Citations

Ehrlichiosis is a rare tick-borne zoonosis caused by Ehrlichia chaffeensis , E. ewingii and related species. In solid organ transplant recipients, immunosuppression can result in atypical presentations, delayed diagnosis and poor outcomes. The disease remains under-recognised among lung transplant recipients despite its potentially fatal course. A man in his early 70s with a history of bilateral lung transplantation for chronic obstructive pulmonary disease presented with a high-grade fever and shortness of breath. Bronchoalveolar lavage (BAL) culture grew Pseudomonas aeruginosa and meropenem was initiated. He subsequently developed severe thrombocytopenia, acute kidney injury and elevated liver transaminases. Disseminated intravascular coagulation (DIC) and thrombotic thrombocytopenic purpura (TTP) were excluded, while haemophagocytic lymphohistiocytosis (HLH) was considered but not confirmed. His condition rapidly progressed to multiorgan failure requiring mechanical ventilation and haemodialysis. E. chaffeensis was identified postmortem by next-generation sequencing. This case highlights diagnostic challenges and the importance of early empiric doxycycline therapy in endemic areas.

ABSTRACT Celiac disease (CD) is an autoimmune enteropathy with recognized extraintestinal manifestations. We describe a 55‐year‐old man with long‐standing, well‐controlled CD who developed progressive shortness of breath and cough. Imaging was indeterminate for usual interstitial pneumonia (UIP), and a surgical lung biopsy demonstrated a UIP pattern. Autoimmune serologies were negative, and no alternate etiologies for UIP were identified. With intermittent adherence to a gluten‐free diet and medical management including nintedanib, his disease progressed, ultimately leading to lung transplantation. This case raises the possibility of an association between CD and UIP of uncertain aetiology and should prompt further discussion as the relationship remains unclear. To contextualize this observation, we conducted a systematic review of published case reports evaluating pulmonary manifestations of celiac disease.

Abstract Rationale Acute cellular rejection (ACR) within first-year post-lung transplantation has important implications for prognosis. Calcineurin inhibitors (CNI), including tacrolimus or cyclosporine, along with cell cycle inhibitors (CCI) and steroids, remain the standard immunosuppression regimen post-transplant. Although tacrolimus is used as the primary CNI, target therapeutic levels vary across recipients due to adverse effects and tolerability, sometimes requiring switching over to Cyclosporine. We hypothesized that ACR within the first year is associated with switching CNI from Tacrolimus to Cyclosporine. Methods We performed a cross-sectional study of 255 adult lung transplant recipients between June 2019 to November 2024 at Mayo Clinic, Florida. Demographics, induction regimens, CNI type and their levels (average low and high levels) were compared between the 2 groups. The institutional maintenance immunosuppression regimen is Tacrolimus, Mycophenolate Mofetil (MMF) and prednisone, but could be switched to Cyclosporine if the previous regimen is not tolerated. The primary outcome was ACR <1 year diagnosed based on biopsy and/or clinical criteria. Comparisons between groups were performed using Chi-Square test for categorical variables and t-test or Wilcoxon Rank sum test for continuous variables. Multivariable regression analysis was performed with ACR <1 year as the outcome to adjust for the confounders. Results Our cohort included 255 lung transplant recipients with median age of 63 years, 61% Male, 84% Caucasians, 88% bilateral lung transplant (Further details elucidated in Table 1). A total of 173 (67%) out of 255 patients had ACR <1 year. The group with ACR < 1 year had higher proportion of Interstitial Lung Disease (ILD) (81% vs 68%, p = 0.044), use of Basiliximab for induction (70% vs 55%, p = 0.018), and cyclosporine instead of tacrolimus (23% vs 11%, p = 0.027). Group with ACR <1 year also had higher Antibody Mediated Rejection (AMR) < 1year (15% vs 6.1%, p = 0.041) and higher CLAD (BOS 0p-3: 43% vs 25.6%, p = 0.033) compared to the group without ACR < 1 year (Table 1.1). Multivariate regression analysis showed ILD (adjusted odds ratio, aOR 2.84, 95% CI 1.31 - 6.27, p = 0.008) and use of cyclosporine (aOR 2.55, 95% CI 1.07 - 6.78, p = 0.034) as independent predictors of ACR < 1 year (Table 2). Conclusions The presence of ACR < 1 year was associated with the use of Cyclosporine over Tacrolimus as a maintenance regimen. Also, ACR < 1year was associated with higher AMR and CLAD. Further prospective studies are needed to study this long-term given its significant prognostic implications. This abstract is funded by: Not Applicable

