Jason D. Christie

· MD MSCEVerified

University of Pennsylvania · Rehabilitation Medicine

Active 1988–2026

h-index101

Citations40.7k

Papers672152 last 5y

Funding$43.1M2 active

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About

Jason D. Christie, MD, MSCE, is the Paul F. Harron, Jr. Family Professor and a member of the Biomedical Graduate Group at the Perelman School of Medicine at the University of Pennsylvania. He serves as the Chief of the Pulmonary, Allergy, and Critical Care Division and is a senior scholar at the Center for Clinical Epidemiology and Biostatistics. His research focuses on translational studies of the risks, pathogenesis, treatment, and outcomes of acute lung injury in both transplant and non-transplant human populations. Dr. Christie's work integrates bench research with epidemiological approaches to develop new definitions of human syndromes, improve diagnostics and prognostics, and identify targeted therapies for advanced lung diseases and critical illnesses. He is the founder of the lung transplant outcomes group (LTOG), a multicentered cohort study investigating the etiology and pathogenesis of acute lung injury following lung transplantation, known as primary graft dysfunction. His research themes include mechanisms of clinical factors that elevate PGD risk, such as donor smoke exposure, recipient obesity, pulmonary hypertension, alterations in lung microbiome, and autoimmunity to lung collagens. His multidisciplinary work encompasses genetics, innate immunity, regulatory T-cells, innate lymphoid cell populations, ischemia-reperfusion injury, inflammation, and autoimmunity.

