Detailed stratified GWAS analysis for severe COVID-19 in four European populations.

Given the highly variable clinical phenotype of Coronavirus disease 2019 (COVID-19), a deeper analysis of the host genetic contribution to severe COVID-19 is important to improve our understanding of underlying disease mechanisms. Here, we describe an extended genome-wide association meta-analysis of a well-characterized cohort of 3255 COVID-19 patients with respiratory failure and 12 488 population controls from Italy, Spain, Norway and Germany/Austria, including stratified analyses based on age, sex and disease severity, as well as targeted analyses of chromosome Y haplotypes, the human leukocyte antigen region and the SARS-CoV-2 peptidome. By inversion imputation, we traced a reported association at 17q21.31 to a ~0.9-Mb inversion polymorphism that creates two highly differentiated haplotypes and characterized the potential effects of the inversion in detail. Our data, together with the 5th release of summary statistics from the COVID-19 Host Genetics Initiative including non-Caucasian individuals, also identified a new locus at 19q13.33, including NAPSA, a gene which is expressed primarily in alveolar cells responsible for gas exchange in the lung.

Tracking the immune response profiles elicited by the BNT162b2 vaccine in COVID-19 unexperienced and experienced individuals.

Multiple vaccines have been approved to control COVID-19 pandemic, with Pfizer/BioNTech (BNT162b2) being widely used. We conducted a longitudinal analysis of the immune response elicited after three doses of the BNT162b2 vaccine in individuals who have previously experienced SARS-CoV-2 infection and in unexperienced ones. We conducted immunological analyses and single-cell transcriptomics of circulating T and B lymphocytes, combined to CITE-seq or LIBRA-seq, and VDJ-seq. We found that antibody levels against SARS-CoV-2 Spike, NTD and RBD from wild-type, delta and omicron VoCs show comparable dynamics in both vaccination groups, with a peak after the second dose, a decline after six months and a restoration after the booster dose. The antibody neutralization activity was maintained, with lower titers against the omicron variant. Spike-specific memory B cell response was sustained over the vaccination schedule. Clonal analysis revealed that Spike-specific B cells were polyclonal, with a partial clone conservation from natural infection to vaccination. Spike-specific T cell responses were oriented towards effector and effector memory phenotypes, with similar trends in unexperienced and experienced individuals. The CD8 T cell compartment showed a higher clonal expansion and persistence than CD4 T cells. The first two vaccinations doses tended to induce new clones rather than promoting expansion of pre-existing clones. However, we identified a fraction of Spike-specific CD8 T cell clones persisting from natural infection that were boosted by vaccination and clones specifically induced by vaccination. Collectively, our observations revealed a moderate effect of the second dose in enhancing the immune responses elicited after the first vaccination. Differently, we found that a third dose was necessary to restore comparable levels of neutralizing antibodies and Spike-specific T and B cell responses in individuals who experienced a natural SARS-CoV-2 infection.

Long-term outcomes of bictegravir/emtricitabine/tenofovir alafenamide as first-line therapy and as switch strategy in virologically suppressed persons with HIV: data from the ICONA cohort.

OBJECTIVES: To assess the effectiveness of bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) among people poorly represented in clinical trials and potentially at higher risk of suboptimal response to ART. METHODS: Observational cohort study on persons with HIV (PWH) enrolled in ICONA who started BIC/FTC/TAF as initial therapy or as switching regimen while virologically suppressed. Primary endpoint was time to treatment failure (TF): new AIDS/death or virological failure (VF) or discontinuation for toxicity/failure. Secondary endpoints were time to treatment discontinuation for toxicity (TDT) and to VF. Groups of interest were those aged >50 years, female sex, and advanced HIV disease at first ART start. Probability of the events overall and according to groups and adjusted HR for every endpoint were calculated by Kaplan-Meier curves and Cox regression models. RESULTS: Nine hundred and thirty-three ART-naive and 1655 ART-experienced PWH initiated BIC/FTC/TAF. Over a median follow-up of 69.8 weeks, 89 (9.6%) PWH at their first regimen experienced TF. PWH aged >50 years had 1.83-fold (95% CI: 1.19-2.83) higher risk of TF; PWH with advanced HIV disease had 2.21-fold (95% CI: 1.53-3.82) higher risk; there were no differences in TF according to sex.Over a median follow-up of 146.3 weeks, 109 (6.6%) out of 1655 switching PWH experienced TF; no differences were found in the risk of TF, TDT and VF according to groups of interest. CONCLUSIONS: Overall, BIC/FTC/TAF is well tolerated and virologically effective in the real-world scenario for ART-naive and -experienced PWH. Older ART-naive PWH and those with advanced HIV disease may respond less well as the burden of diseases might compromise treatment efficacy.

