Vascular endothelial-derived SPARCL1 exacerbates viral pneumonia through pro-inflammatory macrophage activation.

Inflammation induced by lung infection is a double-edged sword, moderating both anti-viral and immune pathogenesis effects; the mechanism of the latter is not fully understood. Previous studies suggest the vasculature is involved in tissue injury. Here, we report that expression of Sparcl1, a secreted matricellular protein, is upregulated in pulmonary capillary endothelial cells (EC) during influenza-induced lung injury. Endothelial overexpression of SPARCL1 promotes detrimental lung inflammation, with SPARCL1 inducing 'M1-like' macrophages and related pro-inflammatory cytokines, while SPARCL1 deletion alleviates these effects. Mechanistically, SPARCL1 functions through TLR4 on macrophages in vitro, while TLR4 inhibition in vivo ameliorates excessive inflammation caused by endothelial Sparcl1 overexpression. Finally, SPARCL1 expression is increased in lung ECs from COVID-19 patients when compared with healthy donors, while fatal COVID-19 correlates with higher circulating SPARCL1 protein levels in the plasma. Our results thus implicate SPARCL1 as a potential prognosis biomarker for deadly COVID-19 pneumonia and as a therapeutic target for taming hyperinflammation in pneumonia.

Inflammatory and tissue injury marker dynamics in pediatric acute respiratory distress syndrome.

BACKGROUNDThe molecular signature of pediatric acute respiratory distress syndrome (ARDS) is poorly described, and the degree to which hyperinflammation or specific tissue injury contributes to outcomes is unknown. Therefore, we profiled inflammation and tissue injury dynamics over the first 7 days of ARDS, and associated specific biomarkers with mortality, persistent ARDS, and persistent multiple organ dysfunction syndrome (MODS).METHODSIn a single-center prospective cohort of intubated pediatric patients with ARDS, we collected plasma on days 0, 3, and 7. Nineteen biomarkers reflecting inflammation, tissue injury, and damage-associated molecular patterns (DAMPs) were measured. We assessed the relationship between biomarkers and trajectories with mortality, persistent ARDS, or persistent MODS using multivariable mixed effect models.RESULTSIn 279 patients (64 [23%] nonsurvivors), hyperinflammatory cytokines, tissue injury markers, and DAMPs were higher in nonsurvivors. Survivors and nonsurvivors showed different biomarker trajectories. IL-1α, soluble tumor necrosis factor receptor 1, angiopoietin 2 (ANG2), and surfactant protein D increased in nonsurvivors, while DAMPs remained persistently elevated. ANG2 and procollagen type III N-terminal peptide were associated with persistent ARDS, whereas multiple cytokines, tissue injury markers, and DAMPs were associated with persistent MODS. Corticosteroid use did not impact the association of biomarker levels or trajectory with mortality.CONCLUSIONSPediatric ARDS survivors and nonsurvivors had distinct biomarker trajectories, with cytokines, endothelial and alveolar epithelial injury, and DAMPs elevated in nonsurvivors. Mortality markers overlapped with markers associated with persistent MODS, rather than persistent ARDS.FUNDINGNIH (K23HL-136688, R01-HL148054).

Characterizing proximity and transfers of deceased organ donors to donor care units in the United States.

Some United States organ procurement organizations transfer deceased organ donors to donor care units (DCUs) for recovery procedures. We used Organ Procurement and Transplantation Network data, from April 2017 to June 2021, to describe the proximity of adult deceased donors after brain death to DCUs and understand the impact of donor service area (DSA) boundaries on transfer efficiency. Among 19 109 donors (56.1% of the cohort) in 25 DSAs with DCUs, a majority (14 593 [76.4%]) were in hospitals within a 2-hour drive. In areas with DCUs detectable in the study data set, a minority of donors (3582 of 11 532 [31.1%]) were transferred to a DCU; transfer rates varied between DSAs (median, 27.7%, range, 4.0%-96.5%). Median hospital-to-DCU driving times were not meaningfully shorter among transferred donors (50 vs 51 minutes for not transferred, P < .001). When DSA boundaries were ignored, 3241 cohort donors (9.5%) without current DCU access were managed in hospitals within 2 hours of a DCU and thus potentially eligible for transfer. In summary, approximately half of United States deceased donors after brain death are managed in hospitals in DSAs with a DCU. Transfer of donors between DSAs may increase DCU utilization and improve system efficiency.