Research topics

Medicine
Internal medicine
Intensive care medicine
Immunology
Surgery

Selected publications

Latent Class Analysis Identifies Pulmonary Function Trajectory Phenotypes in Lung Transplant Recipients with Chronic Allograft Dysfunction
medRxiv · 2026-04-23
articleOpen access
Background: We aimed to identify data-driven FEV1 trajectory phenotypes post-chronic lung allograft dysfunction (CLAD), relate these phenotypes to patient factors and future graft loss, and develop a classification approach for prospective patients. Methods: We studied adult first lung recipients with probable CLAD from two prospective multicenter cohorts: CTOT-20 (n=206) and LTOG (n=1418). FEV1 trajectories over the first nine months post-CLAD were characterized using joint latent class mixed models, jointly modelling time-to-graft loss to account for informative censoring. Models were fit independently in both cohorts and also only among LTOG bilateral recipients. A classification and regression tree (CART) model was derived in LTOG bilateral recipients and applied to CTOT-20 bilateral recipients. Findings: Four distinct early FEV1 trajectory classes were identified in CTOT-20, with large differences in nine-month graft loss (72·3%, 31·1%, 2·2%, 0%). In LTOG, similar trajectory patterns were reproduced, with an additional class demonstrating early post-CLAD FEV1 improvement. Among bilateral recipients, trajectory classes showed a clear risk gradient, including a high-risk class with 100% graft loss and a low-risk class with no early graft loss. A CART model incorporating clinical and spirometric variables demonstrated good discrimination in LTOG bilateral recipients (multiclass AUC 0·85) and consistent class assignment and trajectory patterns when applied to CTOT-20. Interpretation: We identified reproducible, clinically meaningful early post-CLAD FEV1 trajectory phenotypes with differential graft loss risk. These phenotypes and a pragmatic classification tool may support risk stratification, trial enrichment, and improved prognostication for patients and clinicians. Funding: National Institutes of Health, Cystic Fibrosis Foundation.
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Impact of the COVID-19 pandemic on adult asthma-related health care utilization
Journal of Allergy and Clinical Immunology Global · 2026-02-24
articleOpen access
Background: The coronavirus 2019 disease (COVID-19) pandemic prompted major disruptions in chronic disease self-management and health care delivery, yet its impact on adults with asthma remains poorly characterized. Objective: Our aim was to assess changes in asthma-related health care utilization among adults during the COVID-19 pandemic (2020) compared with before the pandemic (2017-2019) and after the pandemic (2021-2024) within a large, multihospital health system. Methods: We conducted a retrospective electronic health record-based study of 42,242 adults with asthma who were receiving care at Penn Medicine from 2017 to 2024. Weekly counts of 5 encounter types (refill, telemedicine, telephone/audio, outpatient, and emergency encounters) and prescriptions for short-acting β-agonists, inhaled corticosteroids, and oral corticosteroids were compared across years. Generalized linear models evaluated changes in encounter rates during the pandemic and postpandemic periods relative to prepandemic levels, stratified by key transition intervals in 2020. Results: From 2017 to 2019, adults averaged 397 weekly asthma-related visits; in 2020, this number increased to 481. During the lockdown weeks, refill and telemedicine encounters rose by 123% and 36,445%, respectively, whereas outpatient visits declined by 65%. Prescriptions for short-acting β-agonists and inhaled corticosteroids increased by 73% and 43%, respectively, whereas oral corticosteroid prescriptions decreased by 5%. Primary care visits spiked during the lockdown, whereas allergy/immunology and pulmonary encounters remained stable throughout the year. Conclusion: The COVID-19 pandemic was associated with major shifts in adult asthma care, characterized by short-term surges in primary care visits and medication refills and reductions in in-person encounters. These patterns illustrate the capacity of asthma care systems to rapidly adapt, and they highlight the need to tailor future crisis response strategies to adult patients.
Publisher DOI
Clinical features associated with chronic lung allograft dysfunction progression in a multicenter cohort
American Journal of Respiratory and Critical Care Medicine · 2026-01-23 · 2 citations
articleOpen access
RATIONALE: Clinical features that impact outcomes in lung recipients with chronic lung allograft dysfunction (CLAD) are uncertain and limited by existing approaches to phenotyping that rely on measures inconsistently performed or not standardized across centers. OBJECTIVE: We used data from the prospective multicenter Lung Transplant Outcomes Group (LTOG) cohort study to determine if routine, objective clinical measures at CLAD diagnosis impact progression to graft loss (death/retransplantation). METHODS: The analysis included 2386 adult lung recipients from 9 US centers. Probable CLAD was defined according to International Society for Heart and Lung Transplantation criteria. Cox models were fit for time from probable CLAD to graft loss as a function of each clinical feature of interest including CLAD stage (1-4), CLAD timing (early-onset, <2 years posttransplant), FVC loss (FVCCLAD/FVCBest <0.8), and FEV1/FVC ratio <0.7. Models included a random effect for center and were adjusted for recipient age, sex, transplant type, and native lung disease. MEASUREMENTS AND MAIN RESULTS: Probable CLAD developed in 1418 patients (59.4%). At onset, 80.7% had stage 1 CLAD, 41.3% had early-onset CLAD, 35.8% had FVC loss, and 46.5% had an FEV1/FVC ratio <0.7. In adjusted analyses, patients with CLAD stage ≥2, early-onset CLAD, and FVC loss had significantly higher hazards for graft loss, while FEV1/FVC <0.7 was associated with reduced graft loss risk. CONCLUSIONS: We provide compelling evidence that routine, objective measures at CLAD onset inform CLAD progression risk. Such stratification of disease behavior is important to patient prognostication and may inform the design of future CLAD trials.
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Utility of donor-derived cell-free DNA testing after lung transplantation in the precision medicine era
The Journal of Heart and Lung Transplantation · 2026-04-01
article
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CT-adipose measures identify severe SARS-CoV-2 risk beyond traditional obesity metrics: a C4R cohort study
BMC Pulmonary Medicine · 2026-05-25
articleOpen access
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Acute lung allograft dysfunction predicts lung allograft failure: Construct validity of the 2026 International Society for Heart and Lung Transplantation spirometric definition
The Journal of Heart and Lung Transplantation · 2026-04-11
