Dynamics and Heterogeneity of the Lung Immunopathology in Severe COVID-19

Background: The key impact of SARS-CoV-2 is its ability to cause a life-threatening infection in the lung. Aim(s): Using spatially resolved multiplex imaging the present study decodes the immunopathological complexity of severe COVID-19. Method(s): Autopsy lung tissue from 18 COVID-19 patients was used to map immune and structural cells in acute/exudative, intermediate and advanced diffuse alveolar damage (DAD) through multiplex immunohistochemistry and spatial statistical analyses. Cytokine profiling, viral, bacteria and fungi detection and transcriptome analyses were also performed. Result(s): All cases displayed concomitant patterns of DAD. The spatially resolved multiplex data revealed intricate patchworks of mm -size microenvironments representing distinct immunological niches. In-depth analysis of DAD areas revealed that the temporal/spatial DAD progression is associated with expansion of adaptive immune cells, macrophages, CD8 T cells, fibroblasts, angiogenesis and lymphangiogenesis. Viral load correlated positively with acute DAD and negatively with disease/hospital length. Cytokines correlated mainly with macrophages and CD8 T cells. Pro-coagulation and acute repair markers were enriched in acute DAD whereas intermediate/advanced DAD had a molecular profile of elevated humoral and innate immune responses and extracellular matrix production. Conclusion(s): Our unraveling of the spatio-temporal immunopathology in COVID-19 cases exposes the heterogeneous dynamics of acute viral infection and subsequent responses that occur side-by-side in the lungs. This complex disease feature has important implications for disease management and development of novel immunemodulatory treatments.

Differentially expressed genes in Diffuse Alveolar Damage (DAD) patterns of COVID-19

Severe COVID-19 induces DAD, a condition with temporal-spatial heterogeneity. We determined the differentially expressed genes (DEGs) in the histological patterns of DAD. Twelve fatal COVID-19 cases were classified in acute DAD (n=5) and intermediate/advanced (IA) DAD (n=7). Autopsy lung RNA was extracted from COVID-19 and 4 control cases. RNA sequencing was performed on the Illumina NovaSeq 6000. Enrichment analysis was performed with clusterProfiler using Genome-wide annotation for Human R package. GO terms and KEGG pathways were considered enriched if adjusted p<=0.05. Principal component analysis showed that IA-DAD samples were grouped, while acute DAD samples were scattered. The differential expression analysis between these two groups and the control cases revealed: 261 DEGs in the acute DAD (143 Up- and 53 Down-regulated), 244 DEGs in the IA- DAD tissues (67 Up- and 116 Down-regulated), and 61 DEGs were shared between them (45 Up- and 16 Downregulated). Patients with acute DAD had up-regulated genes related to oxidative phosphorylation, blood coagulation, megakaryocytes differentiation/regulation, and platelet degranulation/activation. Patients with IA-DAD had DEGs related to immunoglobulins and extracellular matrix. The shared up-regulated DEGs between both patterns are involved in innate and adaptive immune responses. We selected 3 DEGs in each DAD pattern for validation by realtime PCR. There were no differences in acute DAD DEGs, but DEGs overexpressed in intermediate DAD (COL3A1, IGLV3-19, IGHV1-58) were significantly higher. Genes related to thrombotic events occur at the acute stage of DAD, whereas immunoglobulin production and remodeling occur at later stages of DAD.

Correlation between lung inflammatory cells, viral load and cytokines in fatal COVID-19

SARS-CoV2 infection induces a complex interaction between virus and host immune system, activating multiple inflammatory pathways and leading to hyperinflammation, diffuse alveolar damage (DAD), ARDS, and multiorgan failure. We aimed to correlate the quantification of viral load, inflammatory cells and cytokines in lung tissue of fatal COVID-19. We assessed inflammatory cells by multiplex immunohistochemistry, cytokines by Luminex xMAP Assay and viral load by real time PCR in autopsy lung tissue of 18 COVID-19 patients. Correlations were considered statistically significant if p<0.05. Macrophages correlated with IL-1beta (r=0.54), IL-10 (r=0.5), IFN-alpha2 (r=0.72), IFN-gamma (r=0.6), CCL20 (r=0.5), TGF-beta1 (r=0.6), TGF-beta2 (r=0.6). CD4+T cells correlated with CCL20 (r=0.6), MDC/CCL2 (r=0.53), CCL17 (r=0.5), IP-10 (r=0.6), CXCL9 (r=0.6). CD8+T cells correlated with IL-1beta (r=0.54), IL-4 (r=0.63), IL-6 (r=0.7), IL-8 (r=0.63), IL-10 (r=0.6), TNF-alpha (r=0.6), IFN-gamma (r=0.74), CCL20 (r=0.7), TGF-beta1 (r=0.7), TGF-beta2 (r=0.56), TGF-beta3 (r=0.54), MDC/CCL2 (r=0.7), CCL17 (r=0.64). Langerin dendritic cells (DC) correlated with symptom onset to death interval (r=0.6), hospitalization length (r=0.65), mechanical ventilation (MV) length (r=0.6), ICU stay (r=0.6), exudative DAD (r=-0.5), viral load (r=-0.6). Myeloid DC correlated with symptom onset to death interval (r=0.8), hospitalization length (r=0.8), MV length (r=0.8), ICU stay (r=0.8), exudative DAD (r=-0.5), viral load (r=-0.7). Viral load correlated with symptom onset to death interval (r=-0.7), hospitalization length (r=-0.8), MV length (r=-0.7), ICU stay (r=-0.8), exudative DAD (r=0.6). There is a complex temporal inflammatory modulation in severe COVID-19.

