31 results on '"Ashley Y. Choi"'
Search Results
2. C3 complement inhibition prevents antibody-mediated rejection and prolongs renal allograft survival in sensitized non-human primates
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Robin Schmitz, Zachary W. Fitch, Paul M. Schroder, Ashley Y. Choi, Miriam Manook, Janghoon Yoon, Mingqing Song, John S. Yi, Sanjay Khandelwal, Gowthami M. Arepally, Alton B. Farris, Edimara S. Reis, John D. Lambris, Jean Kwun, and Stuart J. Knechtle
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Science - Abstract
Donor-specific antibodies in sensitized recipients may cause kidney transplant rejection. Here the authors show that complement component C3 inhibition prolongs graft survival by inhibiting T and B cell proliferation/activation and hence tissue injury, despite antibody levels remaining unaffected.
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- 2021
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3. Emerging New Approaches in Desensitization: Targeted Therapies for HLA Sensitization
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Ashley Y. Choi, Miriam Manook, Danae Olaso, Brian Ezekian, Jaeberm Park, Kyle Freischlag, Annette Jackson, Stuart Knechtle, and Jean Kwun
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sensitization ,desensitization ,alloantibody ,plasma cells ,germinal center ,Immunologic diseases. Allergy ,RC581-607 - Abstract
There is an urgent need for therapeutic interventions for desensitization and antibody-mediated rejection (AMR) in sensitized patients with preformed or de novo donor-specific HLA antibodies (DSA). The risk of AMR and allograft loss in sensitized patients is increased due to preformed DSA detected at time of transplant or the reactivation of HLA memory after transplantation, causing acute and chronic AMR. Alternatively, de novo DSA that develops post-transplant due to inadequate immunosuppression and again may lead to acute and chronic AMR or even allograft loss. Circulating antibody, the final product of the humoral immune response, has been the primary target of desensitization and AMR treatment. However, in many cases these protocols fail to achieve efficient removal of all DSA and long-term outcomes of patients with persistent DSA are far worse when compared to non-sensitized patients. We believe that targeting multiple components of humoral immunity will lead to improved outcomes for such patients. In this review, we will briefly discuss conventional desensitization methods targeting antibody or B cell removal and then present a mechanistically designed desensitization regimen targeting plasma cells and the humoral response.
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- 2021
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4. Incidence and Diagnostic Challenges of Bowel Ischemia after Continuous-flow Left Ventricular Assist Device Therapy
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Michelle A Mendiola, Suresh M. Agarwal, Carmelo A. Milano, Jacob N. Schroder, Fabian Jimenez Contreras, Muath Bishawi, Jatin Anand, Cory Vatsaas, Ashley Y. Choi, Samantha E. Halpern, and Mani A. Daneshmand
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Adult ,Male ,medicine.medical_specialty ,medicine.medical_treatment ,Biomedical Engineering ,Biophysics ,Bioengineering ,Article ,Biomaterials ,Ischemia ,medicine ,Humans ,Renal replacement therapy ,Stroke ,Retrospective Studies ,Heart Failure ,business.industry ,Incidence ,Atrial fibrillation ,General Medicine ,medicine.disease ,Surgery ,Treatment Outcome ,Ventricular assist device ,Current Procedural Terminology ,Female ,Kidney Diseases ,Heart-Assist Devices ,business ,Complication ,Kidney disease ,Destination therapy - Abstract
Long-term continuous-flow left ventricular assist device (CFLVAD) therapy is limited by complications. Compared with stroke and renal dysfunction, post-CFLVAD bowel ischemia is poorly characterized. Adult patients who underwent first-time durable CFLVAD implantation at our institution between 2008 and 2018 were identified and screened for bowel ischemia using Current Procedural Terminology codes for abdominal surgical exploration and International Classification of Disease codes for intestinal vascular insufficiency. Patients who developed biopsy-proven bowel ischemia (cases) were matched to controls (1:1, nearest neighbor, caliper = 0.29) based on preoperative characteristics. Incidences of postoperative right heart failure and renal replacement therapy were compared using McNemar's test. One year survival was estimated using the Kaplan-Meier method. Overall, 711 patients underwent CFLVAD implantation. Nineteen (2.7%) developed bowel ischemia (cases) median 17 days postimplantation (IQR 8-71). The majority of cases were male (78.9%), Black (63.2%), received HeartMate II (57.9%), treated as destination therapy (78.9%), and had a history of hypertension (89.5%), chronic kidney disease (84.2%), hyperlipidemia (84.2%), smoking (78.9%), and atrial fibrillation (57.9%). Post-LVAD, case patients were more likely to develop moderate-severe right heart failure (89.5% vs. 68.4%, p = 0.005), require renal replacement therapy (21.1% vs. 0%, p < 0.001), and less likely to survive to discharge (52.6% vs. 89.5%, p = 0.02) compared with controls. Case subjects demonstrated worse 1 year survival. While less common than stroke and renal dysfunction, post-CFLVAD bowel ischemia is associated with high 1 year mortality. Multi-institutional registries should consider reporting abdominal complications such as bowel ischemia as an adverse event to further investigate these trends and identify predictors of this complication to reduce patient mortality.
