Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused the pandemic Coronavirus Disease 2019 (COVID-19). This virus is highly transmissible among individuals through both droplets and aerosol leading to determine severe pneumonia. Among the various factors that can influence both the onset of disease and the severity of its complications, the microbiome composition has also been investigated. Recent evidence showed the possible relationship between gut, lung, nasopharyngeal, or oral microbiome and COVID-19, but very little is known about it. Therefore, we aimed to verify the relationships between nasopharyngeal microbiome and the development of either COVID-19 or the severity of symptoms. To this purpose, we analyzed, by next generation sequencing, the hypervariable V1-V2-V3 regions of the bacterial 16S rRNA in nasopharyngeal swabs from SARS-CoV-2 infected patients (n=18) and control (CO) individuals (n=12) using Microbiota solution A (Arrow Diagnostics). We found a significant lower abundance of Proteobacteria and Fusobacteria in COVID-19 patients in respect to CO (p=0.003 and p<0.0001, respectively) from the phylum up to the genus (p<0.001). The Fusobacterium periodonticum (FP) resulted as the most significantly reduced species in COVID-19 patients respect to CO. FP is reported as being able to perform the surface sialylation. Noteworthy, some sialic acids residues on the cell surface could work as additional S protein of SARS-CoV-2 receptors. Consequently, SARS-CoV-2 could use sialic acids as receptors to bind to the epithelium of the respiratory tract, promoting its clustering and the disease development. We can therefore speculate that the significant reduction of FP in COVID-19 patients could be directly or indirectly linked to the modulation of sialic acid metabolism. Finally, viral or environmental factors capable of interfering with sialic metabolism could determine a fall in the individual protection from SARS-CoV-2. Further studies are necessary to clarify the precise role of FP in COVID-19.

Introduction: A hypercoagulable condition was described in patients with COVID-19 and proposed as a possible pathogenic mechanism contributing to disease progression and lethality. Aim: We evaluated if in-hospital administration of heparin improved survival in a large cohort of Italian COVID-19 patients. Methods: In a retrospective observational study, 2,574 unselected patients hospitalised in 30 clinical centres in Italy from February 19, 2020 to May 23, 2020 with laboratory-confirmed SARS-CoV-2 infection, were analysed. The primary end-point in a time-to event analysis was in-hospital death, comparing patients who received heparin (low-molecular weight heparin (LMWH) or unfractionated heparin (UFH)) with patients who did not. We used multivariable Cox proportional-hazards regression models with inverse probability for treatment weighting by propensity scores. Results: Out of 2,574 COVID-19 patients, 70.1% received heparin. LMWH was largely the most used formulation (99.5%). Death rates for patients receiving heparin or not were 7.4 and 14.0 per 1,000 person-days, respectively. After adjustment for propensity scores, we found a 40% lower risk of death in patients receiving heparin (HR=0.60; 95%CI: 0.49 to 0.74; E-value=2.04). This association was particularly evident in patients with a higher severity of disease or strong coagulation activation. Conclusions: In-hospital heparin treatment was associated with lower mortality, particularly in severely ill COVID-19 patients and in those with strong coagulation activation. The results from randomised clinical trials are eagerly awaited to provide clear-cut recommendations.

The molecular basis of the wide clinical heterogeneity of Coronavirus disease 2019 (COVID-19) is still unknown. Matrix metalloproteinases (MMPs) may have a role in the lung damage and regeneration that occur in severe patients. We studied serum MMP3 and MMP9 as potential biomarkers of COVID-19 severity, in 108 hospitalized patients with different World Health Organization (WHO) severity stage and in 48 controls. At hospital admission, serum MMP3 was increased in COVID-19 patients with a significant trend along the progression of the WHO stage, while serum levels of MMP9 were significantly increased in COVID-19 patients with no correlation with disease severity. At 1 week from hospitalization, MMP3 was reduced, suggesting an early pathogenic role of the protein in lung inflammation, while MMP9 levels were further increased, indicating a late role of the protein in the inflammatory process, specifically during the repairing phase. Furthermore, serum MMP9 was positively correlated with serum interleukin-6, myeloperoxidase, and circulating neutrophils and monocytes number. In conclusion, serum MMP3 may help to early predict the severity of COVID-19 and both proteins, MMP3 and MMP9, may contribute to define severe COVID-19 patients that may benefit from a targeted therapy on MMPs.

BackgroundThe aim of the study was to compare coronavirus disease 2019 (COVID-19) severity presentation between oncologic and non-oncologic patients and to evaluate the impact of cancer type and stage on COVID-19 course.MethodsWe performed a multicentre, retrospective study involving 13 COVID-19 Units in Campania region from February to May 2020. We defined as severe COVID-19 presentation the cases that required mechanical ventilation and/or admission to Intensive Care Units (ICU) and/or in case of death.ResultsWe enrolled 371 COVID-19 patients, of whom 34 (9.2%) had a history or a diagnosis of cancer (24 solid, 6 onco-hematological). Oncologic patients were older (p<0.001), had more comorbidities (p<0.001) and showed a higher rate of severe COVID-19 presentation (p=0.001) and of death (p<0.001). Compared to 12 patients with non-active cancer and to 337 without cancer, the 17 patients with active cancer had more comorbidities and showed a higher rate of severe COVID-19 and of mortality (all p values <0.001). Compared to the 281 non-severe patients, the 90 subjects with a severe presentation of COVID-19 were older (p<0.01), with more comorbidities (p<0.001) and with a higher rate of cancer (p=0.001). At multivariate analysis, age (OR 1.08, 95% CI: 1.04-1.11) and suffering from cancer in an active stage (OR 5.33, 95% CI: 1.77-16.53) were independently associated with severe COVID-19.ConclusionsSince the higher risk of severe evolution of COVID-19, cancer patients, especially those with an active malignancy, should be candidates for early evaluation of symptoms and early treatment for COVID-19.

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