generating super-enhancers and recruiting several transcription factors, notably c-JUN, STAT3 and BACH2, which together with VitD receptor shaped the transcriptional response to VitD. Accordingly, VitD did not induce interleukin-10 expression in cells with dysfunctional BACH2 or STAT3. Bronchoalveolar lavage fluid CD4⁺ T cells of patients with COVID-19 were T_H1-skewed and showed de-repression of genes downregulated by VitD, from either lack of substrate (VitD deficiency) and/or abnormal regulation of this system.

Evidence of SARS-CoV-2-Specific T-Cell-Mediated Myocarditis in a MIS-A Case

A 26-year-old otherwise healthy man died of fulminant myocarditis. Nasopharyngeal specimens collected premortem tested negative for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Histopathological evaluation of the heart showed myocardial necrosis surrounded by cytotoxic T-cells and tissue-repair macrophages. Myocardial T-cell receptor (TCR) sequencing revealed hyper-dominant clones with highly similar sequences to TCRs that are specific for SARS-CoV-2 epitopes. SARS-CoV-2 RNA was detected in the gut, supporting a diagnosis of multisystem inflammatory syndrome in adults (MIS-A). Molecular targets of MIS-associated inflammation are not known. Our data indicate that SARS-CoV-2 antigens selected high-frequency T-cell clones that mediated fatal myocarditis.

Fostamatinib for the Treatment of Hospitalized Adults With Coronavirus Disease 2019: A Randomized Trial

BACKGROUND

Coronavirus disease 2019 (COVID-19) requiring hospitalization is characterized by robust antibody production, dysregulated immune response, and immunothrombosis. Fostamatinib is a novel spleen tyrosine kinase inhibitor that we hypothesize will ameliorate Fc activation and attenuate harmful effects of the anti-COVID-19 immune response.

METHODS

We conducted a double-blind, randomized, placebo-controlled trial in hospitalized adults requiring oxygen with COVID-19 where patients receiving standard of care were randomized to receive fostamatinib or placebo. The primary outcome was serious adverse events by day 29.

RESULTS

A total of 59 patients underwent randomization (30 to fostamatinib and 29 to placebo). Serious adverse events occurred in 10.5% of patients in the fostamatinib group compared with 22% in placebo (P = .2). Three deaths occurred by day 29, all receiving placebo. The mean change in ordinal score at day 15 was greater in the fostamatinib group (-3.6 ± 0.3 vs -2.6 ± 0.4, P = .035) and the median length in the intensive care unit was 3 days in the fostamatinib group vs 7 days in placebo (P = .07). Differences in clinical improvement were most evident in patients with severe or critical disease (median days on oxygen, 10 vs 28, P = .027). There were trends toward more rapid reductions in C-reactive protein, D-dimer, fibrinogen, and ferritin levels in the fostamatinib group.

CONCLUSION

For COVID-19 requiring hospitalization, the addition of fostamatinib to standard of care was safe and patients were observed to have improved clinical outcomes compared with placebo. These results warrant further validation in larger confirmatory trials.

CLINICAL TRIALS REGISTRATION

Clinicaltrials.gov, NCT04579393.

The Impact of Corticosteroids on Secondary Infection and Mortality in Critically Ill COVID-19 Patients

BACKGROUND

Corticosteroids are part of the treatment guidelines for COVID-19 and have been shown to improve mortality. However, the impact corticosteroids have on the development of secondary infection in COVID-19 is unknown. We sought to define the rate of secondary infection in critically ill patients with COVID-19 and determine the effect of corticosteroid use on mortality in critically ill patients with COVID-19.

STUDY DESIGN AND METHODS

One hundred and thirty-five critically ill patients with COVID-19 admitted to the Intensive Care Unit (ICU) at the University of Maryland Medical Center were included in this single-center retrospective analysis. Demographics, symptoms, culture data, use of COVID-19 directed therapies, and outcomes were abstracted from the medical record. The primary outcomes were secondary infection and mortality. Proportional hazards models were used to determine the time to secondary infection and the time to death.

RESULTS

The proportion of patients with secondary infection was 63%. The likelihood of developing secondary infection was not significantly impacted by the administration of corticosteroids (HR 1.45, CI 0.75-2.82, P = 0.28). This remained consistent in sub-analysis looking at bloodstream, respiratory, and urine infections. Secondary infection had no significant impact on the likelihood of 28-day mortality (HR 0.66, CI 0.33-1.35, P = 0.256). Corticosteroid administration significantly reduced the likelihood of 28-day mortality (HR 0.27, CI 0.10-0.72, P = 0.01).