Benefits of Aeroallergen Testing on Oral Corticosteroid Bursts in Adults with Asthma.

BACKGROUND: Aeroallergen testing can improve precision care for persistent asthma and is recommended by the U.S. clinical guidelines. How testing benefits diverse populations of adults with asthma, and the importance of the testing modality used, are not fully understood. OBJECTIVE: We sought to evaluate whether receipt of aeroallergen testing was associated with a reduction in oral corticosteroid (OCS) bursts. METHODS: We used electronic health record data to conduct a retrospective, observational cohort study of adults with asthma who were prescribed an inhaled corticosteroid and had an Allergy/Immunology visit in a large health system between 1/1/2017-6/30/2022. Negative binomial regression models were used to evaluate whether OCS bursts in the 12-month period after an initial visit were reduced for patients who received aeroallergen testing. We also measured differences in benefit after excluding patients with chronic obstructive pulmonary disease (COPD) and smoking histories, and whether testing receipt was via skin prick or serum. RESULTS: 668/1,383 (48.3%) patients received testing. Receipt of testing was not associated with fewer bursts in all patients (incidence rate ratio (IRR)=0.83 versus no testing, p=0.059), but it was among never smokers without COPD (417/844 tested, IRR=0.68, p=0.004). The receipt of skin testing was associated with fewer bursts in all patients (418/1,383 tested, IRR=0.77, p=0.02) and among never smokers without COPD (283/844 tested, IRR=0.59 versus no testing, p=0.001). CONCLUSION: Guideline-concordant aeroallergen testing in the context of Allergy/Immunology care was associated with clinical benefit in a real-life, diverse cohort of adults with asthma. This benefit varied according to patient comorbidities and the testing modality.

Comparison of Administration of 8-Milligram and 4-Milligram Intranasal Naloxone by Law Enforcement During Response to Suspected Opioid Overdose - New York, March 2022-August 2023.

In 2021, an 8-mg intranasal naloxone product was approved by the Food and Drug Administration; however, no studies have examined outcomes among persons who receive the 8-mg naloxone product and those who receive the usual 4-mg product. During March 2022-August 2023, New York State Department of Health (NYSDOH) supplied some New York State Police (NYSP) troops with 8-mg intranasal naloxone; other troops continued to receive 4-mg intranasal naloxone to treat suspected opioid overdose. NYSP submitted detailed reports to NYSDOH when naloxone was administered. No significant differences were observed in survival, mean number of naloxone doses administered, prevalence of most postnaloxone signs and symptoms, postnaloxone anger or combativeness, or hospital transport refusal among 4-mg and 8-mg intranasal naloxone recipients; however, persons who received the 8-mg intranasal naloxone product had 2.51 times the risk for opioid withdrawal signs and symptoms, including vomiting, than did those who received the 4-mg intranasal naloxone product (95% CI = 1.51-4.18). This initial study suggests no benefits to law enforcement administration of higher-dose naloxone were identified; more research is needed to guide public health agencies in considering whether 8-mg intranasal naloxone confers additional benefits for community organizations.

Scoring donor lungs for graft failure risk: The Lung Donor Risk Index (LDRI).

Lung transplantation lags behind other solid organ transplants in donor lung utilization due, in part, to uncertainty regarding donor quality. We sought to develop an easy-to-use donor risk metric that, unlike existing metrics, accounts for a rich set of donor factors. Our study population consisted of n = 26 549 adult lung transplant recipients abstracted from the United Network for Organ Sharing Standard Transplant Analysis and Research file. We used Cox regression to model graft failure (GF; earliest of death or retransplant) risk based on donor and transplant factors, adjusting for recipient factors. We then derived and validated a Lung Donor Risk Index (LDRI) and developed a pertinent online application (https://shiny.pmacs.upenn.edu/LDRI_Calculator/). We found 12 donor/transplant factors that were independently predictive of GF: age, race, insulin-dependent diabetes, the difference between donor and recipient height, smoking, cocaine use, cytomegalovirus seropositivity, creatinine, human leukocyte antigen (HLA) mismatch, ischemia time, and donation after circulatory death. Validation showed the LDRI to have GF risk discrimination that was reasonable (C = 0.61) and higher than any of its predecessors. The LDRI is intended for use by transplant centers, organ procurement organizations, and regulatory agencies and to benefit patients in decision-making. Unlike its predecessors, the proposed LDRI could gain wide acceptance because of its granularity and similarity to the Kidney Donor Risk Index.