articleOpen accessSenior author
INTRODUCTION: Acute lung allograft dysfunction (ALAD) has been proposed as a screening criterion to identify lung transplant recipients at increased risk for graft loss. ALAD was defined formally in a 2026 International Society for Heart and Lung Transplantation (ISHLT) Delphi consensus statement but has not been empirically evaluated. We sought to test the construct validity of the ISHLT ALAD definition by testing the hypothesis that ALAD is associated with increased risk of graft failure. METHODS: We included 86,885 spirometry measurements from 2,877 participants in the 8-center Lung Transplant Outcomes Group cohort. ALAD was defined as a ≥10% decline in FEV1 from the maximum value over the preceding 180 days and coded along with 90-day follow-up categories of resolved, persistent, progressive, and rapidly progressive. We assessed whether ALAD classifications diverged in predictions of time to death or re-transplantation in multivariable-adjusted time-dependent and landmark Cox proportional hazards models. RESULTS: ALAD had a prevalence of 15%. While resolution was seen in 40%, ALAD conferred a 4.93-fold graft failure hazard (95% CI 4.47-5.45, 7.4 years median follow-up), independent of concurrent chronic or baseline lung allograft dysfunction (CLAD or BLAD) status. Resolved ALAD was not associated with increased graft failure risk, but persistent, progressive, rapidly progressive, and no follow-up FEV1 ALAD categories were associated with increasing hazards for graft failure. A 10-percent threshold for FEV1 decline and a 180-day window to set the FEV1 baseline demonstrated optimal discrimination. CONCLUSION: The 2026 ISHLT spirometric ALAD definitions identify graft failure risk, supporting their relevance in clinical interventions and further research.
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Associations with Asthma Trigger Avoidance Behaviors and Related Advice-Giving Among Adults with Asthma
Journal of Allergy and Clinical Immunology · 2026-02-01
article
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Prolonged Invasive Mechanical Ventilation is Associated With Decreased Survival After Lung Transplantation Among Recipients With Primary Graft Dysfunction: A Lung Transplant Outcomes Group Study
Clinical Transplantation · 2026-01-01 · 1 citations
articleOpen access
INTRODUCTION: Prolonged invasive mechanical ventilation (IMV) after lung transplantation is an appealing early prognostic outcome as it can be reproducibly assessed both prospectively and retrospectively. Whether use of IMV at 72 h after lung transplantation is associated with post-transplant graft survival is unknown. METHODS: We performed a retrospective cohort study of 1511 participants in the multi-center Lung Transplant Outcomes Group cohort (2011-2018). Using Cox proportional hazards models and restricted mean survival time, we investigated whether IMV at 72 h was associated with post-transplant graft survival. We secondarily evaluated whether IMV at 72 h was concordant with severe primary graft dysfunction (PGD). RESULTS: Participants requiring IMV at 72 h after transplant were sicker at transplantation (higher lung allocation score [LAS], increased extracorporeal membrane oxygenation, or IMV bridge) and more likely to have severe PGD. Use of IMV at 72 h was associated with 55% (95% CI 26%-92%) increased hazards of death or re-transplantation after adjustment for age, ECMO, diagnosis, LAS, and intra-operative transfusion. The association between IMV and graft survival was modified by severe PGD (p-for interaction 0.002) but not by pre-transplant ECMO (p-for interaction 0.88) or pre-transplant IMV (p-for interaction 0.92). IMV was associated with increased risk of death or re-transplantation among those with PGD (HR 2.35, 95% CI 1.43-3.85) but not among those without PGD (HR 1.04, 95% CI 0.77-1.41). CONCLUSION: Requirement of IMV at 72 h is an important early post-transplant outcome associated with post-transplant survival. This appears driven by those with severe PGD.
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Lung transplant for CF: Low lung bacterial burden and immune mediators in year one associate with CLAD development
Journal of Cystic Fibrosis · 2025-10-10
article
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Impact of the COVID-19 Pandemic on Adult Asthma-Related Healthcare Utilization
medRxiv · 2025-09-21
preprintOpen access
BACKGROUND: The COVID-19 pandemic prompted unprecedented changes to chronic disease self-management and healthcare systems worldwide, including shifts in access to services and medications. While children with asthma had decreased exacerbations and healthcare encounters during 2020, the impact of lockdowns on adults with asthma, who faced different challenges during the pandemic than children, are less understood. OBJECTIVE: We sought to characterize changes in adult asthma-related healthcare utilization during the COVID-19 pandemic in 2020 versus prior (2017-2019) and subsequent (2021-2024) years by leveraging electronic health record (EHR) data from a large, multi-hospital health system in a major US city. METHODS: We conducted a retrospective EHR database study of 42,242 adults with asthma who received care at Penn Medicine from 2017 to 2024. We analyzed weekly encounter counts across five encounter types (refill, telemedicine, telephone/audio, outpatient, emergency encounters) and prescriptions for short-acting beta agonists (SABA), inhaled corticosteroids (ICS), and oral corticosteroids (OCS). Generalized linear models assessed changes in asthma-related encounter rate in pandemic (2020) and post-pandemic (2021-2024) periods relative to pre-pandemic (2017-2019). We stratified on weekly intervals that captured transitional timepoints in healthcare utilization in 2020 (Weeks 1-8, 9-18, and 19-52). RESULTS: In 2017-2019, there were on average 397 weekly visits for asthma at Penn Medicine; in 2020, the weekly average increased to 481. This change was driven primarily by a surge during the lockdown weeks in refill and telemedicine encounters by 123% and 36,445%, respectively and by a decrease in outpatient visits by 65%. During the lockdown weeks in 2020, asthma related prescriptions of SABA and ICS prescriptions increased 73% and 43%, respectively, compared to pre-pandemic years, while OCS prescriptions decreased by 5%. White patients showed earlier healthcare-seeking responses than other racial groups. Changes persisted in post-pandemic years as the average of weekly asthma-related visits was 445 in 2021-2024. Telemedicine remained 38-76 times higher than pre-pandemic baseline, refills doubled compared to 2017-2019 levels, and outpatient visits remained 35-43% below pre-pandemic levels. CONCLUSION: COVID-19 transformed adult asthma care delivery and led to sustained increases in virtual care and medication refills potentially due to virtual care compensating for reductions in traditional outpatient encounters.
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