Long-term dynamics of natural killer cells in response to SARS-CoV-2 vaccination: Persistently enhanced activity postvaccination.

Natural Killer (NK) cells play a significant role in the early defense against virus infections and cancer. Recent studies have demonstrated the involvement of NK cells in both the induction and effector phases of vaccine-induced immunity in various contexts. However, their role in shaping immune responses following SARS-CoV-2 vaccination remains poorly understood. To address this matter, we conducted a comprehensive analysis of NK cell phenotype and function in SARS-CoV-2 unexposed individuals who received the BNT162b2 vaccine. We employed a longitudinal study design and utilized a panel of 53 15-mer overlapping peptides covering the receptor binding domain (RBD) of the SARS-CoV-2 Spike protein to assess NK cell function at 0 and 20 days following the first vaccine, and 30 and 240 days following booster. Additionally, we evaluated the levels of total IgG anti-Spike antibodies and their potential neutralizing ability. Our findings revealed an increased NK cell activity upon re-exposure to RBD when combined with IL12 and IL18 several months after booster. Concurrently, we observed that the frequencies of NKG2A + NK cells declined over the course of the follow-up period, while NKG2C increased only in CMV positive subjects. The finding that NK cell functions are inducible 9 months after vaccination upon re-exposure to RBD and cytokines, sheds light on the role of NK cells in contributing to SARS-CoV-2 vaccine-induced immune protection and pave the way to further studies in the field.

Carbapenem or new ß-lactam-ß-lactamase inhibitors? An Italian survey supported by SITA, SIMIT and SIAARTI to identify the factors affecting empiric antimicrobial therapy choice in real-life clinical practice.

While a tailored antibiotic treatment plan is often straightforward, what we often observe in daily clinical practice is a highly variable approach when defining empirical therapy. Specifically, a debate exists on preference to spare the new ß-lactams and ß-lactamase inhibitors (BL-BLIs) or to apply a carbapenem-sparing strategy first. To investigate, we designed a web survey aimed at investigating the variables considered relevant to empirically choosing one antibiotic over the other. Submitted to Italian infectious diseases and intensive care physicians through the support of Società Italiana di Malattie Infettive e Tropicali (SIMIT), Società Italiana di Terapia Antinfettiva (SITA) and Società Italiana Anestesia, Analgesia, Rianimazione e Terapia Intensiva (SIAARTI). We found that demographic characteristics were irrelevant when deciding for empirical therapy. Clinical and anamnestic data were most meaningful. Significantly considered were underlying comorbidities and previous exposure to antimicrobial treatments. History of third-generation cephalosporin-resistant, carbapenem-resistant and/or metallo-ß-lactamase-producing Enterobacterales rectal colonisation and/or infection were considered the most relevant by most physicians. Unexpectedly, clinicians considered less the source of infection. These results prompt the need of straightforward methods to retrieve medical histories and the magnitude of rectal colonisation data, often not routinely obtained.

Adverse events during intravenous fosfomycin therapy in a real-life scenario. Risk factors and the potential role of therapeutic drug monitoring.