Provider beliefs and practices regarding the management of obesity in lung transplant recipients.

Obesity at the time of lung transplant is associated with decreased survival. How providers manage obesity after lung transplantation is unknown. We performed an international survey of lung transplant providers to assess beliefs and practices regarding post-transplant obesity management. Eighty-one providers initiated the survey and 73 (90%) completed the full survey. Respondents were primarily North American-based pulmonary physicians. Nearly all providers believe treating obesity improves quality of life (99%) and survival (95%) after lung transplantation, but that only 41% of patients attempting weight loss are successful. While respondents nearly always recommend diet (96%), exercise (92%), and dietician consultation (89%), they less frequently recommend prescription weight loss medications (29%) or bariatric surgery (11%). Lung transplant providers are motivated to treat obesity in transplant recipients. However, there is a gap between general obesity treatment guidelines and lung transplant practice. Additional training, education, and trials in this population could address this gap.

Lung transplant outcomes after acute respiratory distress syndrome requiring extracorporeal life support: Lessons from the COVID-19 pandemic.

OBJECTIVE: Lung transplant for acute respiratory distress syndrome in patients supported with extracorporeal membrane oxygenation was rare before 2020, but was rapidly adopted to rescue patients with COVID-19 with lung failure. This study aims to compare the outcomes of patients who underwent lung transplant for COVID-associated acute respiratory distress syndrome and non-COVID acute respiratory distress syndrome, and to assess the impact of type and duration of extracorporeal membrane oxygenation support on survival. METHODS: Using the United Network for Organ Sharing database, we identified 311 patients with acute respiratory distress syndrome who underwent lung transplant from 2007 to 2022 and performed a retrospective analysis of the patients who required extracorporeal membrane oxygenation preoperatively, stratified by COVID-associated acute respiratory distress syndrome and non-COVID acute respiratory distress syndrome listing diagnoses. The primary outcome was 1-year survival. Secondary outcomes included the effect of type and duration of extracorporeal membrane oxygenation on survival. RESULTS: During the study period, 236 patients with acute respiratory distress syndrome and preoperative extracorporeal membrane oxygenation underwent lung transplant; 181 patients had a listing diagnosis of COVID-associated acute respiratory distress syndrome (77%), and 55 patients had a listing diagnosis of non-COVID acute respiratory distress syndrome (23%). Patients with COVID-associated acute respiratory distress syndrome were older, were more likely to be female, had higher body mass index, and spent longer on the waitlist (all P < .02) than patients with non-COVID acute respiratory distress syndrome. The 2 groups had similar 1-year survival (85.8% vs 81.1%, P = .2) with no differences in postoperative complications. Patients with COVID-associated acute respiratory distress syndrome required longer times on extracorporeal membrane oxygenation pretransplant (P = .02), but duration of extracorporeal membrane oxygenation support was not a predictor of 1-year survival (P = .2). CONCLUSIONS: Despite prolonged periods of pretransplant extracorporeal membrane oxygenation support, selected patients with acute respiratory distress syndrome can undergo lung transplant safely with acceptable short-term outcomes. Appropriate selection criteria and long-term implications require further analysis.

Nonlinear associations between computed tomography-measures of adiposity and long pentraxin-3 in the Multi-Ethnic Study of Atherosclerosis.

Objective: Long pentraxin-3 (PTX-3) is an acute phase protein associated with cardiovascular disease, lung injury, and mortality. We evaluated the association between computed tomography (CT)-measurements of adipose tissue and plasma levels of PTX-3. Methods: We performed a cross-sectional analysis of community-dwelling adults enrolled in the multi-center Multiethnic Study of Atherosclerosis who underwent cardiac or abdominal CT and had available PTX-3 measurements. Results: There was a U-shaped association between pericardial adipose tissue volume (PAT), abdominal visceral adipose tissue area (VAT), hepatic attenuation, and PTX-3 levels, with extremes of adiposity associated with greater PTX-3 levels. Using multivariable-adjusted piecewise regression models, among participants with low PAT, every 1% increase in PAT volume was associated with a 13.8% decrease in PTX-3 (95% confidence interval [CI] -21.6 to -6.0); among participants with high PAT, every 1% increase in PAT volume was associated with a 6.0% increase in PTX-3 (95% CI -0.4 to 12.5). Results were similar for abdominal VAT and hepatic attenuation. Conclusions: In a cohort of community-dwelling adults, we demonstrated a "U-shaped" association between pericardial, abdominal visceral, and hepatic adiposity with PTX3 levels, suggesting that extreme adiposity is associated with greater circulating levels of PTX3. Further work is required to identify the mechanisms linking adiposity and PTX-3.