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- 2023
5. C3 complement inhibition prevents antibody-mediated rejection and prolongs renal allograft survival in sensitized non-human primates
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Zachary W. Fitch, John D. Lambris, Miriam Manook, Edimara S. Reis, Paul M. Schroder, Robin Schmitz, Mingqing Song, Sanjay Khandelwal, Stuart J. Knechtle, Janghoon Yoon, John S. Yi, Ashley Y. Choi, Alton B. Farris, Gowthami M. Arepally, and Jean Kwun
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Graft Rejection ,Male ,Globulin ,Pyridones ,T-Lymphocytes ,Science ,General Physics and Astronomy ,Renal function ,Lymphocyte Activation ,General Biochemistry, Genetics and Molecular Biology ,B-cell proliferation ,Antibodies ,Medicine ,Animals ,Transplantation, Homologous ,Cell Proliferation ,B-Lymphocytes ,Multidisciplinary ,biology ,business.industry ,Graft Survival ,General Chemistry ,Complement C3 ,Kidney Transplantation ,Macaca mulatta ,Antibody mediated rejection ,Immunology ,biology.protein ,Renal allograft ,Lymphocyte activation ,Cytokines ,C3 complement ,Antibody ,business - Abstract
Sensitized kidney transplant recipients experience high rates of antibody-mediated rejection due to the presence of donor-specific antibodies and immunologic memory. Here we show that transient peri-transplant treatment with the central complement component C3 inhibitor Cp40 significantly prolongs median allograft survival in a sensitized nonhuman primate model. Despite donor-specific antibody levels remaining high, fifty percent of Cp40-treated primates maintain normal kidney function beyond the last day of treatment. Interestingly, presence of antibodies of the IgM class associates with reduced median graft survival (8 vs. 40 days; p = 0.02). Cp40 does not alter lymphocyte depletion by rhesus-specific anti-thymocyte globulin, but inhibits lymphocyte activation and proliferation, resulting in reduced antibody-mediated injury and complement deposition. In summary, Cp40 prevents acute antibody-mediated rejection and prolongs graft survival in primates, and inhibits T and B cell activation and proliferation, suggesting an immunomodulatory effect beyond its direct impact on antibody-mediated injury. Donor-specific antibodies in sensitized recipients may cause kidney transplant rejection. Here the authors show that complement component C3 inhibition prolongs graft survival by inhibiting T and B cell proliferation/activation and hence tissue injury, despite antibody levels remaining unaffected.
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- 2021
6. Safety and efficacy of an implantable device for management of gastroesophageal reflux in lung transplant recipients
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Samantha E. Halpern, Hai Salfity, Aryaman Gupta, Jacob A. Klapper, Matthew G. Hartwig, Ashley Y. Choi, and Oliver K. Jawitz
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Pulmonary and Respiratory Medicine ,medicine.medical_specialty ,Lung ,business.industry ,medicine.medical_treatment ,Reflux ,030230 surgery ,medicine.disease ,Pulmonary function testing ,Surgery ,Transplantation ,03 medical and health sciences ,0302 clinical medicine ,medicine.anatomical_structure ,030220 oncology & carcinogenesis ,Ambulatory ,Cohort ,GERD ,Medicine ,Lung transplantation ,Original Article ,business - Abstract
BACKGROUND: Magnetic sphincter augmentation (MSA) is a promising minimally invasive surgical technique for management of gastroesophageal reflux disease (GERD); however, device implantation after transplantation has not been studied and may be concerning in these immunosuppressed patients. We explored the safety of the LINX Reflux Management System (MSA device) for management of GERD following lung transplantation (LTx). METHODS: Lung transplant recipients who underwent LINX implantation at our institution between 2017 and 2019 were followed prospectively in the Reflux Following Lung Transplantation and Associated Treatment Registry. Ambulatory pH testing and acid-suppressing medication use were compared before and after LINX implantation. One-year outcomes and change in pulmonary function were compared between matched LINX and fundoplication groups. RESULTS: Of 17 patients who underwent post-lung transplant LINX implantation, 8 (47.1%) agreed to undergo post-LINX pH testing. Three/eight (37.5%) patients achieved normal esophageal acid exposure time; 14 (82.4%) remained on acid-suppressing medication at one-year under the direction of their transplant teams. One-year patient survival and change in pulmonary function were similar between groups. LINX patients experienced more early side effects. CONCLUSIONS: Use of the LINX MSA device in a cohort of lung transplant recipients at our institution was associated with similar short-term safety compared to traditional fundoplication, however assessment of efficacy was limited. Further investigation is needed to characterize the long-term efficacy of LINX implantation after LTx.
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- 2021
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7. Lung Transplantation After Ex Vivo Lung Perfusion Early Outcomes From a US National Registry
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Ashley Y. Choi, Vignesh Raman, Samantha E. Halpern, David Becerra, Jacob A. Klapper, Julie Doberne, Matthew G. Hartwig, and Oliver K. Jawitz
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Adult ,Extracorporeal Circulation ,medicine.medical_specialty ,medicine.medical_treatment ,Article ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,medicine ,Extracorporeal membrane oxygenation ,Humans ,Lung transplantation ,Registries ,Lung ,business.industry ,Ex vivo lung perfusion ,Hazard ratio ,Odds ratio ,Tissue Donors ,Confidence interval ,Perfusion ,medicine.anatomical_structure ,030220 oncology & carcinogenesis ,030211 gastroenterology & hepatology ,Surgery ,National registry ,business ,Lung Transplantation - Abstract
Objective The objective of this study was to examine early lung transplant outcomes following EVLP using a large national transplant registry. Summary of background data Lung transplantation in the United States continues to be constrained by a limited supply of donor organs. EVLP has the potential to significantly increase the available pool of donor lung allografts through the reconditioning of "marginal" organs. Methods The united network for organ sharing registry was queried for all adults (age ≥18) who underwent first-time lung transplantation between March 2018 (when united network for organ sharing began collecting confirmed donor EVLP status) and June 2019. Transplants were stratified by EVLP use. The primary outcome was short-term survival and secondary outcomes included acute rejection before discharge and need for extracorporeal membrane oxygenation support post-transplant. Results A total of 3334 recipients met inclusion criteria including 155 (5%) and 3179 (95%) who did and did not receive allografts that had undergone EVLP, respectively. On unadjusted descriptive analysis, EVLP and non-EVLP cohorts had similar 180-day survival (92% vs 92%, P = 0.9). EVLP use was associated with a similar rate of acute rejection (13% vs 9%, P = 0.08) but increased rate of early extracorporeal membrane oxygenation use (12% vs 7%, P = 0.04). After adjustment, EVLP use was not associated with significantly increased mortality (adjusted hazard ratio 0.99, 95% confidence interval 0.62-1.58) or acute rejection (adjusted odds ratio 0.89, 95% confidence interval 0.40-1.97) compared to non-EVLP use. Conclusions In the largest national series of EVLP lung transplant recipients, EVLP is associated with early recipient outcomes comparable to that of non-EVLP recipients with similar baseline characteristics. Longer term follow-up data is needed to further assess the impact of EVLP on post-lung transplant outcomes.
