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Background The goal of this study was to investigate the prevalence and factors associated with persistent viral shedding (PVS) in hospitalized patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Methods This was a prospective observational study including all consecutive adults hospitalized with SARS-CoV-2 infection. When the first nasopharyngeal swab was positive for SARS-CoV-2 RNA (day 0), additional samples were obtained on days + 3, + 5, + 7 and then once every 7 days until virus detection was negative. PVS was defined as the duration of shedding of at least 21 days after diagnosis. The primary endpoint of this study was the prevalence of PVS. Results Data were obtained regarding 121 consecutive hospitalized patients with SARS-CoV-2 infection (median age 66 years, male sex 65.3%). Overall, the prevalence of PVS was 38% (46/121 patients). According to univariate analysis, factors associated with PVS were immunosuppression (6.7% vs 21.7%, p = 0.02), increased interleukin-6 (IL-6) levels (≥ 35 ng/ml) at the time of diagnosis (43.4% vs 67.3%, p = 0.02), time from onset of symptoms to diagnosis (median days 7.0 vs 3.5, p = 0.001), intensive care unit admission (22.7% vs 43.5%, p = 0.02), and need for invasive mechanical ventilation (20.0% vs 41.3%, p = 0.01). The multivariate analysis indicated that immunosuppression, increased IL-6 levels at the time of diagnosis, time from onset of symptoms to diagnosis, and need for mechanical ventilation were independent factors associated with PVS. Conclusions PVS was detected in up to 38% of hospitalized patients with SARS-CoV-2 infection and was strongly associated with immunosuppression, increased IL-6 levels, and the need for mechanical ventilation. Supplementary Information The online version contains supplementary material available at 10.1007/s40121-020-00381-8.

BACKGROUND Increases in cardiac troponin (cTn) in coronavirus disease 2019 (COVID-19) have been associated with worse prognosis. Nonetheless, data about the significance of cTn in elderly subjects with COVID-19 are lacking. METHODS From a registry of consecutive patients with COVID-19 admitted to a hub hospital in Italy from 25/02/2020 to 03/07/2020, we selected those ≥ 60 year-old and with cTnI measured within three days from the molecular diagnosis of SARS-CoV-2 infection. When available, a second cTnI value within 48 h was also extracted. The relationship between increased cTnI and all-cause in-hospital mortality was evaluated by a Cox regression model and restricted cubic spline functions with three knots. RESULTS Of 343 included patients (median age: 75.0 (68.0−83.0) years, 34.7% men), 88 (25.7%) had cTnI above the upper-reference limit (0.046 µg/L). Patients with increased cTnI had more comorbidities, greater impaired respiratory exchange and higher inflammatory markers on admission than those with normal cTnI. Furthermore, they died more (73.9%vs. 37.3%, P < 0.001) over 15 (6−25) days of hospitalization. The association of elevated cTnI with mortality was confirmed by the adjusted Cox regression model (HR = 1.61, 95%CI: 1.06−2.52, P = 0.039) and was linear until 0.3 µg/L, with a subsequent plateau. Of 191 (55.7%) patients with a second cTnI measurement, 49 (25.7%) had an increasing trend, which was not associated with mortality (univariate HR = 1.39, 95%CI: 0.87−2.22, P = 0.265). CONCLUSIONS In elderly COVID-19 patients, an initial increase in cTn is common and predicts a higher risk of death. Serial cTn testing may not confer additional prognostic information.