CONCLUSION

Corticosteroids are an important and lifesaving pharmacotherapeutic option in critically ill patients with COVID-19, which have no impact on the likelihood of developing secondary infections.

Pre-vaccination and early B cell signatures predict antibody response to SARS-CoV-2 mRNA vaccine

SARS-CoV-2 mRNA vaccines are highly effective, although weak antibody responses are seen in some individuals with correlates of immunity that remain poorly understood. Here we longitudinally dissected antibody, plasmablast, and memory B cell (MBC) responses to the two-dose Moderna mRNA vaccine in SARS-CoV-2-uninfected adults. Robust, coordinated IgA and IgG antibody responses were preceded by bursts of spike-specific plasmablasts after both doses, but earlier and more intensely after dose two. Distinct antigen-specific MBC populations also emerged post-vaccination with varying kinetics. We identified antigen non-specific pre-vaccination MBC and post-vaccination plasmablasts after dose one and their spike-specific counterparts early after dose two that correlated with subsequent antibody levels. These baseline and response signatures can thus provide early indicators of serological efficacy and explain response variability in the population.

Nonhuman primates exposed to Zika virus in utero are not protected against reinfection at 1 year postpartum

There is limited information about the impact of Zika virus (ZIKV) exposure in utero on the anti-ZIKV immune responses of offspring. We infected six rhesus macaque dams with ZIKV early or late in pregnancy and studied four of their offspring over the course of a year postpartum. Despite evidence of ZIKV exposure in utero, we observed no structural brain abnormalities in the offspring. We detected infant-derived ZIKV-specific immunoglobulin A antibody responses and T cell memory responses during the first year postpartum in the two offspring born to dams infected with ZIKV early in pregnancy. Critically, although the infants had acquired some immunological memory of ZIKV, it was not sufficient to protect them against reinfection with ZIKV at 1 year postpartum. The four offspring reexposed to ZIKV at 1 year postpartum all survived but exhibited acute viremia and viral tropism to lymphoid tissues; three of four reexposed offspring exhibited spinal cord pathology. These data suggest that macaque infants born to dams infected with ZIKV during pregnancy remain susceptible to postnatal infection and consequent neuropathology.

Fostamatinib Inhibits Neutrophils Extracellular Traps Induced by COVID-19 Patient Plasma: A Potential Therapeutic

Neutrophil extracellular traps (NETs) contribute to immunothrombosis and have been associated with mortality in coronavirus disease 2019 (COVID-19). We stimulated donor neutrophils with plasma from patients with COVID-19 and demonstrated that R406 can abrogate the release of NETs. These data provide evidence for how fostamatinib may mitigate neutrophil-associated mechanisms contributing to COVID-19 immunopathogenesis.

High-throughput, single-copy sequencing reveals SARS-CoV-2 spike variants coincident with mounting humoral immunity during acute COVID-19

Tracking evolution of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) within infected individuals will help elucidate coronavirus disease 2019 (COVID-19) pathogenesis and inform use of antiviral interventions. In this study, we developed an approach for sequencing the region encoding the SARS-CoV-2 virion surface proteins from large numbers of individual virus RNA genomes per sample. We applied this approach to the WA-1 reference clinical isolate of SARS-CoV-2 passaged in vitro and to upper respiratory samples from 7 study participants with COVID-19. SARS-CoV-2 genomes from cell culture were diverse, including 18 haplotypes with non-synonymous mutations clustered in the spike NH2-terminal domain (NTD) and furin cleavage site regions. By contrast, cross-sectional analysis of samples from participants with COVID-19 showed fewer virus variants, without structural clustering of mutations. However, longitudinal analysis in one individual revealed 4 virus haplotypes bearing 3 independent mutations in a spike NTD epitope targeted by autologous antibodies. These mutations arose coincident with a 6.2-fold rise in serum binding to spike and a transient increase in virus burden. We conclude that SARS-CoV-2 exhibits a capacity for rapid genetic adaptation that becomes detectable in vivo with the onset of humoral immunity, with the potential to contribute to delayed virologic clearance in the acute setting.