BACKGROUND: Intravenous fosfomycin (IVFOF) is gaining interest in severe infections. Its use may be limited by adverse events (AEs). Little experience exists on IVFOF therapeutic drug monitoring (TDM) in real-life setting. PATIENTS AND METHODS: Retrospective study of patients receiving IVFOF for > 48 h at Policlinico Hospital (Milan, Italy) from 01/01/2019 to 01/01/2023. AEs associated to IVFOF graded CTCAE ≥ II were considered. Demographic and clinical risk factors for IVFOF-related AEs were analysed with simple and multivariable regression models. The determination of IVFOF TDM was made by a rapid ultraperformance liquid chromatography mass spectrometry method (LC-MS/MS) on plasma samples. The performance of TDM (trough levels (Cmin) in intermittent infusion, steady state levels (Css) in continuous infusion) in predicting AEs ≤ 5 days after its assessment was evaluated. RESULTS: Two hundred and twenty-four patients were included. At IVFOF initiation, 81/224 (36.2%) patients were in ICU and 35/224 (15.7%) had septic shock. The most frequent infection site was the low respiratory tract (124/224, 55.4%). Ninety-five patients (42.4%) experienced ≥ 1AEs, with median time of 4.0 (2.0-7.0) days from IVFOF initiation. Hypernatremia was the most frequent AE (53/224, 23.7%). Therapy discontinuation due to AEs occurred in 38/224 (17.0%). ICU setting, low respiratory tract infections and septic shock resulted associated with AEs (RRadjusted 1.59 (95%CI:1.09-2.31), 1.46 (95%CI:1.03-2.07) and 1.73 (95%CI:1.27-2.37), respectively), while IVFOF daily dose did not. Of the 68 patients undergone IVFOF TDM, TDM values predicted overall AEs and hypernatremia with AUROC of 0.65 (95%CI:0.44-0.86) and 0.91 (95%CI:0.79-1.0) respectively for Cmin, 0.67 (95%CI:0.39-0.95) and 0.76 (95%CI:0.52-1.0) respectively for Css. CONCLUSIONS: We provided real world data on the use of IVFOF-based regimens and associated AEs. IVFOF TDM deserves further research as it may represent a valid tool to predict AEs. KEY POINTS: Real world data on intravenous fosfomycin for severe bacterial infections. AEs occurred in over 40% (therapy discontinuation in 17%) and were related to baseline clinical severity but not to fosfomycin dose. TDM showed promising results in predicting AEs.

New Antibiotics Against Multidrug-Resistant Gram-Negative Bacteria in Liver Transplantation: Clinical Perspectives, Toxicity, and PK/PD Properties.

Antimicrobial resistance is a growing global health problem, and it is especially relevant among liver transplant recipients where infections, particularly when caused by microorganisms with a difficult-to-treat profile, are a significant cause of morbidity and mortality. We provide here a complete dissection of the antibiotics active against multidrug-resistant Gram-negative bacteria approved over the last years, focusing on their activity spectrum, toxicity profile and PK/PD properties, including therapeutic drug monitoring, in the setting of liver transplantation. Specifically, the following drugs are presented: ceftolozane/tazobactam, ceftazidime/avibactam, meropenem/vaborbactam, imipenem/relebactam, cefiderocol, and eravacycline. Overall, studies on the safety and optimal employment of these drugs in liver transplant recipients are limited and especially needed. Nevertheless, these pharmaceuticals have undeniably enhanced therapeutic options for infected liver transplant recipients.

Multidrug-Resistant Bacterial Colonization and Infections in Large Retrospective Cohort of Mechanically Ventilated COVID-19 Patients1.

Few data are available on incidence of multidrug-resistant organism (MDRO) colonization and infections in mechanically ventilated patients, particularly during the COVID-19 pandemic. We retrospectively evaluated all patients admitted to the COVID-19 intensive care unit (ICU) of Hub Hospital in Milan, Italy, during October 2020‒May 2021. Microbiologic surveillance was standardized with active screening at admission and weekly during ICU stay. Of 435 patients, 88 (20.2%) had MDROs isolated ≤48 h after admission. Of the remaining patients, MDRO colonization was diagnosed in 173 (51.2%), MDRO infections in 95 (28.1%), and non-MDRO infections in 212 (62.7%). Non-MDRO infections occurred earlier than MDRO infections (6 days vs. 10 days; p<0.001). Previous exposure to antimicrobial drugs within the ICU was higher in MDRO patients than in non-MDRO patients (116/197 [58.9%] vs. 18/140 [12.9%]; p<0.001). Our findings might serve as warnings for future respiratory viral pandemics and call for increased measures of antimicrobial stewardship and infection control.

Genomewide Association Study of Severe Covid-19 with Respiratory Failure.