Development and validation of primary graft dysfunction predictive algorithm for lung transplant candidates.

BACKGROUND: Primary graft dysfunction (PGD) is the leading cause of early morbidity and mortality after lung transplantation. Accurate prediction of PGD risk could inform donor approaches and perioperative care planning. We sought to develop a clinically useful, generalizable PGD prediction model to aid in transplant decision-making. METHODS: We derived a predictive model in a prospective cohort study of subjects from 2012 to 2018, followed by a single-center external validation. We used regularized (lasso) logistic regression to evaluate the predictive ability of clinically available PGD predictors and developed a user interface for clinical application. Using decision curve analysis, we quantified the net benefit of the model across a range of PGD risk thresholds and assessed model calibration and discrimination. RESULTS: The PGD predictive model included distance from donor hospital to recipient transplant center, recipient age, predicted total lung capacity, lung allocation score (LAS), body mass index, pulmonary artery mean pressure, sex, and indication for transplant; donor age, sex, mechanism of death, and donor smoking status; and interaction terms for LAS and donor distance. The interface allows for real-time assessment of PGD risk for any donor/recipient combination. The model offers decision-making net benefit in the PGD risk range of 10% to 75% in the derivation centers and 2% to 10% in the validation cohort, a range incorporating the incidence in that cohort. CONCLUSION: We developed a clinically useful PGD predictive algorithm across a range of PGD risk thresholds to support transplant decision-making, posttransplant care, and enrich samples for PGD treatment trials.

The Impact of Donor Smoking on Primary Graft Dysfunction and Mortality after Lung Transplantation.

Rationale: Primary graft dysfunction (PGD) is the leading cause of early morbidity and mortality after lung transplantation. Prior studies implicated proxy-defined donor smoking as a risk factor for PGD and mortality. Objectives: We aimed to more accurately assess the impact of donor smoke exposure on PGD and mortality using quantitative smoke exposure biomarkers. Methods: We performed a multicenter prospective cohort study of lung transplant recipients enrolled in the Lung Transplant Outcomes Group cohort between 2012 and 2018. PGD was defined as grade 3 at 48 or 72 hours after lung reperfusion. Donor smoking was defined using accepted thresholds of urinary biomarkers of nicotine exposure (cotinine) and tobacco-specific nitrosamine (4-[methylnitrosamino]-1-[3-pyridyl]-1-butanol [NNAL]) in addition to clinical history. The donor smoking-PGD association was assessed using logistic regression, and survival analysis was performed using inverse probability of exposure weighting according to smoking category. Measurements and Main Results: Active donor smoking prevalence varied by definition, with 34-43% based on urinary cotinine, 28% by urinary NNAL, and 37% by clinical documentation. The standardized risk of PGD associated with active donor smoking was higher across all definitions, with an absolute risk increase of 11.5% (95% confidence interval [CI], 3.8% to 19.2%) by urinary cotinine, 5.7% (95% CI, -3.4% to 14.9%) by urinary NNAL, and 6.5% (95% CI, -2.8% to 15.8%) defined clinically. Donor smoking was not associated with differential post-lung transplant survival using any definition. Conclusions: Donor smoking associates with a modest increase in PGD risk but not with increased recipient mortality. Use of lungs from smokers is likely safe and may increase lung donor availability. Clinical trial registered with www.clinicaltrials.gov (NCT00552357).

MICB Genomic Variant Is Associated with NKG2D-mediated Acute Lung Injury and Death.