High-Throughput, Single-Copy Sequencing Reveals SARS-CoV-2 Spike Variants Coincident with Mounting Humoral Immunity during Acute COVID-19

Tracking evolution of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) within infected individuals will help elucidate coronavirus disease 2019 (COVID-19) pathogenesis and inform use of antiviral interventions. In this study, we developed an approach for sequencing the region encoding the SARS-CoV-2 virion surface proteins from large numbers of individual virus RNA genomes per sample. We applied this approach to the WA-1 reference clinical isolate of SARS-CoV-2 passaged in vitro and to upper respiratory samples from 7 study participants with COVID-19. SARS-CoV-2 genomes from cell culture were diverse, including 18 haplotypes with non-synonymous mutations clustered in the spike NH 2 -terminal domain (NTD) and furin cleavage site regions. By contrast, cross-sectional analysis of samples from participants with COVID-19 showed fewer virus variants, without structural clustering of mutations. However, longitudinal analysis in one individual revealed 4 virus haplotypes bearing 3 independent mutations in a spike NTD epitope targeted by autologous antibodies. These mutations arose coincident with a 6.2-fold rise in serum binding to spike and a transient increase in virus burden. We conclude that SARS-CoV-2 exhibits a capacity for rapid genetic adaptation that becomes detectable in vivo with the onset of humoral immunity, with the potential to contribute to delayed virologic clearance in the acute setting.

AUTHOR SUMMARY

Mutant sequences of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) arising during any individual case of coronavirus disease 2019 (COVID-19) could theoretically enable the virus to evade immune responses or antiviral therapies that target the predominant infecting virus sequence. However, commonly used sequencing technologies are not optimally designed to detect variant virus sequences within each sample. To address this issue, we developed novel technology for sequencing large numbers of individual SARS-CoV-2 genomic RNA molecules across the region encoding the virus surface proteins. This technology revealed extensive genetic diversity in cultured viruses from a clinical isolate of SARS-CoV-2, but lower diversity in samples from 7 individuals with COVID-19. Importantly, concurrent analysis of paired serum samples in selected individuals revealed relatively low levels of antibody binding to the SARS-CoV-2 spike protein at the time of initial sequencing. With increased serum binding to spike protein, we detected multiple SARS-CoV-2 variants bearing independent mutations in a single epitope, as well as a transient increase in virus burden. These findings suggest that SARS-CoV-2 replication creates sufficient virus genetic diversity to allow immune-mediated selection of variants within the time frame of acute COVID-19. Large-scale studies of SARS-CoV-2 variation and specific immune responses will help define the contributions of intra-individual SARS-CoV-2 evolution to COVID-19 clinical outcomes and antiviral drug susceptibility.

In Utero Severe Acute Respiratory Syndrome Coronavirus 2 Infection

Evidence for in utero transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is growing but not definitive. We present a case of neonatal infection that supports in utero transmission of SARS-CoV-2 and provides insight into the hematogenous spread from mother to fetus.

Longitudinal Human Antibody Repertoire against Complete Viral Proteome from Ebola Virus Survivor Reveals Protective Sites for Vaccine Design

Evolution of antibody repertoire against the Ebola virus (EBOV) proteome was characterized in an acutely infected patient receiving supportive care alone to elucidate virus-host interactions over time. Differential kinetics are observed for IgM-IgG-IgA epitope diversity, antibody binding, and affinity maturation to EBOV proteins. During acute illness, antibodies predominate to VP40 and glycoprotein (GP). At day 13 of clinical illness, a marked increase in antibody titers to most EBOV proteins and affinity maturation to GP is associated with rapid decline in viral replication and illness severity. At one year, despite undetectable virus, a diverse IgM repertoire against VP40 and GP epitopes is observed suggesting occult viral persistence. Rabbit immunization experiments identify key immunodominant sites of GP, while challenge studies in mice found these epitopes induce EBOV-neutralizing antibodies and protect against lethal EBOV challenge. This study reveals markers of viral persistence and provides promising approaches for development and evaluation of vaccines and therapeutics.

Sensitivity in Detection of Antibodies to Nucleocapsid and Spike Proteins of Severe Acute Respiratory Syndrome Coronavirus 2 in Patients With Coronavirus Disease 2019

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the cause of coronavirus disease 2019 (COVID-19), is associated with respiratory-related disease and death. Assays to detect virus-specific antibodies are important to understand the prevalence of infection and the course of the immune response.

