Conservative oxygen supplementation during helmet continuous positive airway pressure therapy in patients with COVID-19 and respiratory failure: a pilot study.

Background: Respiratory failure is a severe complication in coronavirus disease 2019 (COVID-19) pneumonia that, in addition to oxygen therapy, may require continuous positive airway pressure (CPAP) support. It has been postulated that COVID-19 lung injury may share some features with those observed in hyperoxic acute lung injury. Thus, a correct target arterial oxygen tension (P aO2 ) during oxygen supplementation may be crucial to protect the lung from further tissue damage. The aims of this study were: 1) to evaluate the effects of conservative oxygen supplementation during helmet CPAP therapy on mortality and intensive care unit (ICU) admission in patients with COVID-19 and respiratory failure, and 2) to evaluate the effect of conservative oxygen supplementation on new-onset organ failure and secondary pulmonary infections. Methods: This was a single-centre, historically controlled study of patients with severe respiratory failure due to COVID-19 pneumonia, receiving either conservative or nonconservative oxygen supplementation during helmet CPAP. A cohort receiving conservative oxygen supplementation was studied prospectively in which oxygen supplementation was administered with a target P aO2 <100 mmHg. Results of this cohort were compared with those of a cohort who had received liberal oxygen supplementation. Results: 71 patients were included in the conservative cohort and 75 in the nonconservative cohort. Mortality rate was lower in the conservative cohort (22.5% versus 62.7%; p<0.001). Rates of ICU admission and new-onset organ failure were lower in the conservative cohort (14.1% versus 37.3%; p=0.001 and 9.9% versus 45.3%; p<0.001, respectively). Conclusions: In patients with COVID-19 and severe respiratory failure, conservative oxygen supplementation during helmet CPAP was associated with improved survival, lower ICU admission rate and less new-onset organ failure.

Age-dependent NK cell dysfunctions in severe COVID-19 patients.

Natural Killer (NK) cells are key innate effectors of antiviral immune response, and their activity changes in ageing and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Here, we investigated the age-related changes of NK cell phenotype and function during SARS-CoV-2 infection, by comparing adult and elderly patients both requiring mechanical ventilation. Adult patients had a reduced number of total NK cells, while elderly showed a peculiar skewing of NK cell subsets towards the CD56lowCD16high and CD56neg phenotypes, expressing activation markers and check-point inhibitory receptors. Although NK cell degranulation ability is significantly compromised in both cohorts, IFN-γ production is impaired only in adult patients in a TGF-ß-dependent manner. This inhibitory effect was associated with a shorter hospitalization time of adult patients suggesting a role for TGF-ß in preventing an excessive NK cell activation and systemic inflammation. Our data highlight an age-dependent role of NK cells in shaping SARS-CoV-2 infection toward a pathophysiological evolution.

False-negative RT-PCR in SARS-CoV-2 disease: experience from an Italian COVID-19 unit.

False-negative cases of #COVID19 are being increasingly reported. Laboratory diagnosis through RT-PCR testing alone lacks adequate sensitivity to be recommended as the only valid criterion to confirm COVID-19 diagnosis. https://bit.ly/2BLFnEe.

Minimal clinically important difference for asthma endpoints: an expert consensus report.

Minimal clinically important difference (MCID) can be defined as the smallest change or difference in an outcome measure that is perceived as beneficial and would lead to a change in the patient's medical management.The aim of the current expert consensus report is to provide a "state-of-the-art" review of the currently available literature evidence about MCID for end-points to monitor asthma control, in order to facilitate optimal disease management and identify unmet needs in the field to guide future research.A series of MCID cut-offs are currently available in literature and validated among populations of asthmatic patients, with most of the evidence focusing on outcomes as patient reported outcomes, lung function and exercise tolerance. On the contrary, only scant and partial data are available for inflammatory biomarkers. These clearly represent the most interesting target for future development in diagnosis and clinical management of asthma, particularly in view of the several biologic drugs in the pipeline, for which regulatory agencies will soon require personalised proof of efficacy and treatment response predictors.