The crucial role of stability of intercalating agent for DNA binding studies in DMSO/water system

In recent years, extensive research has been directed towards understanding the interactions between various zinc complexes with DNA, specifically delving into their intercalation and binding behaviors. The binding of zinc complexes to DNA is particularly intriguing due to their distinctive intercalating capabilities. This study unveils a remarkable phenomenon observed with a specific Zn complex, ([B-Zn-N3], where B is a Schiff base ligand), during DNA intercalation investigations in the popular DMSO-Water binary solvent mixture. An unanticipated observation revealed time-dependent changes in the UV-visible absorption spectroscopic studies, coupled with the existence of an isosbestic point. This observation questions the stability of the intercalating agent itself during the intercalation process. The emergence of a decomposed product during the intercalation study has been confirmed through various analytical techniques, including CHN analysis, MALDI mass, XPS, Raman spectroscopy, and Powder XRD. The change in the chemical species on intercalation is further substantiated by theoretical studies, adding depth to our understanding of the intricate dynamics at play during DNA intercalation with the [B-Zn-N3] complex in the DMSO-Water system.

Evaluating the efficacy and safety of letermovir compared to valganciclovir for the prevention of human cytomegalovirus disease in adult lung transplant recipients

BACKGROUND

Lung transplant recipients are at high risk for severe cytomegalovirus (CMV) disease. Off-label use of letermovir (LET) may avert myelotoxicity associated with valganciclovir (VGCV), but data in lung transplantation are limited. This study aims to evaluate the outcomes of LET prophylaxis among lung transplant recipients.

METHODS

This retrospective, matched cohort study included lung transplant recipients who received LET for primary CMV prophylaxis following VGCV intolerance. Patients were matched 1:1 to historical VGCV controls based on age, serostatus group, and time from transplant. The primary outcome was CMV breakthrough within 1 year post-LET initiation; secondary outcomes included hematologic changes.

RESULTS

A total of 124 lung transplant recipients were included per group (32% CMV mismatch, D+R-), with LET initiated a median of 9.6 months post-transplantation. One CMV breakthrough event (0.8%) was observed in the LET group versus four (3.2%) in the VGCV group (p = .370). The median (interquartile range) white blood cell (WBC) count was 3.1 (2.1-5.6) at LET initiation which increased to 5.1 (3.9-7.2) at the end of follow-up (p <.001). For VGCV controls, WBC was 4.8 (3.4-7.2) at baseline and 5.4 (3.6-7.2) at the end of follow-up; this difference was not statistically significant (p = .395). Additionally, 98.4% of LET patients experienced ≥1 leukopenia episode in the year prior to LET compared to 71.8% the year after initiation (p <.001). Similar results were observed for neutropenia (48.4% and 17.7%, p <.001).

CONCLUSION

LET prophylaxis was associated with a low rate of CMV reactivation and leukopenia recovery. LET may represent a reasonable prophylaxis option for lung transplant recipients unable to tolerate VGCV.

Shining light on tryptamine-derived isocyanides: access to constrained spirocylic scaffolds

Dearomatization of indoles through a charge transfer complex constitutes a powerful tool for synthesizing three-dimensional constrained structures. However, the implementation of this strategy for the dearomatization of tryptamine-derived isocyanides to generate spirocyclic scaffolds remains underdeveloped. In this work, we have demonstrated the ability of tryptamine-derived isocyanides to form aggregates at higher concentration, enabling a single electron transfer step to generate carbon-based-radical intermediates. Optical, HRMS and computational studies have elucidated key aspects associated with the photophysical properties of tryptamine-derived isocyanides. The developed protocol is operationally simple, robust and demonstrates a novel approach to generate conformationally constrained spirocyclic scaffolds, compounds with high demand in various fields, including drug discovery.

An objective way to predict remission and relapse in Cushing disease using Bayes' theorem of probability

OBJECTIVE

In this study on patients with Cushing disease, post-transsphenoidal surgery (TSS), we attempt to predict the probability of remaining in remission, at least for a year and relapse after that, using Bayes' theorem and the equation of conditional probability. The number of parameters, as well as the weightage of each, is incorporated in this equation.

DESIGN AND METHODS

The study design was a single-centre ambispective study. Ten clinical, biochemical, radiological and histopathological parameters capable of predicting Cushing disease remission were identified. The presence or absence of each parameter was entered as binary numbers. Bayes' theorem was applied, and each patient's probability of remission and relapse was calculated.

RESULTS

A total of 145 patients were included in the study. ROC plot showed a cut-off value of the probability of 0.68, with a sensitivity of 82% (range 73-89%) and a specificity of 94% (range 83-99%) to predict the probability of remission. Eighty-one patients who were in remission at 1 year were followed up for relapse and 23 patients developed relapse of the disease. The Bayes' equation was able to predict relapse in only 3 out of 23 patients.

CONCLUSIONS

Using various parameters, remission of Cushing disease can be predicted by applying Bayes' theorem of conditional probability with a sensitivity and a specificity of 82% and 94%, respectively. This study provided an objective way of predicting remission after TSS and relapse in patients with Cushing disease giving a weightage advantage to every parameter.

Cell-type-specific and disease-associated expression quantitative trait loci in the human lung

Common genetic variants confer substantial risk for chronic lung diseases, including pulmonary fibrosis. Defining the genetic control of gene expression in a cell-type-specific and context-dependent manner is critical for understanding the mechanisms through which genetic variation influences complex traits and disease pathobiology. To this end, we performed single-cell RNA sequencing of lung tissue from 66 individuals with pulmonary fibrosis and 48 unaffected donors. Using a pseudobulk approach, we mapped expression quantitative trait loci (eQTLs) across 38 cell types, observing both shared and cell-type-specific regulatory effects. Furthermore, we identified disease interaction eQTLs and demonstrated that this class of associations is more likely to be cell-type-specific and linked to cellular dysregulation in pulmonary fibrosis. Finally, we connected lung disease risk variants to their regulatory targets in disease-relevant cell types. These results indicate that cellular context determines the impact of genetic variation on gene expression and implicates context-specific eQTLs as key regulators of lung homeostasis and disease.