METHODS

Quantitative measurements of plasma or serum antibodies to the nucleocapsid and spike proteins were analyzed using luciferase immunoprecipitation system assays in 100 cross-sectional or longitudinal samples from patients with SARS-CoV-2 infection. A subset of samples was tested both with and without heat inactivation.

RESULTS

At >14 days after symptom onset, antibodies against SARS-CoV-2 nucleocapsid protein showed 100% sensitivity and 100% specificity, whereas antibodies to spike protein were detected with 91% sensitivity and 100% specificity. Neither antibody levels nor the rate of seropositivity were significantly reduced by heat inactivation of samples. Analysis of daily samples from 6 patients with COVID-19 showed anti-nucleocapsid and spike protein antibodies appearing between days 8 and 14 after initial symptoms. Immunocompromised patients generally had a delayed antibody response to SARS-CoV-2, compared with immunocompetent patients.

CONCLUSIONS

Antibody to the nucleocapsid protein of SARS-CoV-2 is more sensitive than spike protein antibody for detecting early infection. Analyzing heat-inactivated samples with a luciferase immunoprecipitation system assay is a safe and sensitive method for detecting SARS-CoV-2 antibodies.

Surviving Sepsis Campaign: Guidelines on the Management of Critically Ill Adults with Coronavirus Disease 2019 (COVID-19)

BACKGROUND

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of a rapidly spreading illness, Coronavirus Disease 2019 (COVID-19), affecting thousands of people around the world. Urgent guidance for clinicians caring for the sickest of these patients is needed.

METHODS

We formed a panel of 36 experts from 12 countries. All panel members completed the World Health Organization conflict of interest disclosure form. The panel proposed 53 questions that are relevant to the management of COVID-19 in the ICU. We searched the literature for direct and indirect evidence on the management of COVID-19 in critically ill patients in the ICU. We identified relevant and recent systematic reviews on most questions relating to supportive care. We assessed the certainty in the evidence using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach, then generated recommendations based on the balance between benefit and harm, resource and cost implications, equity, and feasibility. Recommendations were either strong or weak, or in the form of best practice recommendations.

RESULTS

The Surviving Sepsis Campaign COVID-19 panel issued 54 statements, of which four are best practice statements, nine are strong recommendations, and 35 are weak recommendations. No recommendation was provided for six questions. The topics were: 1) infection control, 2) laboratory diagnosis and specimens, 3) hemodynamic support, 4) ventilatory support, and 5) COVID-19 therapy.

CONCLUSION

The Surviving Sepsis Campaign COVID-19 panel issued several recommendations to help support healthcare workers caring for critically ill ICU patients with COVID-19. When available, we will provide new evidence in further releases of these guidelines.

Detection of Nucleocapsid Antibody to SARS-CoV-2 is More Sensitive than Antibody to Spike Protein in COVID-19 Patients

Background

SARS-CoV-2, the cause of coronavirus disease 2019 (COVID-19), is associated with respiratory-related morbidity and mortality. Assays to detect virus-specific antibodies are important to understand the prevalence of infection and the course of the immune response.

Methodology

Quantitative measurements of plasma or serum antibodies by luciferase immunoprecipitation assay systems (LIPS) to the nucleocapsid and spike proteins were analyzed in 100 cross-sectional or longitudinal samples from SARS-CoV-2-infected patients. A subset of samples was tested with and without heat inactivation.

Results

Fifteen or more days after symptom onset, antibodies against SARS-CoV-2 nucleocapsid protein showed 100% sensitivity and 100% specificity, while antibodies to spike protein were detected with 91% sensitivity and 100% specificity. Neither antibody levels nor the rate of seropositivity were significantly reduced by heat inactivation of samples. Analysis of daily samples from six patients with COVID-19 showed anti-nucleocapsid and spike antibodies appearing between day 8 to day 14 after initial symptoms. Immunocompromised patients generally had a delayed antibody response to SARS-CoV-2 compared to immunocompetent patients.

Conclusions

Antibody to the nucleocapsid protein of SARS-CoV-2 is more sensitive than spike protein antibody for detecting early infection. Analyzing heat-inactivated samples by LIPS is a safe and sensitive method for detecting SARS-CoV-2 antibodies.

