Release of IL-1ß and IL-18 in human primary bronchial epithelial cells exposed to cigarette smoke is independent of NLRP3.

Cigarette smoke (CS) is a major risk factor for chronic lung diseases and promotes activation of pattern recognition receptors in the bronchial epithelium. NOD-like receptor family, pyrin domain-containing 3 (NLRP3) is a pattern recognition receptor whose activation leads to caspase-1 cleavage, maturation/release of IL-1ß and IL-18, and eventually pyroptosis. Whether the NLRP3 inflammasome participates in CS-induced inflammation in bronchial epithelial cells is still unclear. Herein, we evaluated the involvement of NLRP3 in CS-induced inflammatory responses in human primary bronchial epithelial cells. To this purpose, human primary bronchial epithelial cells were stimulated with CS extracts (CSE) and lytic cell death, caspase activation (-1, -8, -3/7), cytokine release (IL-1ß, IL-18, and IL-8), NLRP3, pro-IL-1ß/pro-IL-18 mRNA, and protein expression were measured. The impact of inhibitors of NLRP3 (MCC950), caspases, and the effect of the antioxidant N-acetyl cysteine were evaluated. We found that CSE increased pro-IL-1ß expression and induced activation of caspase-1 and release of IL-1ß and IL-18. These events were independent of NLRP3 and we found that NLRP3 was not expressed. N-acetyl cysteine reverted CSE-induced caspase-1 activation. Overall, our findings support that the bronchial epithelium may play a central role in the release of IL-1 family cytokines independently of NLRP3 in the lungs of smokers.

Donor-derived carbapenem-resistant gram-negative bacterial infections in solid organ transplant recipients: Active surveillance enhances recipient safety.

Donor-derived infections (DDIs) caused by carbapenem-resistant gram-negative bacteria (CR-GNB) in solid organ transplant recipients are potentially life-threatening. In this prospective study, we evaluated the incidence, factors associated with transmission, and the outcome of recipients with unexpected CR-GNB DDIs after the implementation of our local active surveillance system (LASS). LASS provides for early detection of unexpected donor CR-GNB infections, prophylaxis of recipients at high risk, and early diagnosis and treatment of DDIs. Whole genome sequencing confirmed DDI. Among 791 recipients, 38 (4.8%) were at high risk of unexpected CR-GNB DDI: 25 for carbapenem-resistant Enterobacterales (CRE) and 13 for carbapenem-resistant Acinetobacter baumannii (CRAB). Transmission did not occur in 27 (71%) cases, whereas DDIs occurred in 9 of 25 of CRE and 2 of 13 of CRAB cases. Incidence of CR-GNB DDI was 1.4%. Recipients of organs with CR-GNB-positive preservation fluid and liver recipients from a donor with CRE infection were at the highest risk of DDI. There was no difference in length of hospital stay or survival in patients with and without CR-GNB DDI. Our LASS contains transmission and mitigates the negative impacts of CR-GNB DDI. Under well-defined conditions, organs from donors with CR-GNB may be considered after a thorough evaluation of the risk/benefit profile.

Lung transplantation in HIV seropositive recipients: An analysis of the UNOS registry.

BACKGROUND: Experience with lung transplantation (LT) in patients with human immunodeficiency virus (HIV) is limited. Many studies have demonstrated the success of kidney and liver transplantation in HIV-seropositive (HIV+) patients. Our objective was to conduct a national registry analysis comparing LT outcomes in HIV+ to HIV-seronegative (HIV-) recipients. METHODS: The United Network for Organ Sharing database was queried to identify LTs performed in adult HIV+ patients between 2016 and 2023. Patients with unknown HIV status, multiorgan transplants, and redo transplants were excluded. The primary endpoints were mortality and graft rejection. Survival time was analyzed using Kaplan-Meier analysis. RESULTS: The study included 17 487 patients, 67 of whom were HIV+. HIV+ recipients were younger (59 vs. 62 years, p = .02), had higher pulmonary arterial pressure (28 vs. 25 mm Hg, p = .04), and higher lung allocation scores (47 vs. 41, p = .01) relative to HIV- recipients. There were no differences in graft/recipient survival time between groups. HIV+ recipients had higher rates of post-transplant dialysis (18% vs. 8.4%, p = .01), but otherwise had similar post-transplant outcomes to HIV-recipients. CONCLUSIONS: This national registry analysis suggests LT outcomes in HIV+ patients are not inferior to outcomes in HIV- patients and that well-selected HIV+ recipients can achieve comparable patient and graft survival rates relative to HIV- recipients.

Donor-derived mold infections in lung transplant recipients: The importance of active surveillance.