Abstract Background Lung transplantation remains the accepted treatment modality of choice for life-threatening advanced lung disease due to established benefits of improving survival and functional status of the patients. However, the annual mortality of lung waitlist candidates remains high, reflecting ongoing donor-recipient mismatches and prolonged wait times. Modalities such as extracorporeal membrane oxygenation (ECMO) have been effectively used as a “bridge to transplant” (BTT) in high-risk patients on waitlist. Objective To evaluate trends in ECMO utilization, waitlist dynamics, and outcomes among lung transplant candidates between 2018 and 2024, with emphasis on the use of ECMO as a bridge to transplantation. Methods We conducted a retrospective chart review of all ECMO runs performed between 2018 to 2024 at the Mayo Clinic Florida Hospital. Among these, patients who underwent evaluation for lung transplantation were identified, and their waitlisting patterns, transplant outcomes, and peri-transplant ECMO status were described. Results Between 2018 and 2024, a total of 348 ECMO runs were recorded among 293 patients. Annual ECMO runs increased steadily from 17 in 2018 to 83 in 2024 (2019: 33, 2020: 30, 2021: 61, 2022: 56, 2023: 68, 2024: 83). Out of these patients, 142 underwent evaluation for lung transplantation and 133 (93.67%) were placed on the waitlist. Among waitlisted patients, 105 (78.9%) were listed before ECMO initiation, 23 (17.3%) during ECMO, and 5 (3.8%) after decannulation. Waitlist outcomes included 116 (87.2%) transplanted, 16 (12.0%) deaths before transplant, and 1 (0.8%) clinical improvement precluding transplant. Among 116 transplanted patients, 36 patients (31.03%) received ECMO as a bridge to lung transplantation. The annual patients bridged with ECMO demonstrated a progressive rise: 1 (2019), 3 (2020), 9 (2021), 6 (2022), 9 (2023), and 8 (2024). Among these 36 patients, 29 (80.56%) remained on ECMO support in the immediate post-transplant period. At the latest follow-up, mortality among BTT recipients was 9 (25%). Conclusion ECMO utilization has expanded substantially over the past several years reflecting its expanding role in supporting critically ill patients. There has been increased utilization of ECMO as a bridge to lung transplantation in order to support high risk candidates awaiting donor organs. The post-transplant mortality among BTT recipients was 25%, which highlights the importance of peri-transplant management to optimize long-term outcomes in this high-risk cohort. This abstract is funded by: None

ABSTRACT Background Treating Mycobacterium avium complex (MAC) infection pre‐lung transplant (LT) can be challenging to treat, given prolonged therapy and side effects. The impact of pre‐transplant MAC treatment on recurrence and outcomes post‐LT remains unclear, especially in patients with interstitial lung disease (ILD) who have a median survival of less than 2 years. Methods We performed a retrospective cohort study of adult LT patients at the Mayo Clinic who had positive MAC sputum cultures pre‐LT. The cohort was stratified and compared based on the type of treatment (complete, partial, or no treatment) for MAC pulmonary infection. The primary outcome was MAC recurrence post‐LT, and secondary outcomes were mortality, FEV‐1, and FVC at 1‐year post‐LT. Results Among the cohort of 47 patients, 9 (19.1%) were partially treated and 11 (23.4%) were completely treated for MAC infection pre‐LT. Post‐transplant MAC pulmonary infection recurrence occurred in eight (17%) of the total cohort, with four (14.8%) in the non‐treated, four (44.4%) in the partially‐treated, and none (0%) in the completely treated patients ( p = 0.026). There was no difference in mortality in patients who had MAC recurrence post‐transplantation (13% vs. 9.7%, p > 0.9) and those who were completely or partially treated, compared to non‐treated (0% vs. 13% vs. 13%, p > 0.9). The FEV1 and FVC at 1‐year post‐LT did not differ by the pre‐transplant treatment or post‐transplant MAC recurrence status. Conclusion The role of treatment for MAC infection pre‐transplant is questionable, especially in patients with diseases like ILD who may not have enough wait time to complete therapy.