Rationale: Acute lung injury (ALI) carries a high risk of mortality but has no established pharmacologic therapy. We previously found that experimental ALI occurs through natural killer (NK) cell NKG2D receptor activation and that the cognate human ligand, MICB, was associated with ALI after transplantation. Objectives: To investigate the association of a common missense variant, MICBG406A, with ALI. Methods: We assessed MICBG406A genotypes within two multicenter observational study cohorts at risk for ALI: primary graft dysfunction (N = 619) and acute respiratory distress syndrome (N = 1,376). Variant protein functional effects were determined in cultured and ex vivo human samples. Measurements and Main Results: Recipients of MICBG406A-homozygous allografts had an 11.1% absolute risk reduction (95% confidence interval [CI], 3.2-19.4%) for severe primary graft dysfunction after lung transplantation and reduced risk for allograft failure (hazard ratio, 0.36; 95% CI, 0.13-0.98). In participants with sepsis, we observed 39% reduced odds of moderately or severely impaired oxygenation among MICBG406A-homozygous individuals (95% CI, 0.43-0.86). BAL NK cells were less frequent and less mature in participants with MICBG406A. Expression of missense variant protein MICBD136N in cultured cells resulted in reduced surface MICB and reduced NKG2D ligation relative to wild-type MICB. Coculture of variant MICBD136N cells with NK cells resulted in less NKG2D activation and less susceptibility to NK cell killing relative to the wild-type cells. Conclusions: These data support a role for MICB signaling through the NKG2D receptor in mediating ALI, suggesting a novel therapeutic approach.

Lung transplantation for COVID-2019 respiratory failure in the United States: Outcomes 1-year posttransplant and the impact of preoperative extracorporeal membrane oxygenation support.

OBJECTIVE: Patients with end-stage respiratory failure after severe coronavirus disease 2019 (COVID-19) infection may benefit from lung transplant; however, data on transplant outcomes and the impact of prolonged circulatory support before transplant in these patients are limited. METHODS: We assessed survival, postoperative complications, and the impact of pretransplant extracorporeal membrane oxygenation (ECMO) in patients undergoing lung transplant in the United States from August 2020 through March 2022 using records validated by United Network for Organ Sharing experts and extracted from the United Network for Organ Sharing database. RESULTS: In 305 patients with COVID-19-related respiratory failure and validated data, survival for up to 1-year posttransplant did not differ between 188 patients with COVID-19-related acute respiratory distress syndrome and 117 patients with post-COVID-19 pulmonary fibrosis (P = .8). Pretransplant ECMO support (median 66 days) was required in 191 patients (63%), and venovenous ECMO was used in 91.2% of patients. One-, 6-, and 12-month survival was not significantly different between patients requiring ECMO and patients without ECMO (95.8% vs 99.1%, 93.1% vs 96.4%, 84.8% vs 90.9%, P = .2) In addition, 1-year survival was similar in recipients requiring ECMO for COVID-19 lung failure and recipients requiring ECMO for non-COVID-19 restrictive lung failure (84.8% vs 78.0%, P = .1). CONCLUSIONS: These findings suggest that lung transplant in patients with COVID-19 respiratory failure yields acceptable 1-year outcomes. Despite an often more complex postoperative course, prolonged ECMO pretransplant in well-selected patients was associated with adequate clinical and functional status.

Factors associated with aeroallergen testing among adults with asthma in a large health system.

Background: Aeroallergen testing informs precision care for adults with asthma, yet the epidemiology of testing in this population remains poorly understood. Objective: We sought to identify factors associated with receiving aeroallergen testing, the results of these tests, and subsequent reductions in exacerbation measures among adults with asthma. Methods: We used electronic health record data to conduct a retrospective, observational cohort study of 30,775 adults with asthma who had an office visit with a primary care provider or an asthma specialist from January 1, 2017, to August 26, 2022. We used regression models to identify (1) factors associated with receiving any aeroallergen test and tests to 9 allergen categories after the index visit, (2) factors associated with positive test results, and (3) reductions in asthma exacerbation measures in the year after testing compared with before testing. Results: Testing was received by 2201 patients (7.2%). According to multivariable models, receiving testing was associated with having any office visit with an allergy/immunology specialist during the study period (odds ratio [OR] = 91.3 vs primary care only [P < .001]) and having an asthma emergency department visit (OR = 1.62 [P = .004]) or hospitalization (OR = 1.62 [P = .03]) in the year before the index visit. Age 65 years or older conferred decreased odds of testing (OR = 0.74 vs age 18-34 years [P = .008]) and negative test results to 6 categories (P ≤ .04 for all comparisons). Black race conferred increased odds of testing (OR =1.22 vs White race [P = .01]) and positive test results to 8 categories (P < .04 for all comparisons). Exacerbation measures decreased after testing. Conclusion: Aeroallergen testing was performed infrequently among adults with asthma and was associated with reductions in asthma exacerbation measures.