BACKGROUND: There is considerable variation in disease behavior among patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (Covid-19). Genomewide association analysis may allow for the identification of potential genetic factors involved in the development of Covid-19. METHODS: We conducted a genomewide association study involving 1980 patients with Covid-19 and severe disease (defined as respiratory failure) at seven hospitals in the Italian and Spanish epicenters of the SARS-CoV-2 pandemic in Europe. After quality control and the exclusion of population outliers, 835 patients and 1255 control participants from Italy and 775 patients and 950 control participants from Spain were included in the final analysis. In total, we analyzed 8,582,968 single-nucleotide polymorphisms and conducted a meta-analysis of the two case-control panels. RESULTS: We detected cross-replicating associations with rs11385942 at locus 3p21.31 and with rs657152 at locus 9q34.2, which were significant at the genomewide level (P<5×10-8) in the meta-analysis of the two case-control panels (odds ratio, 1.77; 95% confidence interval [CI], 1.48 to 2.11; P = 1.15×10-10; and odds ratio, 1.32; 95% CI, 1.20 to 1.47; P = 4.95×10-8, respectively). At locus 3p21.31, the association signal spanned the genes SLC6A20, LZTFL1, CCR9, FYCO1, CXCR6 and XCR1. The association signal at locus 9q34.2 coincided with the ABO blood group locus; in this cohort, a blood-group-specific analysis showed a higher risk in blood group A than in other blood groups (odds ratio, 1.45; 95% CI, 1.20 to 1.75; P = 1.48×10-4) and a protective effect in blood group O as compared with other blood groups (odds ratio, 0.65; 95% CI, 0.53 to 0.79; P = 1.06×10-5). CONCLUSIONS: We identified a 3p21.31 gene cluster as a genetic susceptibility locus in patients with Covid-19 with respiratory failure and confirmed a potential involvement of the ABO blood-group system. (Funded by Stein Erik Hagen and others.).

Heterogeneity of Latency Establishment in the Different Human CD4+ T Cell Subsets Stimulated with IL-15.

HIV integrates into the host genome, creating a viral reservoir of latently infected cells that persists despite effective antiretroviral treatment. CD4-positive (CD4+) T cells are the main contributors to the HIV reservoir. CD4+ T cells are a heterogeneous population, and the mechanisms of latency establishment in the different subsets, as well as their contribution to the reservoir, are still unclear. In this study, we analyzed HIV latency establishment in different CD4+ T cell subsets stimulated with interleukin 15 (IL-15), a cytokine that increases both susceptibility to infection and reactivation from latency. Using a dual-reporter virus that allows discrimination between latent and productive infection at the single-cell level, we found that IL-15-treated primary human CD4+ T naive and CD4+ T stem cell memory (TSCM) cells are less susceptible to HIV infection than CD4+ central memory (TCM), effector memory (TEM), and transitional memory (TTM) cells but are also more likely to harbor transcriptionally silent provirus. The propensity of these subsets to harbor latent provirus compared to the more differentiated memory subsets was independent of differential expression of pTEFb components. Microscopy analysis of NF-κB suggested that CD4+ T naive cells express smaller amounts of nuclear NF-κB than the other subsets, partially explaining the inefficient long terminal repeat (LTR)-driven transcription. On the other hand, CD4+ TSCM cells display similar levels of nuclear NF-κB to CD4+ TCM, CD4+ TEM, and CD4+ TTM cells, indicating the availability of transcription initiation and elongation factors is not solely responsible for the inefficient HIV gene expression in the CD4+ TSCM subset. IMPORTANCE The formation of a latent reservoir is the main barrier to HIV cure. Here, we investigated how HIV latency is established in different CD4+ T cell subsets in the presence of IL-15, a cytokine that has been shown to efficiently induce latency reversal. We observed that, even in the presence of IL-15, the less differentiated subsets display lower levels of productive HIV infection than the more differentiated subsets. These differences were not related to different expression of pTEFb, and modest differences in NF-κB were observed for CD4+ T naive cells only, implying the involvement of other mechanisms. Understanding the molecular basis of latency establishment in different CD4+ T cell subsets might be important for tailoring specific strategies to reactivate HIV transcription in all the CD4+ T subsets that compose the latent reservoir.

HIV-DNA decrease during treatment in primary HIV-1 infection with three different drug regimens: Italian Network of Acute HIV Infection (INACTION) clinical trial.