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- 2020
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8. Belatacept-Based Maintenance Immunosuppression Controls the Post-Transplant Humoral Immune Response in Highly Sensitized Nonhuman Primates
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Robin Schmitz, Zachary W. Fitch, Miriam Manook, Paul M. Schroder, Ashley Y. Choi, Danae Olaso, Janghoon Yoon, Yeeun Bae, Brian I. Shaw, Mingqing Song, Maragatha Kuchibhatla, Alton B. Farris, Allan Kirk, Jean Kwun, and Stuart J. Knechtle
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Abatacept ,Immunosuppression Therapy ,Sirolimus ,Innovative Technology and Methodology ,Animals ,Humans ,General Medicine ,Tacrolimus ,Antibodies ,Immunity, Humoral - Abstract
Preexisting donor-specific antibodies (DSA) to MHC antigens increase the risk of antibody-mediated rejection (AMR) in sensitized transplant recipients and reduces graft survival. Pretransplant desensitization with costimulation blockade and proteasome inhibition has facilitated transplantation in our preclinical nonhuman primate (NHP) model. However, long-term graft survival is limited by rebound of DSA after transplantation. In this study, we performed kidney transplants between highly sensitized, maximally MHC-mismatched NHPs (n=14). At kidney transplantation, primates received T cell depletion with rhesus-specific anti-thymocyte globulin (rhATG; n=10) or monoclonal anti-CD4 and anti-CD8 antibodies (n=4). Maintenance immunosuppression consisted of belatacept and tacrolimus (n=5) or belatacept and rapamycin (n=9) with steroids. Rebound of DSA post–kidney transplantation was significantly reduced compared with maintenance immunosuppression with tacrolimus, mycophenolate, and steroids. Protocol lymph node biopsy specimens showed a decrease in germinal center activity, with low frequencies of T follicular helper cells and class-switched B cells after kidney transplantation. Combined belatacept and rapamycin was superior in controlling viral reactivation, enabling weaning of ganciclovir prophylaxis. Tacrolimus was associated with increased morbidity that included cytomegalovirus and parvovirus viremia and post-transplant lymphoproliferative disorder. All primates in the tacrolimus/belatacept group failed discontinuation of antiviral therapy. Overall, belatacept-based immunosuppression increased AMR-free graft survival by controlling post-transplant humoral responses in highly sensitized NHP recipients and should be further investigated in a human clinical trial.
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- 2022
9. Aggressive pursuit and utilization of non‐ideal donor lungs does not compromise post‐lung transplant survival
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Ashley Y. Choi, Jacob A. Klapper, Oliver K. Jawitz, Matthew G. Hartwig, John C. Haney, Samantha E. Halpern, and Vignesh Raman
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Adult ,Organ procurement organization ,OPOS ,Transplantation ,medicine.medical_specialty ,Tissue and Organ Procurement ,Lung ,business.industry ,medicine.medical_treatment ,Graft Survival ,Primary Graft Dysfunction ,Article ,Tissue Donors ,Young Adult ,medicine.anatomical_structure ,Donation ,Internal medicine ,Extracorporeal membrane oxygenation ,Humans ,Medicine ,Lung transplantation ,business ,Lung Transplantation - Abstract
Background Organ procurement organizations (OPOs) vary in willingness to pursue and utilize non-ideal donor lungs; implications of these practices for lung transplant (LTx) recipients remain unclear. We examined associations between OPO-level behavior toward non-ideal donors and post-LTx outcomes. Methods Adult lung donors and corresponding adult first-time LTx recipients in the 2008-2019 UNOS registry were included. Non-ideal donors had any of age > 50, smoking history ≥20 pack-years, PaO2 /FiO2 ratio ≤350, donation after circulatory death, or increased risk status. OPOs were classified as least, moderately, or most aggressive based on non-ideal donor pursuit, consent attainment, lung recovery, and transplantation. Post-transplant outcomes were compared among aggressiveness strata. Results Of 22,795 recipients, 6229 (27.3%), 8256 (36.2%), and 8310 (36.5%) received lungs from least, moderately, and most aggressive OPOs, respectively. Moderately aggressive OPOs had the highest recipient rates of pre-discharge acute rejection, grade 3 primary graft dysfunction, postoperative extracorporeal membrane oxygenation, and longest lengths of stay. After adjustment, moderately and most aggressive OPOs had similar risks of recipient mortality as least aggressive OPOs. Conclusions The most and least aggressive OPOs achieve similar patient survival and short-term post-LTx outcomes. Aggressive pursuit and utilization of non-ideal donor lungs by less aggressive OPOs would likely expand the donor pool, without compromising recipient outcomes.
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- 2021
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10. Implications of declining donor offers with increased risk of disease transmission on waiting list survival in lung transplantation
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Mani A. Daneshmand, Michael S. Mulvihill, Matthew G. Hartwig, Muath Bishawi, John C. Haney, Cameron R. Wolfe, Ashley Y. Choi, Morgan L. Cox, Asishana A. Osho, and Jacob A. Klapper
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Adult ,Male ,Pulmonary and Respiratory Medicine ,medicine.medical_specialty ,Tissue and Organ Procurement ,Waiting Lists ,medicine.medical_treatment ,030204 cardiovascular system & hematology ,030230 surgery ,Infections ,Risk Assessment ,Article ,Donor Selection ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,parasitic diseases ,medicine ,Humans ,Lung transplantation ,Aged ,Retrospective Studies ,Transplantation ,Lung ,Proportional hazards model ,business.industry ,Middle Aged ,United States ,Survival Rate ,medicine.anatomical_structure ,Increased risk ,Waiting list ,Female ,Surgery ,Cardiology and Cardiovascular Medicine ,business ,Disease transmission ,Lung Transplantation ,Lung allocation score - Abstract
BACKGROUND: Donors with characteristics that may increase the likelihood of disease transmission with transplantation are noted as increased risk via Public Health Service criteria. This study aimed to establish the implications of declining an increased-risk donor (IRD) organ offer in lung transplantation. METHODS: Adult candidates waitlisted for isolated lung transplantation in the United States using the Organ Procurement and Transplantation Network/United Network of Organ Sharing registry from 2007 to 2017 were identified. Individual match run files identified candidate recipients who matched to an IRD offer. Competing-risks analysis ascertained the likelihood of survival to transplantation. A stratified Cox model and restricted mean survival times estimated the survival benefit associated with the acceptance of an IRD organ. RESULTS: A total of 6,963 candidates met inclusion criteria, and 1,473 (21.2%) accepted an IRD offer. Candidates who accepted an IRD offer were older, more likely to be male, and had a higher lung allocation score at the time of listing (all p < 0.05). At 1 year after an IRD offer decline, 70.5% of candidates underwent a lung transplant, 13.8% died or decompensated, and 14.9% were still awaiting transplant. Compared with those who declined, candidates who accepted the IRD offer had significantly improved cumulative mortality at 1 year (14.1% vs 23.9%, p < 0.001) and 5 years (48.4% vs 53.8%, p < 0.001). CONCLUSIONS: IRD organ declination is associated with a decreased rate of lung transplantation and worse survival. Overall post-transplant survival rates for those who survive to transplantation are equivalent.