Social memory deficit caused by dysregulation of the cerebellar vermis.

Social recognition memory (SRM) is a key determinant of social interactions. While the cerebellum emerges as an important region for social behavior, how cerebellar activity affects social functions remains unclear. We selectively increased the excitability of molecular layer interneurons (MLIs) to suppress Purkinje cell firing in the mouse cerebellar vermis. Chemogenetic perturbation of MLIs impaired SRM without affecting sociability, anxiety levels, motor coordination or object recognition. Optogenetic interference of MLIs during distinct phases of a social recognition test revealed the cerebellar engagement in the retrieval, but not encoding, of social information. c-Fos mapping after the social recognition test showed that cerebellar manipulation decreased brain-wide interregional correlations and altered network structure from medial prefrontal cortex and hippocampus-centered to amygdala-centered modules. Anatomical tracing demonstrated hierarchical projections from the central cerebellum to the social brain network integrating amygdalar connections. Our findings suggest that the cerebellum organizes the neural matrix necessary for SRM.

Readmission Rates After Acute Respiratory Distress Syndrome in Children.

Importance: An increasing number of children survive after acute respiratory distress syndrome (ARDS). The long-term morbidity affecting these survivors, including the burden of hospital readmission and key factors associated with readmission, is unknown. Objective: To determine 1-year readmission rates among survivors of pediatric ARDS and to investigate the associations of 3 key index hospitalization factors (presence or development of a complex chronic condition, receipt of a tracheostomy, and hospital length of stay [LOS]) with readmission. Design, Setting, and Participants: This retrospective cohort study used data from the commercial or Medicaid IBM MarketScan databases between 2013 and 2017, with follow-up data through 2018. Participants included hospitalized children (aged ≥28 days to <18 years) who received mechanical ventilation and had algorithm-identified ARDS. Data analysis was completed from March 2022 to March 2023. Exposures: Complex chronic conditions (none, nonrespiratory, and respiratory), receipt of tracheostomy, and index hospital LOS. Main Outcomes and Measures: The primary outcome was 1-year, all-cause hospital readmission. Univariable and multivariable Cox proportional hazard models were created to test the association of key hospitalization factors with readmission. Results: One-year readmission occurred in 3748 of 13 505 children (median [IQR] age, 4 [0-14] years; 7869 boys [58.3%]) with mechanically ventilated ARDS who survived to hospital discharge. In survival analysis, the probability of 1-year readmission was 30.0% (95% CI, 29.0%-30.8%). One-half of readmissions occurred within 61 days of discharge (95% CI, 56-67 days). Both respiratory (adjusted hazard ratio [aHR], 2.69; 95% CI, 2.42-2.98) and nonrespiratory (aHR, 1.86; 95% CI, 1.71-2.03) complex chronic conditions were associated with 1-year readmission. Placement of a new tracheostomy (aHR, 1.98; 95% CI, 1.69-2.33) and LOS 14 days or longer (aHR, 1.87; 95% CI, 1.62-2.16) were associated with readmission. After exclusion of children with chronic conditions, LOS 14 days or longer continued to be associated with readmission (aHR, 1.92; 95% CI, 1.49-2.47). Conclusions and Relevance: In this retrospective cohort study of children with ARDS who survived to discharge, important factors associated with readmission included the presence or development of chronic medical conditions during the index admission, tracheostomy placement during index admission, and index hospitalization of 14 days or longer. Future studies should evaluate whether postdischarge interventions (eg, telephonic contact, follow-up clinics, and home health care) may help reduce the readmission burden.

Association of delivery risk phenotype with early-onset sepsis in preterm infants.