As the introduction of antiretroviral therapy (ART) during primary HIV-1 infection (PHI) could restrict the establishment of HIV reservoirs, we aimed to assess the effect of three different ART regimens on HIV-DNA load in people living with HIV (PLWH), who started ART in PHI. Randomized, open-label, multicentric study, including subjects in PHI (defined as an incomplete HIV-1 Western blot and detectable plasma HIV-RNA) in the Italian Network of Acute HIV Infection cohort. Participants were randomly assigned (10:10:8) to a fixed-dose combination of tenofovir alafenamide fumarate (TAF) 10 mg plus emtricitabine (FTC) 200 mg, darunavir 800 mg, and cobicistat 150 mg once daily (group A), or TAF 25 mg plus FTC 200 mg, dolutegravir 50 mg once daily (group B), or an intensified four-drug regimen (TAF 10 mg plus FTC 200 mg, dolutegravir 50 mg, darunavir 800 mg, and cobicistat 150 mg once daily) (group C). The primary endpoint was the decrease of HIV-DNA copies/106 peripheral blood mononuclear cells (PBMCs) at weeks (W) 12 and 48. Secondary endpoints were increased in CD4+ cells and in CD4+/CD8+ ratio and percentage of PLWH reaching undetectable HIV-RNA. HIV-DNA was quantified by Droplet Digital PCR (Biorad QX100) and normalized to RPP30 reference gene. This study was registered in ClinicalTrials.gov (number NCT04225325). Among 78 participants enrolled, 30 were randomized to group 1, 28 to group 2, and 20 to group 3. At baseline, median CD4+ count was 658/µL (476-790), HIV-RNA 5.37 (4.38, 6.12) log10 copies/mL, without statistical difference in their change among groups at weeks 12 and 48 (p = 0.432 and 0.234, respectively). The trial was prematurely discontinued for slow accrual and for COVID-19 pandemic-associated restrictions. In the per-protocol analysis, PLWH (n = 72) with undetectable viral load was 54.3% at W12 and 86.4% at W48. Interestingly, the CD4/CD8 ratio progressively increased over time, up to normalization in almost half of the cohort by week 48, despite a deflection in group 3; no difference was observed by the Fiebig stage (I-III vs. IV-VI). HIV-DNA decreased from 4.46 (4.08, 4.81) log10 copies/106 PBMCs to 4.22 (3.79, 4.49) at week 12, and 3.87 (3.46, 4.34) at week 48, without difference among groups. At multivariable analysis, HIV-DNA delta at W48 was associated only with the increase of CD4+ count by 100 cells/mm3 but not with the Fiebig stage, the CD4+/CD8+ ratio, and treatment arm, despite a higher decrease in group 3. Six adverse events were recorded during our study, which did not cause any withdrawal from the study. We observed a decrease in HIV-DNA from baseline to W48 in PLWH treated during PHI, associated with an increase in CD4+ count, unrelated to the treatment arm.

Non-B subtypes account for a large proportion of clustered primary HIV-1 infections in Italy.

OBJECTIVES AND DESIGN: Using pol sequences obtained for routine resistance testing, we characterised the molecular patterns of HIV-1 transmission and factors associated with being part of a transmission cluster among individuals who in 2008-2014 presented with primary HIV-1 infection (PHI) at 11 urban centres across Italy. METHODS: Pol sequences were obtained by Sanger sequencing. Transmission clusters were identified by phylogenetic analysis (maximum likelihood method, confirmed by Bayesian analysis). Multivariable logistic regression explored factors associated with a participant being part of a transmission cluster. RESULTS: The PHI cohort comprised 186 participants (159/186, 85.5% males) with median age 44 years, median CD4 count 464 cells/mm3 and median plasma HIV-1 RNA 5.6 log10 copies/mL. Drug resistance associated mutations were found in 16/186 (8.6%). A diversity of non-B subtypes accounted for 60/186 (32.3%) of all infections. A total of 17 transmission clusters were identified, including 44/186 (23.7%) participants. Each cluster comprised 2-6 sequences. Non-B subtypes accounted for seven clusters and 22/44 (50%) of clustered sequences. In multivariable logistic regression analysis, factors associated with being part of a transmission cluster comprised harbouring a non-B subtype (adjusted OR (adjOR) 2.28; 95% CI 1.03 to 5.05; p=0.04) and showing a lower plasma HIV-1 RNA (adjOR 0.80, 95% CI 0.64 to 0.99; p=0.04). CONCLUSIONS: There was a large contribution of diverse non-B subtypes to transmission clusters among people presenting with acute or recent HIV-1 infection in this cohort, illustrating the evolving dynamics of the HIV-1 epidemic in Italy, where subtype B previously dominated.

Treatable traits and challenges in the clinical management of non-tuberculous mycobacteria lung disease in people with cystic fibrosis.