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- 2019
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11. Dual procurement of lung and heart allografts does not negatively affect lung transplant outcomes
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Vignesh Raman, Jacob A. Klapper, Ashley Y. Choi, Fabian Jimenez Contreras, Oliver K. Jawitz, and Matthew G. Hartwig
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United Network for Organ Sharing ,Adult ,Male ,medicine.medical_specialty ,Tissue and Organ Procurement ,Kaplan-Meier Estimate ,Affect (psychology) ,Severity of Illness Index ,Article ,03 medical and health sciences ,Young Adult ,0302 clinical medicine ,Internal medicine ,Medicine ,Humans ,Prospective Studies ,Registries ,Aged ,Retrospective Studies ,Lung ,business.industry ,Graft Survival ,Middle Aged ,Allografts ,Circulatory death ,Tissue Donors ,Transplant Recipients ,Transplantation ,Donor group ,medicine.anatomical_structure ,Treatment Outcome ,030220 oncology & carcinogenesis ,Donation ,Concomitant ,Heart Transplantation ,030211 gastroenterology & hepatology ,Surgery ,Female ,business ,Respiratory Insufficiency ,Lung Transplantation - Abstract
Background The data that exists regarding multiorgan procurement outcomes is conflicted. Given the increasing demand for pulmonary allografts, it is critical to assess the impact of dual procurement on lung transplant recipient outcomes. Methods The United Network for Organ Sharing transplant registry was queried for all first-time adult (age ≥18) lung transplant recipients between 2006 and 2018 and stratified by concurrent heart donor status. Multiorgan transplant recipients and recipients with missing survival time were excluded. Donors were excluded if they were donating after circulatory death, did not consent or were not approached for heart donation, the heart was recovered for nontransplant purposes, or the heart was recovered for transplant but not transplanted. Post-transplant survival was analyzed using the Kaplan–Meier method and multivariable Cox proportional hazards regression. Results A total of 18,641 recipients met inclusion criteria, including 6230 (33.4%) in the nonheart donor group (NHD) and 12,409 (66.6%) in the heart donor group (HD). HD recipients demonstrated longer survival at 10 years posttransplant, with a median survival of 6.5 years as compared with 5.9 years in NHD recipients. On adjusted analysis, HD and NHD recipients demonstrated comparable survival (AHR 0.95, 95% CI 0.90-1.01). Conclusions Concomitant heart and lung procurement was not associated with worse survival. This finding encourages maximizing the number of organs procured from each donor, particularly in the setting of urgency-driven thoracic transplantation.
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- 2020
12. A three-tier system for evaluation of organ procurement organizations' willingness to pursue and utilize nonideal donor lungs
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Matthew G. Hartwig, Scott M. Palmer, Megan L. Neely, Oliver K. Jawitz, Alec McConnell, Sarah B. Peskoe, Vignesh Raman, Ashley Y. Choi, and Samantha E. Halpern
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OPOS ,Organ procurement organization ,Adult ,Tissue and Organ Procurement ,030230 surgery ,Article ,03 medical and health sciences ,0302 clinical medicine ,Tier 2 network ,Immunology and Allergy ,Medicine ,Humans ,Pharmacology (medical) ,Registries ,Lung ,Transplantation ,Risk aversion ,business.industry ,Organ Transplantation ,Middle Aged ,Tissue Donors ,Donor lungs ,Organ procurement ,Donation ,business ,Demography - Abstract
Lungs from “non-ideal,” but acceptable donors are underutilized, however organ procurement organization (OPO) metrics do not reflect the extent to which OPO-specific practices contribute to these trends. We developed a comprehensive system to evaluate non-ideal lung donor avoidance, or risk aversion among OPOs. Adult donors in the UNOS registry who donated ≥1 organ for transplantation between 2007–2018 were included. Non-ideal donors had any of age>50, smoking history ≥20 pack-years, PaO(2)/FiO(2) ratio ≤350, donation after circulatory death, or increased risk status. OPO-level risk aversion in donor pursuit, consent attainment, lung recovery, and transplantation was assessed. Among 83,916 donors, 70,372 (83.9%) were non-ideal. Unadjusted OPO-level rates of non-ideal donor pursuit ranged from 81–100%. In a three-tier system of overall risk aversion, tier 3 OPOs (least risk-averse) had the highest rates of non-ideal donor pursuit, consent attainment, lung recovery, and transplantation. Tier 1 OPOs (most risk-averse) had the lowest rates of donor pursuit, consent attainment, and lung recovery, but higher rates of transplantation compared to tier 2 OPOs (moderately risk-averse). Risk aversion varies among OPOs and across the donation process. OPO evaluations should reflect early donation process stages to best differentiate over- and underperforming OPOs and encourage optimal OPO-specific performance.