OBJECTIVES The aim of this study is to develop a Machine Learning (ML) algorithm for an automatic classification of fetal occiput position at transperineal ultrasound (TPU) during the second stage of labor. METHODS Prospective cohort study including singleton term pregnancies (> 37 weeks of gestation) in the second stage of labor, with the fetus in cephalic presentation. Transabdominal ultrasound was preliminarily performed to assess the actual fetal occiput position, which was labeled as occiput anterior (OA) or non-occiput anterior (non-OA). Subsequently, for each case, one sonographic image of the fetal head was acquired on the axial plane using TPU and archived on a cloud for remote analysis. Using the transabdominal sonographic diagnosis as the gold standard, a ML algorithm based on a pattern recognition feed-forward neural network was trained on the transperineal images to discriminate between OA and non-OA cases. In the training phase the model tuned its parameters in order to approximate correctly the training data - i.e., the training dataset - in order to correctly assess the fetal head position, by exploiting geometric, morphological and intensity-based features of the images. In the testing phase, the diagnostic performance of the algorithm was evaluated on unlabeled data, which represented the testing dataset. On this group the ability of the ML algorithm to differentiate the OA from the non-OA fetal positions was assessed in terms of diagnostic accuracy. The F1 -score and Precision-Recall Area Under the Curve (PR-AUC) were also calculated to assess the algorithm's performance. The Cohen's kappa (k) was finally added to evaluate the agreement between the algorithm and the gold standard. RESULTS Over a period of 24 months, 1219 women in the second stage of labor were enrolled. They were classified as OA (n=801 or 65.7%) or non-OA (n=418 or 34.3%) on the basis of transabdominal ultrasound. From both the sub-groups (OA and non-OA), 70% of the patients were randomly assigned to the training dataset (824 patients) while the remaining 30% (395 patients) were used as testing dataset. On the latter group the ML based algorithm yielded a correct classification of the fetal occiput position in 90.6% of cases (357 out of 395), including 224 out of 246 OA (91.0%) and of 133 out of 149 non-OA images (89.3%). Moreover, for the evaluation the algorithm's performance we found a F1 -score=88.7% and PR-AUC=85.4%. The algorithm showed a balanced performance in the recognition of both anterior and non-anterior occiput positions. Eventually, the robustness of the proposed algorithm was confirmed by a high agreement with the gold standard method (k = 0.81; p

The SARS-CoV-2 infection causes severe respiratory involvement (COVID-19) in 5–20% of patients through initial immune derangement, followed by intense cytokine production and vascular leakage. Evidence of immune involvement point to the participation of T, B, and NK cells in the lack of control of virus replication leading to COVID-19. NK cells contribute to early phases of virus control and to the regulation of adaptive responses. The precise mechanism of NK cell dysregulation is poorly understood, with little information on tissue margination or turnover. We investigated these aspects by multiparameter flow cytometry in a cohort of 28 patients hospitalized with early COVID-19. Relevant decreases in CD56brightCD16+/- NK subsets were detected, with a shift of circulating NK cells toward more mature CD56dimCD16+KIR+NKG2A+ and “memory” KIR+CD57+CD85j+ cells with increased inhibitory NKG2A and KIR molecules. Impaired cytotoxicity and IFN-γ production were associated with conserved expression of natural cytotoxicity receptors and perforin. Moreover, intense NK cell activation with increased HLA-DR and CD69 expression was associated with the circulation of CD69+CD103+ CXCR6+ tissue-resident NK cells and of CD34+DNAM-1brightCXCR4+ inflammatory precursors to mature functional NK cells. Severe disease trajectories were directly associated with the proportion of CD34+DNAM-1brightCXCR4+ precursors and inversely associated with the proportion of NKG2D+ and of CD103+ NK cells. Intense NK cell activation and trafficking to and from tissues occurs early in COVID-19, and is associated with subsequent disease progression, providing an insight into the mechanism of clinical deterioration. Strategies to positively manipulate tissue-resident NK cell responses may provide advantages to future therapeutic and vaccine approaches., Author summary This is a detailed study of activating and inhibitory receptors in NK cells of COVID-19 patients when first admitted to the hospital for respiratory insufficiency. NK cells are known to be the first line of defense against invading viruses, and regulate downstream B and T cell responses, including antibody production. We observed intense NK cell activation with decreased functional activity, as well as intense circulation of putative tissue resident CD69+CD103+CXCR6+ NK cells, with a related surge in inflammatory CD34+ precursors from the bone marrow. The findings suggest that there is unprecedented trafficking of NK cells from peripheral tissues, their increased death with recruitment of emergency precursors from the bone marrow, and a relationship with the subsequent course of the disease of the patients. This in turn suggests possible areas of treatment and prevention.