INTRODUCTION: Over the last ten years an increasing prevalence and incidence of non-tuberculous mycobacteria (NTM) has been reported among patients with cystic fibrosis (CF) Viviani (J Cyst Fibros, 15(5):619-623, 2016). NTM pulmonary disease has been associated with negative clinical outcomes and often requires pharmacological treatment. Although specific guidelines help clinicians in the process of diagnosis and clinical management, the focus on the multidimensional assessment of concomitant problems is still scarce. MAIN BODY: This review aims to identify the treatable traits of NTM pulmonary disease in people with CF and discuss the importance of a multidisciplinary approach in order to detect and manage all the clinical and behavioral aspects of the disease. The multidisciplinary complexity of NTM pulmonary disease in CF requires careful management of respiratory and extra-respiratory, including control of comorbidities, drug interactions and behavioral factors as adherence to therapies. CONCLUSIONS: The treatable trait strategy can help to optimize clinical management through systematic assessment of all the aspects of the disease, providing a holistic treatment for such a multi-systemic and complex condition.

Pillars of long-term antiretroviral therapy success.

BACKGROUND: Meeting the challenge of antiretroviral therapy (ART) whose efficacy can last a lifetime requires continuous updating of the virological, pharmacological, and quality of life outcomes to be pursued and a continuous review of literature data on the efficacy and tolerability of new drugs and therapeutic strategies. METHODS: With the aim of identifying open questions and answers about the current controversies in modern ART, we adapted the Design Thinking methodology to the needs of the design phase of a scientific article, involving a team of experts in HIV care. RESULTS: Five main pillars of treatment success were discussed: sustained virologic suppression over time; immunological recovery; pharmacological attributes; long-term tolerability and safety of ART; and people's satisfaction and quality of life. The definition of the outcomes to be achieved in each thematic area and the tools to achieve them were reviewed and discussed. CONCLUSIONS: Long-term treatment success should be intended as a combination of HIV-RNA suppression, immune recovery, and high quality of life. To achieve this, the regimen should be well-tolerated, with high potency, genetic barrier, and forgiveness, and should be tailored by a person-centered perspective, based on individual needs, preferences, and therapeutic history.

Non-tuberculous mycobacteria lung disease due to Mycobacterium chimaera in a 67-year-old man treated with immune checkpoint inhibitors for lung adenocarcinoma: infection due to dysregulated immunity?

Immune checkpoint inhibitors (ICIs) are drugs growingly employed in cancer immunotherapy which have significantly improved the prognosis of several tumours. ICIs act by restoring the "exhausted" immune system and increasing the number of T cells active against pathogens losing tolerogenic signalling, which has been linked to an increased risk of infectious events. We present the case of a 67-year-old man with locally advanced lung adenocarcinoma treated with the anti-PD-L1 durvalumab. Three months after immunotherapy started, an apparent radiological progression was found with elements suggesting a parenchymal superinfection associated with weight loss, asthenia, and sputum emission. A bronchoalveolar lavage resulted positive for Mycobacterium chimaera, and treatment with amikacin iv (for eight weeks) and daily azithromycin, ethambutol, and rifampicin was started. Thirteen months after treatment started, the patient is alive with a stable lung condition. The case highlights the risk of non-tuberculous mycobacteria lung disease (NTM-LD) in patients receiving ICIs treatment. We hypothesise that durvalumab induced an exaggerated immune response toward the mycobacteria, leading to immunopathology and overt clinical manifestations. Clinicians should be aware of this possibility in patients receiving ICIs developing new signs/symptoms related to the respiratory tract, especially in countries with a high prevalence of NTM-LD.

Perfusion fluid-related infections in liver transplant recipients: A 5-year, single-center, retrospective study.

BACKGROUND: Perfusion fluid (PRF) is employed in liver transplantation (LTx) to maintain graft viability. Still, it represents a new potential way of infection transmission in LTx recipients (LTRs). Currently, no systematic research has investigated this topic. METHODS: Five-year single-center retrospective study conducted on LTRs from January 2017 to December 2021. We analyzed the incidence of positive PRF culture (PRF+) and perfusion fluid-related infections (PRF-RI) and their associated factors. We also assessed 1-year mortality, both overall and infection-related. RESULTS: Overall, 234 LTx were included. PRF+ were found in 31/234 (13.2%) LTx for a total of 37 isolates, with >1 isolate identified in 5 (2.1%) cases. High-risk microorganisms (Enterobacterales 13/37, Enterococcus spp. 4/37, S. aureus 3/37, P. aeruginosa 2/37) were isolated in 25/37 (67.6%) LTRs, the remaining being coagulase-negative staphylococci (12/37, 32.4%). Antimicrobial prophylaxis was administered to all LTRs, always active against the isolate even if suboptimal in 19 cases (61.3%). PRF-RI developed in 4/234 LTx (1.7%), and prophylaxis was considered suboptimal in 2/4 of them. The isolation of >1 microorganism in PRF culture was associated with an increased risk of developing PRF-RI (OR 37.5 [95%CI 2.6-548.4], p = .01). PRF-RI were associated with longer ICU stays (p = .005) and higher 1-year mortality, both overall and related to infections (p = .001). CONCLUSION: Despite PRF+ being infrequent, only a minority of patients develops PRF-RI. Nonetheless, once occurred, PRF-RI seems to increase morbidity and mortality rates.