Evolving impact of the COVID-19 pandemic on lung transplant recipients: A single-center experience

BACKGROUND

Lung transplant recipients (LTRs) are at increased risk of morbidity and mortality from coronavirus disease 2019 (COVID-19); however, the disease course has changed as severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) variants have mutated. We compared COVID-19-related clinical outcomes in LTRs at different stages of the pandemic. We also identified risk factors for developing severe COVID-19 independent of the dominant SARS-CoV-2 variant.

METHODS

This single-center, retrospective cohort study of LTRs with COVID-19 used Cox regression analyses and bootstrapping to identify factors affecting COVID-19 severity.

RESULTS

Between March 2020 and August 2022, 195 LTRs were diagnosed with COVID-19, almost half (89 [45.6%]) during the Omicron period. A total of 113 (58.5%) LTRs were hospitalized and 47 (24.1%) died. Age >65 years increased the risk of hospitalization and death. Although infection with the Omicron variant was associated with a lower risk of hospitalization, the median length of hospital stay (10 days, [interquartile range, 5-19]) was similar between the variants. Intensive care unit (ICU) admission and death were more common with the Delta variant but comparable between the original, Alpha, and Omicron variants. Remdesivir and molnupiravir reduced the risk of hospitalization, and monoclonal antibody therapy reduced the risk of ICU admission, intubation, and death. Vaccination and pre-exposure prophylaxis (PrEP) with tixagevimab-cilgavimab did not significantly reduce COVID-19-related ICU admission, intubation, or mortality among LTRs.

CONCLUSIONS

LTRs with COVID-19 continue to have high hospitalization rates and prolonged hospital stays, despite the reduced virulence of the Omicron variant. More effective PrEP and therapeutic interventions for COVID-19 among vulnerable patient groups are needed.

Late-Onset Exudative Pleural Effusions Without Concomitant Airway Obstruction or Lung Parenchymal Abnormalities: A Novel Presentation of Chronic Lung Allograft Dysfunction

Restrictive allograft syndrome (RAS) is an aggressive variant of CLAD characterized by progressive restrictive ventilatory decline and persistent pleuro-parenchymal changes that can be seen on chest CT. We identified four lung transplant recipients with a progressive restrictive ventilatory defect due to lymphocyte-predominant exudative pleural effusions, but no pleuro-parenchymal abnormalities typical of RAS. Using molecular analysis, we also found increased levels of previously described immune markers of RAS, including NFkB, 20S proteasome, lipocalin, TNFα, and TGFβ, within the circulating small extracellular vesicles of the remaining living lung transplant recipient. Despite the absence of lung parenchymal changes, these patients had a poor prognosis with rapid deterioration in allograft function and no response to pleural-based interventions such as thoracentesis, decortication, and pleurodesis. We hypothesize that these cases represent a distinct CLAD phenotype characterized by progressive restriction due to pleural inflammation, lymphocyte-predominant pleural effusion, resultant compressive atelectasis, and eventual respiratory failure in the absence of lung parenchymal involvement.

Efficient, narrow-band, and stable electroluminescence from organoboron-nitrogen-carbonyl emitter

Organic light-emitting diodes (OLEDs) exploiting simple binary emissive layers (EMLs) blending only emitters and hosts have natural advantages in low-cost commercialization. However, previously reported OLEDs based on binary EMLs hardly simultaneously achieved desired comprehensive performances, e.g., high efficiency, low efficiency roll-off, narrow emission bands, and high operation stability. Here, we report a molecular-design strategy. Such a strategy leads to a fast reverse intersystem crossing rate in our designed emitter h-BNCO-1 of 1.79×105 s-1. An OLED exploiting a binary EML with h-BNCO-1 achieves ultrapure emission, a maximum external quantum efficiency of over 40% and a mild roll-off of 14% at 1000 cd·m-2. Moreover, h-BNCO-1 also exhibits promising operational stability in an alternative OLED exploiting a compact binary EML (the lifetime reaching 95% of the initial luminance at 1000 cd m-2 is ~ 137 h). Here, our work has thus provided a molecular-design strategy for OLEDs with promising comprehensive performance.

Image-based spatial transcriptomics identifies molecular niche dysregulation associated with distal lung remodeling in pulmonary fibrosis

The human lung is structurally complex, with a diversity of specialized epithelial, stromal and immune cells playing specific functional roles in anatomically distinct locations, and large-scale changes in the structure and cellular makeup of this distal lung is a hallmark of pulmonary fibrosis (PF) and other progressive chronic lung diseases. Single-cell transcriptomic studies have revealed numerous disease-emergent/enriched cell types/states in PF lungs, but the spatial contexts wherein these cells contribute to disease pathogenesis has remained uncertain. Using sub-cellular resolution image-based spatial transcriptomics, we analyzed the gene expression of more than 1 million cells from 19 unique lungs. Through complementary cell-based and innovative cell-agnostic analyses, we characterized the localization of PF-emergent cell-types, established the cellular and molecular basis of classical PF histopathologic disease features, and identified a diversity of distinct molecularly-defined spatial niches in control and PF lungs. Using machine-learning and trajectory analysis methods to segment and rank airspaces on a gradient from normal to most severely remodeled, we identified a sequence of compositional and molecular changes that associate with progressive distal lung pathology, beginning with alveolar epithelial dysregulation and culminating with changes in macrophage polarization. Together, these results provide a unique, spatially-resolved characterization of the cellular and molecular programs of PF and control lungs, provide new insights into the heterogeneous pathobiology of PF, and establish analytical approaches which should be broadly applicable to other imaging-based spatial transcriptomic studies.