Surviving Sepsis Campaign: guidelines on the management of critically ill adults with Coronavirus Disease 2019 (COVID-19)

Background

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of a rapidly spreading illness, Coronavirus Disease 2019 (COVID-19), affecting thousands of people around the world. Urgent guidance for clinicians caring for the sickest of these patients is needed.

Methods

We formed a panel of 36 experts from 12 countries. All panel members completed the World Health Organization conflict of interest disclosure form. The panel proposed 53 questions that are relevant to the management of COVID-19 in the ICU. We searched the literature for direct and indirect evidence on the management of COVID-19 in critically ill patients in the ICU. We identified relevant and recent systematic reviews on most questions relating to supportive care. We assessed the certainty in the evidence using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach, then generated recommendations based on the balance between benefit and harm, resource and cost implications, equity, and feasibility. Recommendations were either strong or weak, or in the form of best practice recommendations.

Results

The Surviving Sepsis Campaign COVID-19 panel issued 54 statements, of which 4 are best practice statements, 9 are strong recommendations, and 35 are weak recommendations. No recommendation was provided for 6 questions. The topics were: (1) infection control, (2) laboratory diagnosis and specimens, (3) hemodynamic support, (4) ventilatory support, and (5) COVID-19 therapy.

Conclusion

The Surviving Sepsis Campaign COVID-19 panel issued several recommendations to help support healthcare workers caring for critically ill ICU patients with COVID-19. When available, we will provide new recommendations in further releases of these guidelines.

Electronic supplementary material

The online version of this article (10.1007/s00134-020-06022-5) contains supplementary material, which is available to authorized users.

Delayed recognition of Ebola virus disease is associated with longer and larger outbreaks

The average time required to detect an Ebola virus disease (EVD) outbreak following spillover of Ebola virus (EBOV) to a primary human case has remained essentially unchanged for over 40 years, with some of the longest delays in detection occurring in recent decades. In this review, our aim was to examine the relationship between delays in detection of EVD and the duration and size of outbreaks, and we report that longer delays are associated with longer and larger EVD outbreaks. Historically, EVD outbreaks have typically been comprised of less than 100 cases (median = 60) and have lasted less than 4 months (median = 118 days). The ongoing outbreak in Democratic Republic of the Congo, together with the 2013–2016 west Africa outbreak, are stark outliers amidst these trends and had two of the longest delays in detection on record. While significant progress has been made in the development of EVD countermeasures, implementation during EVD outbreaks is problematic. Thus, EVD surveillance must be improved by the broad deployment of modern diagnostic tools, as prompt recognition of EVD has the potential to stem early transmission and ultimately limit the duration and size of outbreaks.

Modeling Challenges of Ebola Virus-Host Dynamics during Infection and Treatment

Mathematical modeling of Ebola virus (EBOV)-host dynamics during infection and treatment in vivo is in its infancy due to few studies with frequent viral kinetic data, lack of approved antiviral therapies, and limited insight into the timing of EBOV infection of cells and tissues throughout the body. Current in-host mathematical models simplify EBOV infection by assuming a single homogeneous compartment of infection. In particular, a recent modeling study assumed the liver as the largest solid organ targeted by EBOV infection and predicted that nearly all cells become refractory to infection within seven days of initial infection without antiviral treatment. We compared our observations of EBOV kinetics in multiple anatomic compartments and hepatocellular injury in a critically ill patient with Ebola virus disease (EVD) with this model's predictions. We also explored the model's predictions, with and without antiviral therapy, by recapitulating the model using published inputs and assumptions. Our findings highlight the challenges of modeling EBOV-host dynamics and therapeutic efficacy and emphasize the need for iterative interdisciplinary efforts to refine mathematical models that might advance understanding of EVD pathogenesis and treatment.

Compatibility of Maximum-Containment Virus-Inactivation Protocols With Identification of Bacterial Coinfections by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry

Diagnostics and research analyses involving samples containing maximum-containment viruses present unique challenges, and inactivation protocols compatible with downstream testing are needed. Our aim was to identify a validated viral inactivation protocol compatible with bacterial identification by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). We assessed a panel of bacteria with 6 validated maximum-containment virus-inactivation protocols and report that inactivation with TRIzol or γ-irradiation is compatible with MALDI-TOF MS. The availability, simplicity, and rapidity of TRIzol inactivation make this method the more suitable choice.