OBJECTIVE: To determine delivery risk phenotype-specific incidence of early-onset sepsis (EOS) among preterm infants. STUDY DESIGN: Retrospective cohort study of infants born <35 weeks' gestation at four perinatal centers during 2017-2021. Infants were classified into one of six delivery risk phenotypes incorporating delivery mode, presence of labor, and duration of rupture of membranes (ROM). The primary outcome was EOS incidence within the overall cohort and each risk phenotype. RESULTS: Among 2937 preterm infants, 21 had EOS (0.7%, or 7.1 cases/1000 preterm infants). The majority of EOS cases (13/21, 62%) occurred in the setting of prolonged ROM ≥ 18 h, with a phenotype incidence of 23.8 cases/1000 preterm infants. There were no EOS cases among infants born by cesarean section without ROM (with or without labor), nor via cesarean section with ROM < 18 h without labor. CONCLUSION: Delivery risk phenotyping may inform EOS risk stratification in preterm infants.

Poor functional status at the time of waitlist for pediatric lung transplant is associated with worse pretransplant outcomes.

BACKGROUND: Whether functional status is associated with survival to pediatric lung transplant is unknown. We hypothesized that completely dependent functional status at waitlist registration, defined using Lansky Play Performance Scale (LPPS), would be associated with worse outcomes. METHODS: Retrospective cohort study of pediatric lung transplant registrants utilizing United Network for Organ Sharing's Standard Transplant Analysis and Research files (2005-2020). Primary exposure was completely dependent functional status, defined as LPPS score of 10-40. Primary outcome was waitlist removal for death/deterioration with cause-specific hazard ratio (CSHR) regression. Subdistribution hazard regression (SHR, Fine and Gray) was used for the secondary outcome of waitlist removal due to transplant/improvement with a competing risk of death/deterioration. Confounders included: sex, age, race, diagnosis, ventilator dependence, extracorporeal membrane oxygenation, year, and listing center volume. RESULTS: A total of 964 patients were included (63.5% ≥ 12 years, 50.2% cystic fibrosis [CF]). Median waitlist days were 95; 20.1% were removed for death/deterioration and 68.2% for transplant/improvement. Completely dependent functional status was associated with removal due to death/deterioration (adjusted CSHR 5.30 [95% CI 2.86-9.80]). This association was modified by age (interaction p = 0.0102), with a larger effect for age ≥12 years, and particularly strong for CF. In the Fine and Gray model, completely dependent functional status did not affect the risk of removal due to transplant/improvement with a competing risk of death/deterioration (adjusted SHR 1.08 [95% CI 0.77-1.49]). CONCLUSIONS: Pediatric lung transplant registrants with the worst functional status had worse pretransplant outcomes, especially for adolescents and CF patients. Functional status at waitlist registration may be a modifiable risk factor to improve survival to lung transplant.

Development and validation of a population pharmacokinetic model to guide perioperative tacrolimus dosing after lung transplantation.

Background: Tacrolimus therapy is standard of care for immunosuppression after lung transplantation. However, tacrolimus exposure variability during the early postoperative period may contribute to poor outcomes in this population. Few studies have examined tacrolimus pharmacokinetics (PK) during this high-risk time period. Methods: We conducted a retrospective pharmacokinetic study in lung transplant recipients at the University of Pennsylvania who were enrolled in the Lung Transplant Outcomes Group (LTOG) cohort. We derived a model in 270 patients using NONMEM (version 7.5.1) and examined validity in a separate cohort of 114 patients. Covariates were examined with univariate analysis and multivariable analysis was developed using forward and backward stepwise selection. Performance of the final model in the validation cohort was examined with calculation of mean prediction error (PE). Results: We developed a one-compartment base model with a fixed rate absorption constant. Significant covariates in multivariable analysis were postoperative day, hematocrit, transplant type, CYP3A5 genotype, total body weight, and time-varying postoperative day, hematocrit, and CYP inhibitor drugs. The strongest predictor of tacrolimus clearance was postoperative day, with median predicted clearance increasing more than threefold over the 14 day study period. In the validation cohort, the final model showed a mean PE of 36.4% (95%CI 30.8%-41.9%) and a median PE of 7.2% (IQR -29.3%-70.53%). Conclusion: Postoperative day was the strongest predictor of tacrolimus exposure in the early post-lung transplant period. Future multicenter studies employing intensive sampling to examine a broad set of variables related to critical illness physiology are needed to understand determinants of clearance, volume of distribution and absorption in this population.