Immune responses of lung transplant recipients against SARS-CoV-2 and common respiratory coronaviruses: Evidence for pre-existing cross-reactive immunity

Humoral and cellular immune responses to SARS-CoV-2 and other coronaviruses in lung transplant recipients are unknown. We measured antibodies and T cell responses against the SARS-CoV-2 spike S2 and nucleocapsid antigens and spike antigens from common respiratory coronaviruses (229E, NL63, OC43, and HKU1) after vaccination or infection of LTxRs. 148 LTxRs from single center were included in this study: 98 after vaccination and 50 following SARS-CoV-2 infection. Antibodies were quantified by enzyme-linked immunosorbent assay. The frequency of T cells secreting IL2, IL4, IL10, IL17, TNFα, and IFNγ were enumerated by enzyme-linked immunospot assay. Our results have shown the development of antibodies to SARS-CoV-2 spike protein in infected LTxRs (39/50) and vaccinated LTxRs (52/98). Vaccinated LTxRs had higher number of T cells producing TNFα but less cells producing IFNγ than infected LTxRs in response to the nucleocapsid antigen and other coronavirus spike antigens. We didn't find correlation between the development of antibodies and cellular immune responses against the SARS-CoV-2 spike protein after vaccination. Instead, LTxRs have pre-existing cellular immunity to common respiratory coronaviruses, leading to cross-reactive immunity against SARS-CoV-2 which likely will provide protection against SARS-Cov-2 infection.

Prior SARS-CoV-2 infection may not alter the clinical course of COVID-19 in lung transplant recipients: A single-center experience

BACKGROUND

In the general population, prior infection with SARS-CoV-2 reduces the risk of severe COVID-19; however, studies in lung transplant recipients (LTRs) are lacking. We sought to describe the clinical course of COVID-19 recurrence and compare outcomes between the first and second episodes of COVID-19 in LTRs.

METHODS

We conducted a retrospective, single-center cohort study of LTRs with COVID-19 between January 1, 2022, and September 30, 2022, during the Omicron wave. We compared the clinical course of a second episode of COVID-19 to that of the patients' own first episode and to that of LTRs who developed a first episode during the study period.

RESULTS

During the study period, we identified 24 LTRs with COVID-19 recurrence and another 75 LTRs with a first episode of COVID-19. LTRs who survived the initial episode of COVID-19 had a similar disease course with recurrence, with a trend toward reduced hospitalization (10 (41.6%) vs. 4 (16.7%), p = .114). Furthermore, compared to LTRs with a primary infection during the Omicron wave, those with a reinfection had a non-statistically significant trend toward reduced hospitalizations (aOR .391, 95% CI [.115-1.321], p = .131), shorter lengths-of-stay (median, 4 vs. 9 days, p = .181), and reduced intensive care unit admissions, intubations, and COVID-19-related mortality.

CONCLUSIONS

LTRs who survive the first episode of COVID-19 are likely to have a similar clinical course with recurrent episodes. Although recurrent COVID-19 may be milder, larger, well-powered studies are needed to confirm this observation. Ongoing precautions are warranted.

A randomized controlled trial of presatovir for respiratory syncytial virus after lung transplant

BACKGROUND

Respiratory syncytial virus (RSV) infection in lung transplant recipients is associated with high morbidity. This study evaluated the RSV fusion inhibitor presatovir in RSV-infected lung transplant recipients.

METHODS

In this international Phase 2b, randomized, double-blind, placebo-controlled trial (NCT02534350), adult lung transplant recipients with symptomatic confirmed RSV infection for ≤7 days received oral presatovir 200 mg on day 1 and 100 mg daily on days 2 to 14, or placebo (2:1), with follow-up through day 28. There were 2 coprimary endpoints: time-weighted average change in nasal RSV load from day 1 to 7, calculated from nasal swabs, in the full analysis set ([FAS]; all patients who received study drug and had quantifiable baseline nasal RSV load) and time-weighted average change in nasal RSV load from day 1 to 7 in the subset of patients with pretreatment symptom duration at the median or shorter of the FAS. Secondary endpoints were changes in respiratory infection symptoms assessed using the Influenza Patient-Reported Outcomes questionnaire and lung function measured by spirometry.

RESULTS

Sixty-one patients were randomized, 40 received presatovir, 20 placebo, and 54 were included in efficacy analyses. Presatovir did not significantly improve the primary endpoint in the FAS (treatment difference [95% CI], 0.10 [-0.43, 0.63] log10 copies/ml; p = 0.72) or the shorter symptom-duration subgroup (-0.12 [-0.94, 0.69] log10 copies/ml; p = 0.76). Secondary endpoints were not different between presatovir and placebo groups. Presatovir was generally well tolerated.

CONCLUSIONS

Presatovir treatment did not significantly improve change in nasal RSV load, symptoms, or lung function in lung transplant recipients.

Cell type-specific and disease-associated eQTL in the human lung

Common genetic variants confer substantial risk for chronic lung diseases, including pulmonary fibrosis (PF). Defining the genetic control of gene expression in a cell-type-specific and context-dependent manner is critical for understanding the mechanisms through which genetic variation influences complex traits and disease pathobiology. To this end, we performed single-cell RNA-sequencing of lung tissue from 67 PF and 49 unaffected donors. Employing a pseudo-bulk approach, we mapped expression quantitative trait loci (eQTL) across 38 cell types, observing both shared and cell type-specific regulatory effects. Further, we identified disease-interaction eQTL and demonstrated that this class of associations is more likely to be cell-type specific and linked to cellular dysregulation in PF. Finally, we connected PF risk variants to their regulatory targets in disease-relevant cell types. These results indicate that cellular context determines the impact of genetic variation on gene expression, and implicates context-specific eQTL as key regulators of lung homeostasis and disease.