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- 2020
13. Preoperative carfilzomib and lulizumab based desensitization prolongs graft survival in a sensitized non-human primate model
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Zachary W. Fitch, Paul M. Schroder, Jean Kwun, Miriam Manook, Mingqing Song, Andrew S. Barbas, Stuart J. Knechtle, Janghoon Yoon, Robin Schmitz, Frank V. Leopardi, Alton B. Farris, Brian Ezekian, Bradley H. Collins, and Ashley Y. Choi
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0301 basic medicine ,Graft Rejection ,Primates ,Regulatory T cell ,medicine.medical_treatment ,Naive B cell ,030232 urology & nephrology ,chemical and pharmacologic phenomena ,Pharmacology ,Belatacept ,Article ,Abatacept ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Medicine ,Animals ,Humans ,IL-2 receptor ,Desensitization (medicine) ,business.industry ,Graft Survival ,CD28 ,Immunosuppression ,Carfilzomib ,030104 developmental biology ,medicine.anatomical_structure ,chemistry ,Nephrology ,Desensitization, Immunologic ,business ,Oligopeptides ,Immunosuppressive Agents ,medicine.drug - Abstract
Sensitized patients are difficult to transplant due to pre-formed anti-donor immunity. We have previously reported successful desensitization using carfilzomib and belatacept in a non-human primate (NHP) model. Here we evaluated selective blockade of the co-stimulatory signal (CD28-B7) with Lulizumab, which preserves the co-inhibitory signal (CTLA4-B7). Five maximally MHC-mismatched pairs of NHPs were sensitized to each other with two sequential skin transplants. Individuals from each pair were randomized to either desensitization with once-weekly Carfilzomib (27mg/m(2) IV) and Lulizumab (12.5mg/kg SC) over four weeks, or no desensitization (Control). NHPs then underwent life-sustaining kidney transplantation from their previous skin donor. Rhesus-specific anti-thymocyte globulin was used as induction therapy and immunosuppression maintained with tacrolimus, mycophenolate, and methylprednisolone. Desensitized subjects demonstrated a significant reduction in donor-specific antibody, follicular helper T cells (CD4(+)PD-1(+)ICOS(+)), and proliferating B cells (CD20(+)Ki67(+)) in the lymph nodes. Interestingly, regulatory T cell (CD4(+)CD25(+)CD127(lo)) frequency was maintained after desensitization in addition to increased frequency of naïve CD4 T cells (CCR7(+)CD45RA(+)) and naïve B cells (IgD(+)CD27(−)CD20(+)) in circulation. This was associated with significant prolongation in graft survival (MST = 5.8 ± 4.0 vs. 64.8 ± 36.3; p
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- 2020
14. Resection of the irradiated esophagus: the impact of lymph node yield on survival
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Carrie B. Moore, Ashley Y. Choi, Betty C. Tong, Matthew G. Hartwig, Thomas A. D'Amico, Babatunde A. Yerokun, Benjamin Y. Andrew, Morgan L. Cox, Michael S. Mulvihill, Valentine R Esposito, and Chi-Fu Jeffrey Yang
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medicine.medical_specialty ,Esophageal Neoplasms ,medicine.medical_treatment ,030230 surgery ,03 medical and health sciences ,Esophagus ,0302 clinical medicine ,medicine ,Humans ,Lymph node ,Neoplasm Staging ,Proportional Hazards Models ,Retrospective Studies ,business.industry ,Proportional hazards model ,Hazard ratio ,Gastroenterology ,Cancer ,General Medicine ,Esophageal cancer ,medicine.disease ,Confidence interval ,Esophagectomy ,Survival Rate ,medicine.anatomical_structure ,030220 oncology & carcinogenesis ,Lymph Node Excision ,Original Article ,Lymph Nodes ,Radiology ,business - Abstract
SUMMARY There is debate surrounding the appropriate threshold for lymph node harvest during esophagectomy in patients with esophageal cancer, specifically for those receiving preoperative radiation. The purpose of this study was to determine the impact of lymph node yield on survival in patients receiving preoperative chemoradiation for esophageal cancer. The National Cancer Database (NCDB) was utilized to identify patients with esophageal cancer that received preoperative radiation. The cohort was divided into patients undergoing minimal ( 0.05). After adjustment using Cox regression, extensive lymph node yield was associated with survival (hazard ratio 0.80, confidence interval 0.66–0.98, P = 0.03). This study suggests that extensive lymph node yield is advantageous for patients with esophageal cancer undergoing esophagectomy following induction therapy. This most likely reflects improved diagnosis and staging with extensive yield.
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- 2020
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15. 4031 Heart Transplant Candidates Listed at Low First-Offer Organ Acceptance Rate Centers are More Likely to Die Waiting
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Jacob N. Schroder, Matthew G. Hartwig, Hui-Jie Lee, Congwen Zhao, Michael S. Mulvihill, Chetan B. Patel, Christopher B. Granger, Maragatha Kuchibhatla, and Ashley Y. Choi
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Transplantation ,business.industry ,Acceptance rate ,Organ acceptance ,Significant difference ,Medicine ,Population study ,Cumulative incidence ,Retrospective cohort study ,General Medicine ,business ,Logistic regression ,Demography - Abstract
OBJECTIVES/GOALS: We sought to examine: 1) variability in center acceptance patterns for heart allografts offered to the highest-priority candidates, 2) impact of this acceptance behavior on candidate survival, and 3) post-transplantation outcomes in candidates who accepted first rank offer vs. previously declined offer. METHODS/STUDY POPULATION: In this retrospective cohort study, the US national transplant registry was queried for all match runs of adult candidates listed for isolated heart transplantation between 2007-2017. We examined center acceptance rates for heart allografts offered to the highest-priority candidates and accounted for covariates in multivariable logistic regression. Competing risks analysis was performed to assess the relationship between center acceptance rate and waitlist mortality. Post-transplantation outcomes (patient survival and graft failure) between candidates who accepted their first-rank offers vs those who accepted previously declined offers were compared using Fine-Gray subdistribution hazards model. RESULTS/ANTICIPATED RESULTS: Among 19,703 unique organ offers, 6,302 (32%) were accepted for first-ranked candidates. After adjustment for donor, recipient, and geographic covariates, transplant centers varied markedly in acceptance rates (12%-62%) of offers made to first-ranked candidates. Lowest acceptance rate centers (
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- 2020
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16. Predictors of Older Donor Lung Use: Are We Too Good at Saying No?