Validation of the INCREMENT-SOT-CPE score in a large cohort of liver transplant recipients with carbapenem-resistant Enterobacterales infection.

BACKGROUND: Management of infections due to carbapenemase-resistant Enterobacterales (CRE) in solid organ transplant (SOT) recipients remains a difficult challenge. The INCREMENT-SOT-CPE score has been specifically developed from SOT recipients to stratify mortality risk, but an external validation is lacking. METHODS: Multicenter retrospective cohort study of liver transplant (LT) recipients colonized with CRE infection who developed infection after transplant over 7-year period. Primary endpoint was all-cause 30-day mortality from infection onset. A comparison between INCREMENT-SOT-CPE and other selected scores was performed. A two-level mixed effects logistic regression model with random effects for the center was fitted. Performance characteristics at optimal cut-point were calculated. Multivariable Cox regression analysis of risk factors for all-cause 30-day mortality was carried out. RESULTS: Overall, 250 CRE carriers developed infection after LT and were analyzed. The median age was 55 years (interquartile range [IQR]: 46-62) and 157 were males (62.8%). All-cause 30-day mortality was 35.6%. A sequential organ failure assessment (SOFA) score ≥ 11 showed a sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of 69.7%, 76.4%, 62.0%, 82.0%, and 74.0%, respectively. An INCREMENT-SOT-CPE ≥ 11 reported a sensitivity, specificity, PPV, NPV, and accuracy of 73.0%, 62.1%, 51.6%, 80.6% and 66.0%, respectively. At multivariable analysis acute renal failure, prolonged mechanical ventilation, INCREMENT-SOT-CPE score ≥ 11 and SOFA score ≥ 11 were independently associated with all-cause 30-day mortality, while a tigecycline-based targeted regimen was found to be protective. CONCLUSIONS: Both INCREMENT-SOT-CPE ≥ 11 and SOFA ≥ 11 were identified as strong predictors of all-cause 30-day mortality in a large cohort of CRE carriers developing infection after LT.

Incidence, microbiological and immunological characteristics of ventilator-associated pneumonia assessed by bronchoalveolar lavage and endotracheal aspirate in a prospective cohort of COVID-19 patients: CoV-AP study.

BACKGROUND: No univocal recommendation exists for microbiological diagnosis of ventilator-associated pneumonia (VAP). Sampling of either proximal or distal respiratory tract likely impacts on the broad range of VAP incidence between cohorts. Immune biomarkers to rule-in/rule-out VAP diagnosis, although promising, have not yet been validated. COVID-19-induced ARDS made VAP recognition even more challenging, often leading to overdiagnosis and overtreatment. We evaluated the impact of different respiratory samples and laboratory techniques on VAP incidence and microbiological findings in COVID-19 patients. METHODS: Prospective single-centre cohort study conducted among COVID-19 mechanically ventilated patients in Policlinico Hospital (Milan, Italy) from January 2021 to May 2022. Microbiological confirmation of suspected VAP (sVAP) was based on concomitant endotracheal aspirates (ETA) and bronchoalveolar lavage (BAL). Conventional and fast microbiology (FILMARRAY® Pneumonia Panel plus, BALFAPPP) as well as immunological markers (immune cells and inflammatory cytokines) was analysed. RESULTS: Seventy-nine patients were included. Exposure to antibiotics and steroid therapy before ICU admission occurred in 51/79 (64.6%) and 60/79 (65.9%) patients, respectively. Median duration of MV at VAP suspicion was 6 (5-9) days. Incidence rate of microbiologically confirmed VAP was 33.1 (95% CI 22.1-44.0) and 20.1 (95% CI 12.5-27.7) according to ETA and BAL, respectively. Concordance between ETA and BAL was observed in 35/49 (71.4%) cases, concordance between BALFAPPP and BAL in 39/49 (79.6%) cases. With BAL as reference standard, ETA showed 88.9% (95% CI 70.8-97.7) sensitivity and 50.0% (95% CI 28.2-71.8) specificity (Cohen's Kappa 0.40, 95% CI 0.16-0.65). BALFAPPP showed 95.0% (95% CI 75.1-99.9) sensitivity and 69% (95% CI 49.2-84.7) specificity (Cohen's Kappa 0.60, 95% CI 0.39-0.81). BAL IL-1ß differed significantly between VAP (135 (IQR 11-450) pg/ml) and no-VAP (10 (IQR 2.9-105) pg/ml) patients (P = 0.03). CONCLUSIONS: In COVID-19 ICU patients, differences in microbial sampling at VAP suspicion could lead to high variability in VAP incidence and microbiological findings. Concordance between ETA and BAL was mainly limited by over 20% of ETA positive and BAL negative samples, while BALFAPPP showed high sensitivity but limited specificity when evaluating in-panel targets only. These factors should be considered when comparing results of cohorts with different sampling. BAL IL-1ß showed potential in discriminating microbiologically confirmed VAP. CLINICAL TRIAL REGISTRATION: NCT04766983, registered on February 23, 2021.