Unexpected donor-derived fungal infections represent a rare but potentially fatal complication in lung transplant (Tx) recipients. Timely communication of the results of donor cultures and prompt treatment of recipients are crucial to mitigate the consequences of donor-derived transmissions. In this prospective cohort study, all consecutive patients who underwent lung transplantation from 2015 to 2022 were included. In December 2015, a Local Active Surveillance System has been implemented to provide biovigilance of donor culture results and optimize recipients' management. The aim of this study is to investigate the incidence of unexpected, mold-positive cultures among lung donors and the rate of transmission to recipients. Furthermore, management strategies and outcome of recipients with mold transmission are described. In case of isolation of the same mold in donor and recipient cultures, when possible, transmission was confirmed by dendrogram analysis. During the study period, 82 lung Tx were performed from 80 donors. The prevalence of donors with "unexpected" mold isolation from the respiratory tract was 3.75% (3/80). Isolated molds were Aspergillus niger, Rhizopus oryzae, and Aspergillus flavus. Transmissions occurred in all the three cases (100%) with a mean time of 5 days from lung Tx but none of the recipients developed invasive mold disease. Our Local Active Surveillance System allowed prompt recognition of lung donors unexpected mold colonization. Even though transmission occurred, introduction of early targeted antifungal therapy prevented potential catastrophic consequence of mold donor-derived infection in the immediate post-Tx period.

Proteomic analysis and functional validation reveal distinct therapeutic capabilities related to priming of mesenchymal stromal/stem cells with IFN-γ and hypoxia: potential implications for their clinical use.

Mesenchymal stromal/stem cells (MSCs) are a heterogeneous population of multipotent cells that can be obtained from various tissues, such as dental pulp, adipose tissue, bone marrow and placenta. MSCs have gained importance in the field of regenerative medicine because of their promising role in cell therapy and their regulatory abilities in tissue repair and regeneration. However, a better characterization of these cells and their products is necessary to further potentiate their clinical application. In this study, we used unbiased high-resolution mass spectrometry-based proteomic analysis to investigate the impact of distinct priming strategies, such as hypoxia and IFN-γ treatment, on the composition and therapeutic functionality of the secretome produced by MSCs derived from the amniotic membrane of the human placenta (hAMSCs). Our investigation revealed that both types of priming improved the therapeutic efficacy of hAMSCs, and these improvements were related to the secretion of functional factors present in the conditioned medium (CM) and exosomes (EXOs), which play crucial roles in mediating the paracrine effects of MSCs. In particular, hypoxia was able to induce a pro-angiogenic, innate immune response-activating, and tissue-regenerative hAMSC phenotype, as highlighted by the elevated production of regulatory factors such as VEGFA, PDGFRB, ANGPTL4, ENG, GRO-γ, IL8, and GRO-α. IFN-γ priming, instead, led to an immunosuppressive profile in hAMSCs, as indicated by increased levels of TGFB1, ANXA1, THBS1, HOMER2, GRN, TOLLIP and MCP-1. Functional assays validated the increased angiogenic properties of hypoxic hAMSCs and the enhanced immunosuppressive activity of IFN-γ-treated hAMSCs. This study extends beyond the direct priming effects on hAMSCs, demonstrating that hypoxia and IFN-γ can influence the functional characteristics of hAMSC-derived secretomes, which, in turn, orchestrate the production of functional factors by peripheral blood cells. This research provides valuable insights into the optimization of MSC-based therapies by systematically assessing and comparing the priming type-specific functional features of hAMSCs. These findings highlight new strategies for enhancing the therapeutic efficacy of MSCs, particularly in the context of multifactorial diseases, paving the way for the use of hAMSC-derived products in clinical practice.

Tixagevimab/Cilgavimab as SARS-CoV-2 Pre-Exposure Prophylaxis in Lung Transplant Recipients during the Omicron Wave: A Real-World Monocentric Experience.

Lung transplant recipients (LTRs) respond poorly to vaccination. SARS-CoV-2 pre-exposure prophylaxis (PrEP) with tixagevimab/cilgavimab (TIX/CIL) reduces the incidence of infection and the evolution to severe COVID-19. In vitro data show decreased activity against Omicron variants. We evaluated the clinical efficacy and safety of TIX/CIL in LTRs during the Omicron wave. A prospective observational cohort study was conducted at ISMETT in Palermo (Italy). In June 2022, SARS-CoV-2 PrEP with TIX/CIL 150/150 mg was offered to LTRs. LTRs who received TIX/CIL were compared to LTRs who did not. Logistic regression analysis (adjusted for prior COVID-19, SARS-CoV-2 vaccination, age, years from transplant, and rejection) was performed. The objective of this study was to compare the following among the two populations: prevalence of SARS-CoV-2, length of SARS-CoV-2 positivity, and COVID-19 disease severity. Among 110 eligible LTRs, 79 (72%) received TIX/CIL and 31 (28%) did not. SARS-CoV-2 infections occurred in 6% (n = 5) of patients who received TIX/CIL and 29% (n = 9) of patients who did not (p < 0.001). In both groups, infections were mild/asymptomatic, and no one was hospitalized or died. At multivariate analysis, TIX/CIL was associated with a lower risk of infection (aOR 0.22; 95%CI 0.06-0.78; p = 0.02). TIX/CIL was safe and effective in reducing the risk of SARS-CoV-2 in LTRs during the Omicron wave.

Successful multidisciplinary urgent management of life-threatening intraprocedural bleeding after EUS-guided fine-needle biopsy of a pulmonary mass.

Video 1Multidisciplinary management of an intraprocedural endobronchial bleeding after EUS-guided transesophageal FNB of a pulmonary mass.