Pre-exposure Prophylaxis with Tixagevimab-cilgavimab did not Reduce Severity of COVID-19 in Lung Transplant Recipients with Breakthrough Infection

Lung transplant recipients (LTRs) have an increased risk of COVID-19-related morbidity and mortality. Tixagevimab-cilgavimab (tix-cil) is a long-acting monoclonal antibody combination granted Emergency Use Authorization approval by the US Food and Drug Administration for COVID-19 pre-exposure prophylaxis (PrEP) in immunocompromised patients. We sought to determine whether tix-cil 300-300 mg reduced the incidence and disease severity of severe acute respiratory syndrome coronavirus 2 infection in LTRs during the Omicron wave.

Methods

We performed a retrospective, single-center cohort study of LTRs who had received a COVID-19 diagnosis between December 2021 and August 2022. We compared baseline characteristics and clinical outcomes after COVID-19 between LTRs who received tix-cil PrEP and those who did not. We then conducted propensity-score matching based on baseline characteristics and therapeutic interventions and compared clinical outcomes between the 2 groups.

Results

Of 203 LTRs who received tix-cil PrEP and 343 who did not, 24 (11.8%) and 57 (16.6%), respectively, developed symptomatic COVID-19 (hazard ratio [HR], 0.669; 95% confidence interval [CI], 0.415-1.079; P = 0.099). The hospitalization rate of LTRs with COVID-19 during the Omicron wave trended lower in the tix-cil group than in the non-tix-cil group (20.8% versus 43.1%; HR, 0.430; 95% CI, 0.165-1.118; P = 0.083). In propensity-matched analyses, 17 LTRs who received tix-cil and 17 LTRs who did not had similar rates of hospitalization (HR, 0.468; 95% CI, 0.156-1.402; P = 0.175), intensive care unit admission (HR, 3.096; 95% CI, 0.322-29.771; P = 0.328), mechanical ventilation (HR, 1.958; 95% CI, 0.177-21.596; P = 0.583), and survival (HR, 1.015; 95% CI, 0.143-7.209; P = 0.988). COVID-19-related mortality was high in both propensity-score-matched groups (11.8%).

Conclusions

Breakthrough COVID-19 was common among LTRs despite tix-cil PrEP, possibly due to reduced efficacy of monoclonal antibodies against the Omicron variant. Tix-cil PrEP may reduce the incidence of COVID-19 in LTRs, but it did not reduce disease severity during the Omicron wave.

Loss of IGFBP2 mediates alveolar type 2 cell senescence and promotes lung fibrosis

Accumulation of senescent cells contributes to age-related diseases including idiopathic pulmonary fibrosis (IPF). Insulin-like growth factor binding proteins (IGFBPs) regulate many biological processes; however, the functional contributions of IGFBP2 in lung fibrosis remain largely unclear. Here, we report that intranasal delivery of recombinant IGFBP2 protects aged mice from weight loss and demonstrated antifibrotic effects after bleomycin lung injury. Notably, aged human-Igfbp2 transgenic mice reveal reduced senescence and senescent-associated secretory phenotype factors in alveolar epithelial type 2 (AEC2) cells and they ameliorated bleomycin-induced lung fibrosis. Finally, we demonstrate that IGFBP2 expression is significantly suppressed in AEC2 cells isolated from fibrotic lung regions of patients with IPF and/or pulmonary hypertension compared with patients with hypersensitivity pneumonitis and/or chronic obstructive pulmonary disease. Altogether, our study provides insights into how IGFBP2 regulates AEC2-cell-specific senescence and that restoring IGFBP2 levels in fibrotic lungs can prove effective for patients with IPF.

Antireflux surgery versus medical management of gastro-oesophageal reflux after lung transplantation

OBJECTIVES

Gastro-oesophageal reflux disease after lung transplantation may be associated with chronic lung allograft dysfunction. Aspiration may continue on medical management of reflux, but antireflux surgery potentially reduces all reflux. We compared outcomes between medical and surgical management of reflux in lung recipients.

METHODS

Lung recipients with an elevated DeMeester score (≥14.72) on post-transplant reflux testing between 2015 and 2020 were included. Patients were divided into 2 groups: group A (underwent surgery) and group B (medically managed). Endpoints were pulmonary function, allograft dysfunction-free survival and overall survival. Further analysis included subgroups: A1 (early surgery, <6 months) and A2 (late surgery, >6 months), and B1 (DeMeester <29.9) and B2 (DeMeester ≥30).

RESULTS

A total of 186 included subjects were divided into groups A [n = 46 (A1, n = 36; A2, n = 10)] and B [n = 140 (B1, n = 78; B2, n = 62)]. Compared to medically managed patients, patients who underwent surgery had a higher prevalence of hiatal hernia (P < 0.001) and a lower prevalence of oesophageal motility disorders (P = 0.036). Recipients who underwent surgery had superior pulmonary function at 5 years compared to group B (P < 0.05) and longer allograft dysfunction-free survival than subgroup B2 (P = 0.028). Furthermore, early surgery was associated with longer survival than late surgery (P = 0.021).

CONCLUSIONS

Antireflux surgery in recipients with reflux improved long-term allograft function, and early surgery showed a survival benefit. Allograft dysfunction-free survival of lung recipients who underwent surgery was significantly better than that of medically managed patients with DeMeester ≥30. We present an algorithm for appropriate selection of candidates for antireflux surgery after lung transplantation.

Hospitalized patients with irreversible lung injury from COVID-19 have higher morbidity but similar 1-year survival after lung transplant compared to hospitalized patients transplanted for restrictive lung disease

BACKGROUND

Hospitalized lung transplant (LT) recipients (LTRs) have higher post-LT morbidity and mortality than those who are well enough to wait for transplant at home. Outcomes after LT for COVID-19-associated acute respiratory distress syndrome (CARDS) may be even worse; thus, we compared post-LT outcomes between hospitalized LTRs transplanted for CARDS and those transplanted for restrictive lung disease (RLD).

METHODS

Between 2014 and 2021, hospitalized LTRs ≥18 years old with CARDS or RLD were included. Primary and secondary outcomes were 1-year post-LT survival and postoperative morbidity. For each patient in the CARDS group, an analysis of 1-to-1 matched patients from the RLD group was performed using logistic regression modeling.