Predictors of Bradycardia with Dexmedetomidine Use

INTRODUCTION: Although dexmedetomidine is a widely used sedative in the ICU, risk factors for bradycardia associated with dexmedetomidine use are not well characterized. Identifying factors that place a patient at increased risk for bradycardia with dexmedetomidine use may help guide interventions or limit complications associated with the medication's negative chronotropic effects. The aim of this analysis is to determine risk factors for development of bradycardia with dexmedetomidine use. METHOD(S): This single center, retrospective nested casecontrol included adult patients in cardiac and non-cardiac intensive care units with an intravenous dexmedetomidine duration of at least 1 hour. A univariate analysis was used to compare patients with and without bradycardia with dexmedetomidine use, and a predictive model was used to evaluate factors associated with bradycardia. Step-down backward variable selection was used based on Akaike's Information Criterion (AIC) and Bayesian Information Criteria (BIC) to identify the final model. The discriminatory power and absolute predictive ability of the final model was evaluated by the concordance index (c-index), which was internal validated by bootstrapping. Multiple imputation was performed before model selection to fill in missing values in pulse at initiation and Child Pugh Score before modeling. RESULT(S): Of the 1,838 patients receiving dexmedetomidine, 110 patients (6.0%) developed bradycardia within 72 hours of initiation. In patients that experienced bradycardia, 31 (28.1%) required an intervention. The initial full predictive model for bradycardia included age, sex, BMI, COVID19 positive test, hypothermia, pulse at initiation, ICU location (Cardiac vs non-cardiac), Child Pugh Score, use of fentanyl and propofol. Step-down backward variable selection identified 4 predictors in the final model, including COVID positive test, hypothermia, pulse at initiation, and ICU location. The final model achieved a good performance in discriminatory capability (c-index: 0.758, 95%CI 0.713-0.806) using the smallest number of predictors. CONCLUSION(S): Patients with COVID-19, hypothermia, non-cardiac ICU locations and lower pulse at initiation are at increased odds of developing bradycardia. Recognition of risk may be used to guide monitoring or alternative sedation strategies.

Factors associated to risk of death among COVID patients hospitalized in low-intensity care unit: a real-life experience

Background: Second wave of SARS-CoV-2 pandemic showed a devastating impact in term of absolute mortality, higher than observed in the first wave. Objective of the study was to evaluate factors associated with mortality among COVID patients in hospital setting. Materials and Methods: We retrospectively evaluated clinical data, SARS-CoV-2 E and N2 genes expression on nasal swab and outcomes of patients hospitalized for COVID pneumonia in a lowintensity medical care unit during the second wave of pandemic. Results: We evaluated 163 patients (64,4% M, 35,6% F), mean age 69,6±14 years, Decease was observed in 11,7% of cases. A significant higher mortality was present in patients with diabetes (p=0,027;OR 2,91), hematologic diseases (p=0,002;OR 7,4) and cirrhosis (p<0,0001). Remdesivir was the only treatment associated with a lower mortality (p=0,01, OR 0,5). Deceased patients showed a longer duration of symptoms before hospitalization (p=0,032) and lower levels of arterial oxygen tension (pO2) at the admission (p=0,22). Lower admission pO2 levels showed a good accuracy to identify patients who deceased (AUC=0,73, p=0,022), with an optimal cut-off of pO2<45 mmHg (Sns 77%, Spc 81%). An inverse relation between oxygen saturation and gene E (R=-0,28;p=0,009) and N2 (R=-0,36;p=0,003) expression was present. Conclusions: Several factors may stratify the risk of death in patients with COVID pneumonia, including comorbidities, pO2 at the admission and levels of viral replication. A pO2<45 mmHg detected in the emergency department may identify patients with higher risk of death. Remdesivir treatment was associated with a lower mortality.