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Matthew G. Hartwig, John C. Haney, Vignesh Raman, Samantha E. Halpern, Jacob A. Klapper, Ashley Y. Choi, and Oliver K. Jawitz
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Pulmonary and Respiratory Medicine ,Organ procurement organization ,Adult ,Male ,medicine.medical_specialty ,medicine.medical_treatment ,Population ,030204 cardiovascular system & hematology ,Article ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,Medicine ,Lung transplantation ,Humans ,Transplantation, Homologous ,education ,Aged ,Proportional Hazards Models ,education.field_of_study ,business.industry ,Proportional hazards model ,Hazard ratio ,Age Factors ,Middle Aged ,Confidence interval ,Tissue Donors ,Transplantation ,Logistic Models ,030228 respiratory system ,Donation ,Surgery ,Female ,Cardiology and Cardiovascular Medicine ,business ,Lung Transplantation - Abstract
Background Patterns of use of older donor lungs within this previously underused donor population are poorly characterized. This study examined factors associated with the use of older donor lung allografts and factors associated with survival in recipients of these lungs. Methods Adult donors in the United Network for Organ Sharing registry who donated 1 or more organs for transplantation between 2006 and 2018 were analyzed and stratified into older (age >55 years) and younger (age ≤55 years) cohorts. Multivariable logistic and Cox regression were used to identify factors associated with transplantation of older donor lungs and factors associated with survival, respectively. Results Overall, 202,477 donors were included and stratified by age (older, 40,406 [20%]; younger, 162,071 [80%]). Compared with younger donors, older donors had an increased rate of consent for donation not requested by organ procurement organizations (7.5% vs 1.7%). Donor factors significantly associated with decreased lung use included male sex, increasing donor age, black race, Hispanic ethnicity, cigarette use, cocaine use, donation after circulatory death status, and PaO2/FiO2 (P/F ratio) lower than 350. In recipients of older donor lungs, increasing donor age (hazard ratio [HR], 1.03; 95% confidence interval [CI], 1.01, 1.05), recipient age 47 years or older (HR 1.03; 95% CI, 1.02, 1.04), and male sex (HR, 1.19; 95% CI, 1.02, 1.39) portended worse survival. Conclusions Barriers in consenting practices, concerns about organ function, and recipient survival prevent the widespread use of aged allografts for lung transplantation. Better understanding of factors associated with worse outcomes of older donors and modification of organ procurement organization consenting practices may increase the use of these higher-risk donor organs.
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- 2019
17. B cells in transplant tolerance and rejection: friends or foes?
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Zachary W. Fitch, Ashley Y. Choi, Jean Kwun, Robin Schmitz, Stuart J. Knechtle, Paul M. Schroder, and Annette M. Jackson
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Graft Rejection ,medicine.medical_specialty ,medicine.medical_treatment ,Antigen presentation ,030230 surgery ,Organ transplantation ,Article ,03 medical and health sciences ,0302 clinical medicine ,Antigen ,Isoantibodies ,medicine ,Humans ,B cell ,Transplantation ,B-Lymphocytes ,biology ,Mechanism (biology) ,business.industry ,Organ Transplantation ,medicine.anatomical_structure ,Cytokine ,Immunology ,biology.protein ,030211 gastroenterology & hepatology ,Transplantation Tolerance ,Antibody ,business - Abstract
Our understanding of the role of B cells in organ transplantation remains incomplete and continues to grow. The majority of research has focused on the detrimental role of antibodies that drive the development of pathogenesis of the transplanted organ. However, it has been shown that not all donor-specific antibodies are harmful and in some circumstances can even promote tolerance through the mechanism of accommodation. Furthermore, B cells can have effects on transplanted organs through their interaction with T cells, namely antigen presentation, cytokine production, and costimulation. More recently, the role and importance of Bregs was introduced to the field of transplantation. Due to this functional and ontogenetic heterogeneity, targeting B cells in transplantation may bring undesired immunologic side effects including increased rejection. Therefore, the selective control of B cells that contribute to the humoral response against donor antigens will continue to be an important and challenging area of research and potentially lead to improved long-term transplant outcomes.
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- 2019
18. The past, present, and future of costimulation blockade in organ transplantation
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Jean Kwun, Zachary W. Fitch, Robin Schmitz, Ashley Y. Choi, Stuart J. Knechtle, and Paul M. Schroder
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Graft Rejection ,medicine.medical_specialty ,Swine ,T cell ,Transplantation, Heterologous ,Heterologous ,030230 surgery ,Bioinformatics ,Belatacept ,Organ transplantation ,Article ,Abatacept ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Immunology and Allergy ,Animals ,Humans ,Transplantation ,Costimulation blockade ,business.industry ,Organ Transplantation ,Kidney Transplantation ,medicine.anatomical_structure ,030211 gastroenterology & hepatology ,Graft survival ,business ,Solid organ transplantation ,Immunosuppressive Agents ,medicine.drug - Abstract
PURPOSE OF REVIEW: Manipulating costimulatory signals has been shown to alter T cell responses and prolong graft survival in solid organ transplantation. Our understanding of and ability to target various costimulation pathways continues to evolve. RECENT FINDINGS: Since the approval of belatacept in kidney transplantation, many additional biologics have been developed targeting clinically relevant costimulation signaling axes including CD40-CD40L, inducible costimulator-inducible costimulator ligand (ICOS-ICOSL), and OX40-OX40L. Currently, the effects of costimulation blockade on posttransplant humoral responses, tolerance induction, and xenotransplantation are under active investigation. Here, we will discuss these pathways as well as preclinical and clinical outcomes of biologics targeting these pathways in organ transplantation. SUMMARY: Targeting costimultion is a promising approach for not only controlling T cell but also B cell responses. Consequently, costimulation blockade shows considerable potential for improving outcomes in antibody-mediated rejection and xenotransplantation.
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- 2019
19. Variability in donor organ offer acceptance and lung transplantation survival
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Matthew G. Hartwig, Michael S. Mulvihill, Muath Bishawi, Hui J. Lee, Morgan L. Cox, Jacob A. Klapper, Jeremy M. Weber, Babatunde A. Yerokun, Ashley Y. Choi, and Maragatha Kuchibhatla
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Pulmonary and Respiratory Medicine ,Adult ,Male ,Tissue and Organ Procurement ,Waiting Lists ,medicine.medical_treatment ,030230 surgery ,Logistic regression ,Article ,Donor Selection ,03 medical and health sciences ,0302 clinical medicine ,Risk Factors ,medicine ,Lung transplantation ,Humans ,Cumulative incidence ,Registries ,Risk factor ,Retrospective Studies ,Transplantation ,business.industry ,Hazard ratio ,Retrospective cohort study ,Fixed effects model ,Middle Aged ,Confidence interval ,Tissue Donors ,Transplant Recipients ,United States ,Survival Rate ,030228 respiratory system ,Surgery ,Female ,Cardiology and Cardiovascular Medicine ,business ,Demography ,Follow-Up Studies ,Lung Transplantation - Abstract
BACKGROUND Lung transplantation offers a survival benefit for patients with end-stage lung disease. When suitable donors are identified, centers must accept or decline the offer for a matched candidate on their waitlist. The degree to which variability in per-center offer acceptance practices impacts candidate survival is not established. The purpose of this study was to determine the degree of variability in per-center rates of lung transplantation offer acceptance and to ascertain the associated contribution to observed differences in per-center waitlist mortality. METHODS We performed a retrospective cohort study of candidates waitlisted for lung transplantation in the US using registry data. Logistic regression was fit to assess the relationship of offer acceptance with donor, candidate, and geographic factors. Listing center was evaluated as a fixed effect to determine the adjusted per-center acceptance rate. Competing risks analysis employing the Fine-Gray model was undertaken to establish the relationship between adjusted per-center acceptance and waitlist mortality. RESULTS Of 15,847 unique organ offers, 4,735 (29.9%) were accepted for first-ranked candidates. After adjustment for important covariates, transplant centers varied markedly in acceptance rate (9%–67%). Higher cumulative incidence of 1-year waitlist mortality was associated with lower acceptance rate. For every 10% increase in adjusted center acceptance rate, the risk of waitlist mortality decreased by 36.3% (sub-distribution hazard ratio 0.637; 95% confidence interval 0.592–0.685). CONCLUSIONS Variability in center-level behavior represents a modifiable risk factor for waitlist mortality in lung transplantation. Further intervention is needed to standardize center-level offer acceptance practices and minimize waitlist mortality.