RESULTS

Of 764 LTRs, 163 (21.3%) were hospitalized at the time of LT; 132 met the inclusion criteria: 11 (8.3%) were transplanted for CARDS and 121 (91.7%) for RLD. LTRs with CARDS were younger with longer pre-LT hospitalization stays and higher rates of pretransplant mechanical ventilation, dialysis, and ECMO as a bridge to transplant. A propensity-matched analysis demonstrated comparable rates of intrathoracic adhesions, posttransplant duration of mechanical ventilation, PGD3 at 72 hours, and delayed chest closure. Compared to LTRs with RLD, those with CARDS had significantly longer posttransplant hospital stays and a higher prevalence of ACR ≥A2 and DSA >2000 MFI, but comparable 1-year survival rates.

CONCLUSION

Even with careful selection, LT for patients with CARDS was associated with significant morbidity; however, 1-year survival of recipients with CARDS was comparable to that of matched hospitalized recipients with RLD.

Association Between Antibodies Against Lung Self-Antigens and Gastroesophageal Reflux in Lung Transplant Candidates

Gastroesophageal reflux (GER) and pretransplant antibodies against lung self-antigens (SAbs) collagen-V and/or k-alpha 1 tubulin are both independently associated with allograft dysfunction after lung transplantation (LTx). The role of GER in inducing lung injury and SAbs is unknown. We aimed to study the association between pre-LTx GER and SAbs. After IRB approval, we retrieved SAb assays conducted between 2015 and 2019 and collected 24 hour GER data for these patients. Patients were divided into 2 groups: no reflux (GER-) and pathologic reflux (GER+) to compare the prevalence of SAbs. Multivariate analysis was used to study the association between GER and SAbs in the whole cohort and in restrictive lung disease (RLD) and obstructive lung disease (OLD) subsets. Proximal esophageal reflux (PER) events ≥5 was considered abnormal. Patients (n = 134; 73 men) were divided into groups: GER- (54.5%, n = 73) and GER+ (45.5%, n = 61). The prevalence of GER was higher in the RLD than in the OLD subset (p < 0.001). The overall prevalence of SAbs was 53.7% (n = 72), higher in the GER+ than the GER- group (65.6% vs 43.8%, p = 0.012), but comparable between RLD and OLD subsets. Overall, SAbs were associated with GER (p = 0.012) and abnormal PER (p = 0.017). GER and abnormal PER increased the odds of SAbs in the RLD subset (OR [95% CI]: 2.825 [1.033-7.725], p = 0.040 and OR [95% CI]: 3.551 [1.271-9.925], p = 0.014, respectively) but not in the OLD subset. LTx candidates have a high prevalence of SAbs, which are significantly associated with GER and abnormal PER in patients with RLD.

Morbidity of antireflux surgery in lung transplant and matched nontransplant cohorts is comparable

BACKGROUND

Safety data on perioperative outcomes of laparoscopic antireflux surgery (LARS) after lung transplantation (LT) are lacking. We compared the 30-day readmission rate and short-term morbidity after LARS between LT recipients and matched nontransplant (NT) controls.

METHODS

Adult patients who underwent LARS between January 1, 2015, and October 31, 2021, were included. The participants were divided into two groups: LT recipients and NT controls. First, we compared 30-day readmission rates after LARS between the LT and NT cohorts. Next, we compared 30-day morbidity after LARS between the LT cohort and a 1-to-2 propensity score-matched NT cohort.

RESULTS

A total of 1328 patients (55 LT recipients and 1273 NT controls) were included. The post-LARS 30-day readmission rate was higher in LT recipients than in the overall NT controls (14.5% vs. 2.8%, p < 0.001). Compared to matched NT controls, LT recipients had a lower prevalence of paraesophageal hernia, a smaller median hernia size, and higher peristaltic vigor. Also compared to the matched NT controls, the LT recipients had a lower median operative time but a longer median length of hospital stay. The proportion of patients with a post-LARS event within 30 postoperative days was comparable between the LT and matched NT cohorts (21.8% vs 14.5%, p = 0.24).

CONCLUSIONS

Despite a higher perceived risk of comorbidity burden, LT recipients and matched NT controls had similar rates of post-LARS 30-day morbidity at our large-volume center with expertise in transplant and foregut surgery. LARS after LT is safe.

Incidentally Detected Malignancies in Lung Explants

Introduction: Incidentally detected malignancies in lung explants portend risk of early cancer recurrence and metastases with posttransplant immunosuppression. We present a series of lung transplant recipients with previously unverified malignancies in native lung explants. Design: We reviewed the histopathology, radiographic imaging, and management of lung explant malignancies at our institution over 10 years (2011-2020). Endpoints were survival and allograft rejection. Results: An explant malignancy was found in 1.3% (11/855) of lung transplant recipients (6 [55%] men; median age 68 years; 6 [55%] ex-smokers [median pack-years, 25]). Nine (82%) were adenocarcinoma, 1 (9%) was squamous cell carcinoma (SCC), and 1 (9%) was follicular lymphoma. Three patients (27%) had multifocal involvement (≥3 lobes), 4 (36%) had nodal involvement, and the median (range) tumor size was 2.7 (0.4-19) cm. The median interval between last imaging and transplant was 58 (29-144) days. Mycophenolate mofetil was discontinued or reduced in all; everolimus was used in 2 patients, and cisplatin-pemetrexed chemotherapy was used in 2 patients. The prevalence of acute cellular rejection and chronic rejection was 27% and 9%, respectively. Lung recipients with cancer had significantly lower survival than those without (36.4% vs 67.3%, p = 0.002); median survival was 27 (17, 65) months in 4 recipients who were alive and cancer-free at the end of the study period. Conclusions: Unidentified malignancies, commonly adenocarcinoma, can be detected in explanted native lungs. Pneumonectomy may be curative in SCC, lymphoproliferative disorders, and stage I adenocarcinoma. Modulating immunosuppression to prevent allograft rejection and tumor proliferation is warranted.