Abstract Introduction: The data on outcomes comparing lung transplantation with ABO-identical versus ABO-compatible blood group is limited. Composite Allocation Score(CAS) was introduced on March 9th, 2023, and has considered additional points for the difficult-to-match blood group. We aimed to study the trend and outcomes of patients who underwent lung transplants with ABO identical versus compatible blood groups. Methods: We queried the United Network of Organ Sharing (UNOS) database of those who underwent lung transplantation between 10/1/1987 to 3/31/2024 and compared the outcomes between those who had ABO-identical vs ABO-compatible blood groups. Combined organ transplants and recipients age <18 were excluded. Results: A total of 50,406 patients were included in our study, out of which 4,111 (8.15%) were ABO-compatible and 47,347 (91.85%) were ABO-identical. Among the recipient demographics, the ABO-compatible group compared to the ABO-identical group showed a lesser lung allocation score (40 ± 16 vs 42 ± 16), but higher A-blood group (59% vs 38%), obstructive lung disease (38% vs 33%), CAS (49 ± 13 vs 47 ± 10), mechanical ventilator support pre-transplant (6.2% vs 5.2%), need for ex-vivo lung perfusion (9.6% vs 5.8%) and listing for single lung transplant (39% vs 34%), all p<0.05. The donors for the ABO-compatible group had a closer distance to the transplant center (205 ± 285 vs 226 ± 265 nautical miles), lesser white race (61% vs 64%), and gender mismatch (30% vs 32%) but higher male gender (64% vs 61%), O-blood group (81% vs 49%) and ethnicity mismatch (45% vs 41%), all p<0.05. The univariate analysis showed a higher 30-day (7.2% vs 5.8%), 1-year (22% vs 19%), and 5-year (54% vs 50%) mortality among patients with ABO-compatible compared to ABO-identical recipients, all p<0.001. However, the adjusted odds ratio of 30-day (0.76, 95% CI 0.36-1.47, p=0.4), 1-year (1.07, 95% CI 0.69-1.66, p=0.7) and 5-year (0.69, 95% CI 0.46-1.05, p=0.081) mortality were not statistically significant with ABO-identical when compared to ABO-compatible group on adjusting to the covariates in the multivariate analysis. The trend of ABO-compatible lung transplantation has been increasing with the introduction of CAS (figure 1). Conclusion: Patients who underwent lung transplantation with the ABO-compatible blood group donor organs had similar outcomes compared to the ABO-identical blood group. The findings of our study reinforce the importance of increasing the use of ABO-compatible organs to enhance the lung transplantation rate, aligning with the observed trend following the introduction of CAS.

BackgroundThe DelIVery for Pulmonary Arterial Hypertension clinical trial was a multi‐center, prospective, single arm, Investigational Device Exemption study utilizing a fully implantable, programmable intravascular delivery system consisting of a pump and a catheter for intravenous treprostinil. The study met its primary endpoint and demonstrated that the intravascular delivery system significantly reduced catheter related complications at 22,000 subject‐days of follow‐up compared with a predefined objective performance criterion. Here we summarize the results obtained during a 6.4‐year follow‐up period.MethodsThroughout study follow‐up, participants had clinic visits and medication refills at least every 12 weeks (dependent on the subjects’ dose). All adverse events and intravascular delivery system complications were evaluated and recorded.ResultsSixty pulmonary arterial hypertension subjects were followed post device implantation for approximately 282 patient‐years (range 87 days to 6.4 years). Of the 60 subjects, 14 died (1 related to intravascular delivery system pump failure), 2 withdrew after lung transplants, and 2 withdrew due to pump pocket infection. No catheter‐related bloodstream infections, catheter thrombosis or occlusions, or catheter kinks occurred through 282 patient‐years. Two participants had adverse events of abdominal pain, rash, due to subcutaneous treprostinil “leaks” after one catheter puncture and one catheter laceration during pump refill and replacement, respectively. Eight pump failure events occurred: seven pump motor stalls and one early replacement (faulty battery).ConclusionDelivery of treprostinil with an intravascular delivery system is a safe alternative to an external delivery system, while providing enhanced life experiences. To preserve the risk–benefit ratio, treatment at specialized pulmonary arterial hypertension centers is recommended until training is disseminated at other sites.