Natural killer-cell immunoglobulin-like receptors trigger differences in immune response to SARS-CoV-2 infection

Background: The diversity in the clinical course of COVID-19 has been related to differences in innate and adaptative immune response mechanisms. Natural killer (NK) lymphocytes are critical protagonists of human host defense against viral infections. It would seem that reduced circulating levels of these cells have an impact on COVID-19 progression and severity. Their activity is strongly regulated by killer-cell immuno-globulin-like receptors (KIRs) expressed on the NK cell surface. The present study's focus was to investigate the impact of KIRs and their HLA Class I ligands on SARS-CoV-2 infection. Methods: KIR gene frequencies, KIR haplotypes, KIR ligands and combinations of KIRs and their HLA Class I ligands were investigated in 396 Sardinian patients with SARS-CoV-2 infection. Comparisons were made between 2 groups of patients divided according to disease severity: 240 patients were symptomatic or paucisymptomatic (Group A), 156 hospitalized patients had severe disease (Group S). The immunogenetic characteristics of patients were also compared to a population group of 400 individuals from the same geographical areas. Results: Substantial differences were obtained for KIR genes, KIR haplotypes and KIR-HLA ligand combinations when comparing patients of Group S to those of Group A. Patients in Group S had a statistically significant higher frequency of the KIR A/A haplotype compared to patients in Group A [34.6% vs 23.8%, OR = 1.7 (95% CI 1.1-2.6); P = 0.02, Pc = 0.04]. Moreover, the KIR2DS2/HLA C1 combination was poorly represented in the group of patients with severe symptoms compared to those of the asymptomatic-paucisymptomatic group [33.3% vs 50.0%, OR = 0.5 (95% CI 0.3-0.8), P = 0.001, Pc = 0.002]. Multivariate analysis confirmed that, regardless of the sex and age of the patients, the latter genetic variable correlated with a less severe disease course [ORM = 0.4 (95% CI 0.3-0.7), PM = 0.0005, PMC = 0.005]. Conclusions: The KIR2DS2/HLA C1 functional unit resulted to have a strong protective effect against the adverse outcomes of COVID-19. Combined to other well known factors such as advanced age, male sex and concomitant autoimmune diseases, this marker could prove to be highly informative of the disease course and thus enable the timely intervention needed to reduce the mortality associated with the severe forms of SARS-CoV-2 infection. However, larger studies in other populations as well as experimental functional studies will be needed to confirm our findings and further pursue the effect of KIR receptors on NK cell immune-mediated response to SARS-Cov-2 infection

CEFTO-CURE study: CEFTObiprole Clinical Use in Real-lifE - a multi-centre experience in Italy

Background: Ceftobiprole is approved in Europe for treatment of community-acquired pneumonia and non-ventilator-associated hospital-acquired pneumonia (HAP) in adults. Real-world data are limited. Methods: This multi-centre, observational, ambispective investigator-initiated study was undertaken in Italy from January 2018 to December 2019 in order to evaluate the use of ceftobiprole in a real-world setting. Results: Overall, 195 patients from 10 centres were evaluated (68% retrospectively). Male sex was prevalent (n=121, 62%). Median age was 67 [interquartile range (IQR) 53-75] years. Median Charlson Comorbidity Index score was 5 (IQR 3-7). The most common indication was pneumonia (151/195, 77%), especially HAP. Other uses were skin and soft tissue infections (5%), endocarditis (4%) and bone infections (4%). Ceftobiprole was usually an empiric choice (65%), in combination with other drugs (66%) and as second-line therapy (58%). A causative agent was found in 39% of cases. A diagnosis of sepsis was made in 59 cases (30%). Success in the clinically evaluable population (excluding 12 cases due to isolation of pathogens outside ceftobiprole's spectrum of activity) was obtained in 79% of cases, with all-cause mortality of 20%. On multi-level analysis, three predictors were positively associated with clinical success: male gender, pneumonia and detection of causal agent. Sepsis was a negative predictor. Nine factors were independently associated, favourably or unfavourably, with fatal outcome. Conclusions: Ceftobiprole is a safe and effective therapeutic choice, even in a real-world setting. More data are needed to establish its efficacy in patients with sepsis