Background: Respiratory Syncytial Virus (RSV) is a significant cause of morbidity and mortality among lung transplant (LTx) recipients. Therapeutic options are limited, emphasizing the importance of prevention. The Arexvy^® vaccine (RSVPreF3) showed promising efficacy among immunocompetent adults; however, data on its immunogenicity in solid organ transplant recipients remain unclear. Methods: A single-center retrospective cohort study, including all LTx recipients who were vaccinated with Arexvy in February 2024. Baseline and follow-up serum samples (1, 3, and 6 months post-vaccination) were analyzed for antibody responses using a commercial RSV ELISA kit and micro-neutralization assays against historical reference RSV A/B ATCC strains and seasonal RSV strains. Adverse events were documented. Results: A total of 28 recipients received the vaccine. Twenty-one (75%) were male, and the median age was 62 years (interquartile range [IQR], 53–67). The median time from transplant was 486 days (IQR, 243–966). Vaccination elicited strong immunogenic responses, demonstrating a twofold increase in ELISA-determined antibody levels at one month post-vaccination, which were sustained for six months. At one month, 67% of recipients had antibody levels exceeding the cutoff threshold. Micro-neutralization assays showed a significant increase in neutralizing antibodies against all tested variants (RSV A/B ATCC and seasonal RSV A/B), with titers remaining at least twofold higher than pre-vaccination levels. No serious adverse events were observed. Conclusions: Our findings demonstrate a sustained antibody response to the Arexvy^® vaccine in a cohort of LTx recipients, with antibody titers sustained over six months. Further research is needed to assess the long-term durability of the immune response and the potential immunogenicity of this vaccine in LTx populations.

Background: Interstitial lung diseases (ILD) unresponsive to medical therapy often require lung transplantation (LTx), which prolongs quality of life and survival. Ideal timing for referral for LTx remains challenging, with late referral associated with significant morbidity and mortality. Among other criteria, patients with ILD should be considered for LTx if forced vital capacity (FVC) is less than 80% or diffusion capacity for carbon monoxide (DLCO) is less than 40%. However, data on referral rates are lacking. Objectives: To evaluate referral rates for LTx based on pulmonary function tests (PFTs) and identify barriers associated with non-referral. Design: A single-center retrospective cohort study. Methods: The study consisted of ILD patients who performed PFT between 2014 and 2020. Patients with FVC < 80% or a DLCO < 40% were included in the study. Patients with absolute contraindications to LTx were excluded. Referral rates were computed, and a comparison was made between referred and non-referred subjects. Results: Out of 114 ILD patients meeting criteria for referral to LTx, 35 were referred (30.7%), and 7 proceeded to undergo LTx. Median time from PFT to referral for assessment was 255 days [interquartile range (IQR) 35–1077]. Median time from referral to LTx was 89 days (IQR 59–143). Referred patients were younger ( p = 0.003), had lower FVC ( p < 0.001), DLCO ( p < 0.001), and a higher rate of pulmonary hypertension ( p = 0.04). Relatively better PFT, and older age, were significantly associated with non-referral of patients. Conclusion: There is under-referral of ILD patients who are eligible for LTx, which is associated with severe disease and missed opportunities for LTx. Further research is required to validate these findings.

Severe respiratory failure caused by COVID-19 often requires mechanical ventilation, including extracorporeal membrane oxygenation (ECMO). In rare cases, lung transplantation (LTx) may be considered as a last resort. However, uncertainties remain about patient selection and optimal timing for referral and listing. This retrospective study analyzed patients with severe COVID-19 who were supported by veno-venous ECMO and listed for LTx between July 2020 and June 2022. Out of the 20 patients in the study population, four who underwent LTx were excluded. The clinical characteristics of the remaining 16 patients were compared, including nine who recovered and seven who died while awaiting LTx. The median duration from hospitalization to listing was 85.5 days, and the median duration on the waitlist was 25.5 days. Younger age was significantly associated with a higher likelihood of recovery without LTx after a median of 59 days on ECMO, compared to those who died at a median of 99 days. In patients with severe COVID-19-induced lung damage supported by ECMO, referral to LTx should be delayed for 8–10 weeks after ECMO initiation, particularly for younger patients who have a higher probability of spontaneous recovery and may not require LTx.

Background: Neutrophils are key innate immune cells in peripheral blood. In recent years, sub-populations of neutrophils have been identified. In addition to the normal-density neutrophils (NDNs) in both healthy subjects and patients, low-density neutrophils (LDNs) were described in chronic inflammation and cancer. In lung transplants (LTx), neutrophils play crucial roles in reperfusion injury, acute rejection, and chronic lung allograft dysfunction. Our pilot study examines neutrophil subsets and function in LTx recipients during the first post-transplant year. Methods: We collected blood from 11 LTx recipients at various intervals. LDNs and normal-density neutrophils (NDNs) were isolated. The production of reactive oxygen species (ROS) by NDNs was measured after PMA activation using a Luminol-HRP assay. Neutrophil phenotypic markers were analyzed with flow cytometry. Results: The LDN-to-NDN ratio increased at 3 and 6 months post-transplant. Expression levels of CD62-L (aging marker), PDL-1 (immune checkpoint), CD15 (maturation), and CXCR4 (homeostasis regulator) showed modulation. Interestingly, ROS production by NDNs was mildly elevated at baseline, reduced at 6 months, and returned to baseline levels by 9 months post-transplant. Conclusions: Neutrophils exhibit dynamic changes in the first post-LTx year. Investigating neutrophil plasticity could reveal clinically relevant biomarkers and facilitate the development of diagnostic and therapeutic tools in LTx.

Background: Bronchoalveolar lavage (BAL) is frequently employed for diagnostic purposes in immunocompromised patients with pneumonia, yet its role in immunocompetent individuals remains debated. The study investigates whether BAL is associated with reduced mortality in immunocompetent patients hospitalized with pneumonia. Methods: A retrospective cohort study was conducted at SMC, including 13,180 immunocompetent patients hospitalized with pneumonia from 2007 to 2024. Patients who underwent BAL (n = 96) were matched 1: 4 to a control group (n = 384) using Propensity score matching based on age, gender, severity scores and comorbidities. Mortality was assessed at 30, 60, and 90 days using logistic regression models, adjusting for length of stay, inflammatory markers, albumin levels, smoking status, and BMI. Results: In the matched cohort, 30-day mortality did not differ significantly between groups (20.8% in BAL vs. 19.5% in controls, p = 0.886), and no significant association was observed after adjustment (OR = 0.95 [0.51–1.73]. However, both 60-day and 90-day mortality were significantly higher in the BAL group (39.6% vs. 24.7% and 45.8% vs. 26.8%, respectively; p < 0.01 for both), and these differences persisted after adjustment (60 days: OR = 1.74 [1.03–2.94]; 90 days: OR = 2.12 [1.27–3.54]). Conclusions: In this cohort of immunocompetent patients hospitalized with pneumonia, BAL was not associated with short-term survival. Clinicians should carefully weigh the potential risks and benefits of BAL in this population. Further studies are needed to identify patient subgroups that might benefit from BAL through enhanced diagnostic or therapeutic approaches.