Tourism in Territorial Economies: A Taxonomy

In this work a territorial analysis is developed, in order to depict the characteristics of the tourism industry and its typical heterogeneity, since tourism is not only locally and seasonally concentrated on the demand side, but is also widely differentiated on the supply side. The empirical research is based on a multivariate analysis applied to an integrated community-level database on touristic supply and demand. Five clusters of municipalities have been identified among the Italian communes. Finally, the analysis of the most recent data on the effects of the covid pandemic on Italian firms, even if not available at the moment on a municipal basis, confirms the extent and the gravity of the crisis. © 2021 Societa Editrice il Mulino. All rights reserved.

Inequality in mortality between Black and White Americans by age, place, and cause, and in comparison to Europe, 1990-2018

Although there is a large gap between Black and White American life expectancies, the gap fell 48.9% between 1990-2018, mainly due to mortality declines among Black Americans. We examine age-specific mortality trends and racial gaps in life expectancy in rich and poor U.S. areas and with reference to six European countries. Inequalities in life expectancy are starker in the U.S. than in Europe. In 1990 White Americans and Europeans in rich areas had similar overall life expectancy, while life expectancy for White Americans in poor areas was lower. But since then even rich White Americans have lost ground relative to Europeans. Meanwhile, the gap in life expectancy between Black Americans and Europeans decreased by 8.3%. Black life expectancy increased more than White life expectancy in all U.S. areas, but improvements in poorer areas had the greatest impact on the racial life expectancy gap. The causes that contributed the most to Black mortality reductions included: Cancer, homicide, HIV, and causes originating in the fetal or infant period. Life expectancy for both Black and White Americans plateaued or slightly declined after 2012, but this stalling was most evident among Black Americans even prior to the COVID-19 pandemic. If improvements had continued at the 1990-2012 rate, the racial gap in life expectancy would have closed by 2036. European life expectancy also stalled after 2014. Still, the comparison with Europe suggests that mortality rates of both Black and White Americans could fall much further across all ages and in both rich and poor areas.

Every document is born "grey" - Some documents can become "open"

As we all know, "grey" doesn't often mean "closed";maybe sometimes it can mean just hard to find. If its sources are open and there are the conditions, the whole document could become an open access one. An example among all is the case of the pre-prints. When you archive a pre-print in a repository you allow the free, open and "grey" pre-print become Open Access to everyone. If the immediately archived "grey" pre-print is open access it can accelerate global knowledge and research advancement. The recent COVID-19 pandemic is making us rethink the way we communicate, search, research and inform;there are some cases of publishers which immediately publish some COVID-19 related articles pre-print;other, instead, are making soon available the accepted manuscript (post-print). Let us concentrate on pre-prints, closer to "grey" literature. An immediate and open pre-print could accelerate research in some fields and could let researchers (and us) know on time if there is a deadlock or not. Some publishers are following this way. By the way, some pre-prints will never become a published article;in any case knowing those pre-prints let people know why that way is an unpassable one or if some other ways to improve research could be passable. So, "grey" sometimes could become open to improve and accelerate research, especially in this uncommon period.

Refractory myasthenic crisis in a patient with refractory Myasthenia gravis and COVID-19

Background and aims: Myasthenia gravis (MG) is an autoimmune, antibody-mediated disease of the neuromuscular junction causing muscle weakness. Due to immunosuppression and possible respiratory/bulbar muscle weakness, MG patients are at risk for developing severe coronavirus disease 2019 (COVID-19). Methods: Case report. Results: A 62years old patient suffered from bulbar onset generalized MG with acetylcholine receptor antibodies since eight months. He survived two prior MC and was nourished via percutaneous enterogastrostomy (PEG) despite symptomatic treatment and immunosuppression with azathioprine and steroids (severity graded according Myasthenia gravis foundation of America score (MGFA) IVb). He presented with fever, cough and severe generalised muscle weakness. Polymerase chain reaction confirmed COVID-19, ventilatory failure prompted mechanical ventilation (MV). Intravenous immunoglobulins (ivIg) and pyridostigmine i.v. were given. Weaning had to be postponed because of respiratory muscle weakness and septicaemia with Enterobacter cloacae, treated with appriopriate antibiotics. Not until removal of PEG sepsis resolved and plasmapheresis (PLEX) was conducted. The patient reached spontaneous breathing via tracheostomy, but still needed nasogastric tube feeding (MGFA V). Because of missing further progress of bulbar muscle function complement inhibition with eculizumab was administered (900mg 1 x weekly for four weeks, thereafter 1200mg every two weeks). After the second dose tracheostomy and nasogastric tubes could be removed, bulbar and generalized weakness resolved on follow-up (MGFA IIa). Conclusion: Our patient experienced MC triggered by COVID-19 and suffered from prolonged sepsis. After failure of standard treatments (IvIg/PLX) eculizumab was given, followed by marked recovery. The role of complement inhibition for treatment of refractory myasthenic crises should be further studied.