Unravelling a novel, promising and convenient tool for differential diagnosis of delayed puberty: GnRHa-stimulated inhibin B (GnRH-iB)

BACKGROUND

Etiological diagnosis of delayed puberty is difficult. Despite availability of various basal and stimulation tests differentiation between constitutional delay in puberty and hypogonadotropic hypogonadism is still challenging.

OBJECTIVE

To elucidate the role of GnRH agonist-stimulated inhibin B (GnRH-iB) for the differential diagnosis of delayed puberty.

STUDY DESIGN

Participants were recruited into "exploratory cohort" (n = 39) and "validation cohort" (n = 16). "Exploratory cohort" included children with spontaneous puberty and patients with hypogonadotropic hypogonadism. "Validation cohort" constituted children who presented with delayed puberty.

INTERVENTION AND OUTCOME

GnRHa (Triptorelin) stimulation test along with measurement of inhibin B level at 24 h after GnRHa injection was performed in all the study participants. Cut-offs for GnRH-iB were derived from the "exploratory cohort". These cut-offs were applied to the "validation cohort". Basal LH, basal inhibin B(INH-B), GnRHa-stimulated LH at 4 h (GnRH-LH) and GnRH-iB were evaluated for the prediction of onset of puberty on prospective follow-up.

RESULTS

GnRH-iB at a cut-off value of 113.5 pg/ml in boys and 72.6 pg/ml in girls had 100% sensitivity and specificity for the documentation of puberty. In the "validation cohort" basal LH, basal INH-B, GnRH-LH, and GnRH-iB had a diagnostic accuracy of 68.75%, 81.25%, 68.75% and 93.75% respectively, for the prediction of onset of puberty. Basal LH, basal INH-B and GnRH-LH used alone or in combination were inferior to GnRH-iB used alone.

CONCLUSION

GnRHa-stimulated inhibin B (GnRH-iB) is a convenient and easily employable test for the differentiation of constitutional delay in puberty from hypogonadotropic hypogonadism.

CTRI REGISTRATION NO

CTRI/2019/10/021570.

Exploring optimal multimode vibronic pathways in singlet fission of azaborine analogues of perylene

The development of new singlet fission chromophores is a vibrant area of research to explore the possibility of efficient photovoltaic devices. Using high-level ab-initio density matrix renormalization group calculations, we present a systematic analysis of BN-doped perylenes for their potential application as singlet fission candidates. Four singlet fission chromophores are identified considering the monomer-based properties and their excitonic characters are further analyzed in a dimer configuration optimized in a six-dimensional space for local maxima of fission rates. Furthermore, a multistate multimode vibronic Hamiltonian is employed to identify intra- and interstate vibrational pathways for excitation energy modulation. Several photophysical properties such as Davydov splitting, activation energy and vibronic admixture of multiexcitonic and charge-transfer states are calculated for physically accessible dimers. The optimal dimer packing results in appropriate vibrational relaxation of singlet fission states and promotes significant population transfer which would be more attenuated without such couplings. This work not only identifies potential singlet fission systems with favorable electronic properties but also highlights the sensitivity of dimer packings with respect to the substitution patterns in singlet fission chromophores.

Universal Lifelong Fungal Prophylaxis and Risk of Coccidioidomycosis in Lung Transplant Recipients Living in an Endemic Area

BACKGROUND

Lung transplant recipients residing in the endemic region are vulnerable to severe morbidity and mortality from Coccidioides. As infection risk persists beyond the first posttransplant year, investigations evaluating extended prophylaxis durations are needed. The purpose of this study is to assess the incidence of coccidioidomycosis among lung transplant recipients receiving universal lifelong azole antifungal prophylaxis.

METHODS

Patients receiving transplants from 2013-2018 and initiated on azole antifungal prophylaxis at a lung transplant center in Arizona were included and followed through 2019 or until death, second transplant, or loss to follow-up. Recipients who died or received treatment for coccidioidomycosis during the transplant admission, or who had received a previous transplant, were excluded. The primary outcome was proven or probable coccidioidomycosis with new asymptomatic seropositivity assessed secondarily.

RESULTS

A total of 493 lung transplant recipients were included, with 82% initiated on itraconazole prophylaxis, 9.3% on voriconazole, and 8.5% on posaconazole. Mean age at transplant was 62 years, 77% were diabetic, and 8% were seropositive for Coccidioides pretransplant. After a median follow-up of 31 months, 1 proven infection and 1 case of new asymptomatic seropositivity (1/493 each, 0.2% incidence) occurred during the study period. The single coccidioidomycosis case occurred 5 years posttransplant in a patient who had azole prophylaxis stopped several months prior. Although within-class switches were common throughout the study period, permanent discontinuation of azole prophylaxis was rare (1.4% at end of follow-up).

CONCLUSIONS

Universal lifelong azole prophylaxis was associated with a low rate of coccidioidomycosis among lung transplant recipients residing in endemic regions.

Management of the Potential Lung Donor

The use of donor management protocols has significantly improved recovery rates; however, the inherent instability of lungs after death results in low utilization rates of potential donor lungs. Donor lungs are susceptible to direct trauma, aspiration, neurogenic edema, ventilator-associated barotrauma, and ventilator-associated pneumonia. After irreversible brain injury and determination of futility of care, the goal of medical management of the donor shifts to maintaining hemodynamic stability and maximizing the likelihood of successful organ recovery.

Lung Transplantation for COVID-19-Induced Respiratory Failure: Single-Center Case Series

Purpose

Prior to the COVID-19 (C19) pandemic, adult respiratory distress syndrome (ARDS) was an unusual indication for lung transplant (LT); thus, short- and long-term outcomes data are lacking. As the pandemic continues, there is an increased need for post-LT data. Thus, we report our single-center experience transplanting 11 patients for C19 ARDS.