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- 2019
20. Impact of Donor Brain Death Duration on Outcomes After Lung Transplantation
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Matthew G. Hartwig, Carrie B. Moore, Michael S. Mulvihill, Vignesh Raman, Ashley Y. Choi, Jacob A. Klapper, Oliver K. Jawitz, and Yaron D. Barac
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Pulmonary and Respiratory Medicine ,Adult ,Male ,medicine.medical_specialty ,Brain Death ,Time Factors ,Tissue and Organ Procurement ,medicine.medical_treatment ,Bronchiolitis obliterans ,Primary Graft Dysfunction ,030204 cardiovascular system & hematology ,03 medical and health sciences ,0302 clinical medicine ,Postoperative Complications ,Interquartile range ,Internal medicine ,medicine ,Lung transplantation ,Humans ,Survival rate ,Aged ,Retrospective Studies ,business.industry ,Donor selection ,Hazard ratio ,Odds ratio ,Middle Aged ,medicine.disease ,Survival Rate ,Treatment Outcome ,030228 respiratory system ,Surgery ,Female ,Cardiology and Cardiovascular Medicine ,business ,Lung Transplantation - Abstract
Donor brain death duration (BDD) may impact posttransplant graft function and survival in lung transplant.We queried the 2007 to 2018 United Network for Organ Sharing Registry for adult recipients undergoing first-time isolated lung transplant. Cox proportional hazard modeling with splines enabled identification of 3 donor brain death intervals for subsequent analysis: short (24 hours), reference (24-60 hours), and long (60 hours). The primary outcome was posttransplant survival.In total, 19,721 donors and recipients met inclusion criteria. Median time from donor brain death until cross-clamp was 36.6 hours (interquartile range, 19.5). Unadjusted overall survival between cohorts was equivalent (log-rank P = .42); however, longer BDD was associated with improved bronchiolitis obliterans syndrome (BOS)-free survival (log-rank P.001). On multivariable Cox proportional hazards regression, BDD was not associated with recipient survival (P.05). Similarly, logistic regression did not identify an independent association between BDD and primary graft dysfunction (P .05). Increased BDD was, however, associated with a decreased risk of acute rejection (long vs reference; adjusted odds ratio, 0.78; 95% confidence interval, 0.64-0.94) and improved BOS-free survival (long vs reference; adjusted hazard ratio, 0.88; 95% confidence interval, 0.81-0.96).Donor BDD is not associated with posttransplant survival or primary graft dysfunction. Long donor BDD, however, is associated with a decreased risk for acute rejection and improved BOS-free survival. Therefore, lung allografts from donors with a prolonged length of time from brain death until explant should not be viewed less favorably by donor selection centers.
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- 2019
21. Predictors of nonuse of donation after circulatory death lung allografts
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Oliver K. Jawitz, Samantha E. Halpern, Yaron D. Barac, Matthew G. Hartwig, Ashley Y. Choi, Michael S. Mulvihill, Vignesh Raman, and Jacob A. Klapper
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Pulmonary and Respiratory Medicine ,United Network for Organ Sharing ,Organ procurement organization ,medicine.medical_specialty ,business.industry ,medicine.medical_treatment ,Primary Graft Dysfunction ,Odds ratio ,030204 cardiovascular system & hematology ,Hypoxemia ,Transplantation ,03 medical and health sciences ,0302 clinical medicine ,030228 respiratory system ,Donation ,medicine ,Lung transplantation ,Surgery ,medicine.symptom ,Cardiology and Cardiovascular Medicine ,Intensive care medicine ,business - Abstract
Central Message: Utilization of donation after circulatory death lungs can be improved with appropriate interventions. International guidelines should be developed to facilitate improved organ recovery. (185/200 characters) Perspective Statement: Waitlist mortality is currently at an all-time high in lung transplantation in the United States. Donation after circulatory death lungs have shown promise in expanding the donor pool, yet the US lags behind several other countries in utilizing these organs. With appropriate interventions such as ex-vivo lung perfusion, many factors that influence these practice patterns can potentially be improved. (402/405 characters); Abstract 250/250 Objective: Despite growing evidence of comparable outcomes in recipients of donation-after-circulatory-death and donation-after-brain-death donor lungs, donation-after-circulatory-death allografts continue to be underutilized nationally. We examined predictors of non-utilization. Methods: All donors who donated at least one organ for transplantation between 2005-2019 were identified in the United Network of Organ Sharing registry and stratified by donation type. The primary outcome of interest was utilization of pulmonary allografts. Organ disposition and refusal reasons were evaluated. Multivariable regression modeling was used to assess the relationship between donor factors and utilization. Results: A total of 15,458 donation-after-circulatory-death donors met inclusion criteria. Of 30,916 lungs, 3.7% (1,158) were utilized for transplantation and 72.8% were discarded primarily due to poor organ function. Consent was not requested in 8.4% of donation-after-circulatory-death offers with donation-after-circulatory-death being the leading reason (73.4%). Non-utilization was associated with smoking history (p 50 (0.75, p=0.031). Recent transplant era was associated with significantly increased utilization (AOR 2.28, p Conclusions: Non-transplantation of donation-after-circulatory-death lungs was associated with potentially modifiable pre-donation factors, including organ procurement organizations’ consenting behavior, and donor factors, including hypoxemia. Interventions to increase consent and standardize donation-after-circulatory-death donor management, including selective use of ex-vivo lung perfusion in the setting of hypoxemia, may increase utilization and the donor pool.