Air pollution exposure, SARS-CoV-2 infection, and immune response in a cohort of healthcare workers of a large university hospital in Milan, Italy.

Several studies have examined the possible relationship between air pollutants and the risk of COVID-19 but most returned controversial findings. We tried to assess the association between (short- and long-term) exposure to particulate and gaseous pollutants, SARS-CoV-2 infections, and immune response in a population of healthcare workers (HCWs) with well-characterized individual data. We collected occupational and clinical characteristics of all HCWs who performed a nasopharyngeal swab (NPS) for detecting SARS-CoV-2 at the Policlinico Hospital in Milan (Lombardy, Italy) between February 24, 2020 (day after first documented case of COVID-19 in our hospital) and December 26, 2020 (day before start of the vaccination campaign). Each subject was assigned daily average levels of particulate matter ≤10 µm (PM10), nitrogen dioxide (NO2), and ozone (O3) retrieved from the air quality monitoring station closest to his/her residential address. Air pollution data were treated as time-dependent variables, generating person-days at risk. Multivariate Poisson regression models were fit to evaluate the rate of positive NPS and to assess the association between air pollution and antibody titer among NPS-positive HCWs. Among 3712 included HCWs, 635 (17.1%) had at least one positive NPS. A 10 µg/m3 increase in NO2 average concentration in the four days preceding NPS was associated with a higher risk of testing positive [Incidence Rate Ratio (IRR) = 1.08, 95% confidence interval (CI): 1.01; 1.16)]. When considering a 1 µg/m3 increase in 2019 annual NO2 average, we observed a higher risk of infection (IRR: 1.02, 95%CI: 1.00; 1.03) and an increased antibody titer (+2.4%, 95%CI: 1.1; 3.6%). Findings on PM10 and O3 were less consistent and, differently from NO2, were not confirmed in multipollutant models. Our study increases the body of evidence suggesting an active role of air pollution exposure on SARS-CoV-2 infection and confirms the importance of implementing pollution reduction policies to improve public health.

Plasma Proteomic Variables Related to COVID-19 Severity: An Untargeted nLC-MS/MS Investigation.

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection leads to a wide range of clinical manifestations and determines the need for personalized and precision medicine. To better understand the biological determinants of this heterogeneity, we explored the plasma proteome of 43 COVID-19 patients with different outcomes by an untargeted liquid chromatography-mass spectrometry approach. The comparison between asymptomatic or pauci-symptomatic subjects (MILDs), and hospitalised patients in need of oxygen support therapy (SEVEREs) highlighted 29 proteins emerged as differentially expressed: 12 overexpressed in MILDs and 17 in SEVEREs. Moreover, a supervised analysis based on a decision-tree recognised three proteins (Fetuin-A, Ig lambda-2chain-C-region, Vitronectin) that are able to robustly discriminate between the two classes independently from the infection stage. In silico functional annotation of the 29 deregulated proteins pinpointed several functions possibly related to the severity; no pathway was associated exclusively to MILDs, while several only to SEVEREs, and some associated to both MILDs and SEVEREs; SARS-CoV-2 signalling pathway was significantly enriched by proteins up-expressed in SEVEREs (SAA1/2, CRP, HP, LRG1) and in MILDs (GSN, HRG). In conclusion, our analysis could provide key information for 'proteomically' defining possible upstream mechanisms and mediators triggering or limiting the domino effect of the immune-related response and characterizing severe exacerbations.