Methods

We conducted a chart review of LT recipients (LTRs) transplanted for C19 ARDS between 8/1/21 and 7/31/21. Descriptive statistics were used.

Results

Most LTRs were male (82%, n=9). The median age at LT, body mass index, and lung allocation score were 47 (43, 54) years, 28.9 (26, 30) kg/m2, and 84.5 (60, 88), respectively. The median interval from initial hospitalization to listing and listing to LT was 119 (97, 124) and 5 (4, 11) days, respectively. Pretransplant COVID-related morbidities included venous thromboembolism (55%, n=6), hemorrhage requiring transfusion (36%, n=4), pneumothorax (55%, n=6), bacterial pneumonia (82%, n=9), bacteremia (45%, n=5), fungemia (36%, n=4), renal failure requiring renal replacement therapy (RRT; 9%, n=1), cerebrovascular event (9%, n=1), and musculoskeletal weakness (100%, n=11). Most patients required mechanical ventilation (91%, n=10), and 55% (n=6) were intubated at the time of LT. Furthermore, most patients required ECMO support (73%, n=8) and 36% (n=4) were on ECMO at the time of LT. Intraoperatively, 64% (n=7) of patients required cardiopulmonary bypass, 73% (n=8) had severe intrathoracic adhesions, 73% (n=8) had delayed chest closure, and 18% (n=2) had an unexpected return to the operating room. Prevalence of primary graft dysfunction grade 2 or 3 at 72 hours was high (91%, n=10), median duration of mechanical ventilation after LT was 10 (6, 19) days, but no one required ECMO rescue. To date, 10 (91%) LTRs have been discharged, and 2 (20%) have been readmitted within 30 days; the median post-LT hospital stay was 18 (14, 24) days; all discharged LTRs required acute rehabilitation for a median of 17.5 (14, 23) days. Ten LTRs (91%) at a median of 208 (167, 245) days post-LT; 1 LTR died 344 days post-LT of treatment-refractory allograft failure due to aspiration and antibody-mediated rejection.

Conclusion

Despite pre-LT critical illness, intraoperative challenges, and prolonged post-LT recovery, LT appears feasible for carefully selected patients with irreversible C19 ARDS.

A Comparison of Short-Term Morbidity and Mortality Among Inpatient Lung Transplant Recipients Transplanted for COVID-19 and Other Restrictive Lung Diseases

Purpose

Patients with respiratory failure (RF) who are hospitalized at the time of lung transplant (LTx) have higher post-LTx morbidity and mortality than those who are well enough to remain at home. Complications may be even worse in patients transplanted for COVID-19 (C19), as they are commonly critically ill having endured prolonged mechanical ventilation, ECMO support, myopathy, malnutrition, and superimposed infections. In a retrospective cohort study, we compared inpatient lung transplant recipients (LTxRs) transplanted for C19 vs. other underlying restrictive lung diseases (RLDs)

Methods

After IRB approval, patients who underwent inpatient LTx between 1/1/2014 and 8/31/2021 were categorized by indication: C19 or RLD. We excluded LTxRs <18 years old, a primary indication for LTx other than UNOS disease group D, and redo LTx. Primary outcomes were postoperative morbidity and 90-day survival.

Results

Out of 163 inpatient LTxRs, 141 met inclusion criteria: 11 (7.8%) with C19 and 130 (92.2%) with RLD. LTxRs with C19 were younger, had a longer pre-LTx hospital stay, and more likely needed pre-LTx mechanical ventilation and ECMO support. LTxRs with C19 were also more likely to have severe adhesions intraoperatively and their chest was more commonly left open after LTx due to a perceived risk of ongoing bleeding. In addition, LTxRs with C19 had a higher prevalence of PGD3 at 72 hours and longer post-LTx hospital stays and trended toward longer post-LTx mechanical ventilation and need for inpatient rehabilitation. The 2 groups had similar 90-day survival (C19, 100% vs. RLD, 95.4%, p=0.472), however, LTxRs with C19 had a higher incidence of acute cellular rejection and DSA production (>2,000 MFI) within 6 months of transplant.

Conclusion

LTxRs with C19 are typically sicker and have more post-LTx complications than LTxRs with RLD hospitalized at the time of LTx. However, 90-day survival is comparable and high in both groups. Long-term follow-up is needed.

Novel role for tumor suppressor gene, liver kinase B1, in epithelial-mesenchymal transition leading to chronic lung allograft dysfunction

Epithelial-mesenchymal transition (EMT) has been implicated to play a role in chronic lung allograft dysfunction (CLAD). Liver kinase B1 (LKB1), a tumor suppressor gene, can regulate EMT. However, its role in CLAD development following lung transplantation remains unknown. Using qRT-PCR, biopsies from lung transplant recipients with bronchiolitis obliterans syndrome (BOS) demonstrated significant downregulation of LKB1 (p = .0001), compared to stable biopsies. To determine the role of LKB1 in EMT development, we analyzed EMT in human bronchial epithelial cell line BEAS-2B. Knockdown of LKB1 by siRNA significantly dysregulated mesenchymal markers expression in BEAS-2B cells. Following incubation of human primary bronchial epithelial cell or BEAS-2B cells with exosomes isolated from BOS or stable lung transplant recipients, LKB1 expression was inhibited when incubated with BOS-exosome. Incubation with BOS-exosomes also decreased LKB1 expression and induced EMT markers in air-liquid interface culture method. Our results provide novel evidence that exosomes released from transplanted lungs undergoing chronic rejection are associated with inactivated tumor suppressor gene LKB1 and this loss induces EMT leading to the pathogenesis of CLAD following human lung transplantation.

Lung Transplant Candidates With Pretransplant Gastroesophageal Reflux and Antibodies to Lung Self-antigens Have Shorter CLAD-free Survival After Transplant

Pre–lung transplant (LTx) gastroesophageal reflux (GER) and circulating antibodies against the lung self-antigens (SAbs) collagen V and K-alpha-1 tubulin may predispose recipients to chronic lung allograft dysfunction (CLAD). We aimed to study the association of pre-LTx GER or pre-LTx SAbs with CLAD.

Current trends in candidate selection, contraindications, and indications for lung transplantation

Lung transplantation is an established treatment option that can improve quality of life and prolong survival for select patients diagnosed with end-stage lung disease. Given the gaps in organ donation and failures to make effective use of available organs, careful selection of candidates for lung transplant remains one of the most important considerations of the transplant community. Toward this end, we briefly reviewed recent trends in pretransplant evaluation, candidate selection, organ allocation, and organ preservation techniques. Since the latest consensus statement regarding appropriate selection of lung transplant candidates, many advances in the science and practice of lung transplantation have emerged and influenced our perspective of ‘contraindications’ to transplant. These advances have made it increasingly possible to pursue lung transplant in patients with risk factors for decreased survival—namely, older recipient age, increased body mass index, previous chest surgery, poorer nutritional status, and presence of chronic infection, cardiovascular disease, or extrapulmonary comorbid conditions. Therefore, we reviewed the updated evidence demonstrating the prognostic impact of these risk factors in lung transplant recipients. Lastly, we reviewed the salient evidence for current trends in disease-specific indications for lung transplantation, such as chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, cystic fibrosis, emphysema due to alpha-1 antitrypsin deficiency, and pulmonary arterial hypertension, among other less common end-stage diseases. Overall, lung transplant remains an exciting field with considerable hope for patients as they experience remarkable improvements in quality of life and survival in the modern era.

Towards multistate multimode landscapes in singlet fission of pentacene: the dual role of charge-transfer states

Singlet fission duplicates triplet excitons for improving light harvesting efficiency. The presence of the interaction between electronic and nuclear degrees of freedom complicates the interpretation of correlated triplet pairs. We report a quantum chemistry study on the significance and subtleties of multistate and multimode pathways in forming triplet pair states of the pentacene dimer through a six-state vibronic-coupling Hamiltonian derived from many-electron adiabatic wavefunctions of an ab initio density matrix renormalization group. The resulting spin values of the singlet manifolds on each pentacene center are computed, and the varying spin nature can be distinguished clearly with respect to dimer stacking and vibronic progression. Our monomer spin assignments reveal the coexistence of both lower-lying weak and higher-lying strong charge transfer states which interact vibronically with the triplet pair state, providing important implications for its generation and separation occurring in vibronic regions. This work conveys the importance of the many-electron process requiring close low-lying singlet manifolds to determine the subtle fission details, and represents an important step for understanding vibronically resolved spin states and conversions underlying efficient singlet fission.

Outcomes after lung transplantation in recipients aged 70 years or older

BACKGROUND

The proportion of lung transplant (LTx) recipients older than 70 years is increasing, thus we assessed long-term survival after LTx in this cohort relative to younger counterparts.

PATIENTS AND METHODS

We retrospectively reviewed charts of patients who underwent LTx between 2012 and 2016 at our center and divided patients by age: group A (<65 years), B (65-69 years), and C (≥70 years). Survival statistics were evaluated using the Kaplan-Meier method and Cox regression.

RESULTS

The study included 375 LTx recipients: 221 (58.9%) in group A, 109 (29.1%) in group B, and 45 (12.0%) in group C. Group C was mostly men (37/45 [82.2%]; P = 0.003) and had the highest mean serum creatinine at listing (P = 0.02). Survival at 1, 3, and 5 years after transplant in group A (93.2%, 70.1%, 58.8%) was significantly higher than group B (83.5%, 59.6%, 44.0%; P = 0.005, 0.028, 0.006, log-rank test) and was similar to group C (86.7%, 64.4%, 57.8%), although trended higher at 1 year (P = 0.139, 0.274, 0.489, log-rank test). Groups B and C had comparable survival at all time points.

CONCLUSIONS

Although survival decreased after age 65, long-term survival was comparable between LTx recipients aged 65-69 years and recipients ≥70 years.

Outcomes of nontuberculous mycobacteria isolation among lung transplant recipients: A matched case-control with retrospective cohort study

DISCLAIMER

In an effort to expedite the publication of articles , AJHP is posting manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time.

PURPOSE

Lung transplant recipients are at increased risk for acquiring nontuberculous mycobacteria (NTM), but the clinical significance of NTM isolation, particularly among patients not meeting guideline-endorsed diagnostic criteria for NTM pulmonary disease, is unclear.

METHODS

A case-control study of lung transplant recipients with culture-positive NTM infections treated at a large transplant center during a 7-year period (2013-2019) was performed.

RESULTS

Twenty-nine cases were matched 1:2 to non-NTM controls. The median time to NTM isolation was 10.7 months post transplant. Only 34.5% of all cases, and half of treated cases, met diagnostic criteria for NTM pulmonary infection. All-cause mortality at 12 months was numerically higher among NTM cases versus controls (20.7% vs 8.6%, P = 0.169); however, no deaths were attributed to NTM. No increase in the 12-month rate of acute rejection was observed (27.6% vs 36.2%, P = 0.477). Recent augmented immunosuppression was associated with increased odds of NTM isolation, while azithromycin prophylaxis was associated with reduced odds of isolation and was not associated with macrolide resistance. Both adverse events and actual or potential drug-drug interactions occurred in more than 90% of treated cases; these events included ocular toxicity, hearing loss, and supratherapeutic calcineurin inhibitor concentrations. Eight of the 14 treated cases (57.1%) required early antibiotic discontinuation due to adverse events or drug-drug interactions.

CONCLUSION

Among lung transplant recipients, most patients with NTM isolation did not meet guideline criteria for infection and had outcomes similar to non‒NTM-infected patients, which may reflect transient lung colonization by NTM rather than true disease. As adverse events are common with NTM therapy, limiting unnecessary antibiotic treatment represents an area for future antimicrobial stewardship efforts.