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- 2021
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22. CARFILZOMIB AND LULIZUMAB-BASED DESENSITIZATION PROLONGS ALLOGRAFT SURVIVAL IN SENSITIZED NON-HUMAN PRIMATES KIDNEY TRANSPLANTATION MODEL
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Zachary W. Fitch, Alton B. Farris, Robin Schmitz, Mingqing Song, Jean Kwun, F. Leopardi, Andrew S. Barbas, Stuart J. Knechtle, Janghoon Yoon, Brian Ezekian, Bradley H. Collins, Paul M. Schroder, and Ashley Y. Choi
- Subjects
Transplantation ,chemistry.chemical_compound ,chemistry ,business.industry ,medicine.medical_treatment ,Allograft survival ,Medicine ,Pharmacology ,business ,medicine.disease ,Carfilzomib ,Kidney transplantation ,Desensitization (medicine) - Published
- 2020
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23. BLOCKING COMPLEMENT C3 IN A SENSITIZED NONHUMAN PRIMATE MODEL OF KIDNEY TRANSPLANTATION
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Edimara S. Reis, Gowthami M. Arepally, Zachary W. Fitch, Robin Schmitz, Alton B. Farris, Sanjay Khandelwal, Paul M. Schroder, Stuart J. Knechtle, Janghoon Yoon, John D. Lambris, Ashley Y. Choi, Jean Kwun, and Miriam Manook
- Subjects
Transplantation ,business.industry ,Blocking (radio) ,Immunology ,Medicine ,business ,medicine.disease ,Nonhuman primate ,Kidney transplantation ,Complement (complexity) - Published
- 2020
- Full Text
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24. 4139 Risk Aversion in Lung Transplantation: Organ Procurement Organizations Differ in Willingness to Pursue Non-ideal Donor Organs
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Samantha E. Halpern, Oliver K. Jawitz, John C. Haney, Sarah B. Peskoe, Alec McConnell, Jacob A. Klapper, Vignesh Raman, Matthew G. Hartwig, and Ashley Y. Choi
- Subjects
Organ procurement ,Ideal (set theory) ,Actuarial science ,business.industry ,medicine.medical_treatment ,medicine ,Lung transplantation ,Risk aversion (psychology) ,General Medicine ,business - Abstract
OBJECTIVES/GOALS: Lung transplant (LTx) candidates benefit from use of non-ideal donor organs. Each organ procurement organization (OPO) defines “acceptable” donor organs introducing unmeasured variation in donor pursuit. We characterized non-ideal donor pursuit among OPOs to identify drivers of risk aversion in LTx. METHODS/STUDY POPULATION: We queried the UNOS registry for adult donors who donated ≥1 organ for transplantation from 12/2007-12/2018. Non-ideal donors were those with any of age>50, smoking history ≥20 pack-years, PaO2/FiO2 (P/F) ratioFigure). Of 5 non-ideal characteristics, DCD and IRD status were associated with the most and least risk aversion, respectively. Non-ideal donor pursuit was strongly correlated with overall donor pursuit (r = 0.99). On adjusted analysis, older age (OR 0.15, 95% CI 0.13-0.16), smoking history (OR 0.38, 95% CI 0.34-0.44), low P/F ratio (OR 0.12, 95% CI 0.11-0.14), and DCD status (OR 0.04, 95% CI 0.03-0.04) were all independently associated with significant risk aversion, corresponding to decreased rates of donor pursuit. DISCUSSION/SIGNIFICANCE OF IMPACT: OPOs differ in their levels of risk aversion in LTx and risk aversion is not uniform across selected categories of non-ideal lung donor. Consideration of new OPO performance metrics that encourage the pursuit of non-ideal lung donors is warranted.
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- 2020
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25. Transplant Center Variability in Organ Offer Acceptance and Mortality Among US Patients on the Heart Transplant Waitlist
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Michael S. Mulvihill, Hui-Jie Lee, Congwen Zhao, Ashley Y. Choi, Matthew G. Hartwig, Jacob N. Schroder, Maragatha Kuchibhatla, Chetan B. Patel, and Christopher B. Granger
- Subjects
Heart transplantation ,medicine.medical_specialty ,business.industry ,medicine.medical_treatment ,Hazard ratio ,Retrospective cohort study ,030204 cardiovascular system & hematology ,Transplantation ,03 medical and health sciences ,0302 clinical medicine ,Cohort ,Emergency medicine ,medicine ,Risk of mortality ,Cumulative incidence ,030212 general & internal medicine ,Young adult ,Cardiology and Cardiovascular Medicine ,business - Abstract
Importance Under the current Centers for Medicare & Medicaid Services guidelines, there is incentivization to optimize posttransplant outcomes regardless of mortality among patients on the waitlist and transplant rates; few data exist with regard to transplant center acceptance practices and survival to heart transplant. Objectives To evaluate the extent of variability in organ acceptance practices in the US and whether this center-level behavior is associated with heart transplant candidate survival. Design, Setting, and Participants In this retrospective cohort study, the US National Transplant Registry was queried for all match runs of adult candidates listed for isolated heart transplant between May 1, 2007, and March 31, 2017. Data analysis was conducted from October 30, 2018, to May 1, 2019. The final cohort included 93 transplant centers, 19 703 donors, and 9628 candidates. Main Outcomes and Measures Center acceptance rates for heart allografts offered to the highest-priority candidates, association between center acceptance rate and mortality among patients on the waitlist, and posttransplant outcomes between candidates who accepted their first-rank offers vs those who accepted previously declined offers. Results Among 19 703 unique organ offers, 6302 hearts (32.0%) were accepted for first-rank candidates. After adjustment for donor, candidate, and geographic covariates, transplant centers varied in acceptance rates (12.3%-61.5%) of offers made to first-rank candidates. Higher acceptance rates were associated with lower cumulative incidence of 1-year mortality among patients on the waitlist. For every 10% increase in adjusted center acceptance rate, the risk of mortality decreased by 27% (subdistribution hazard ratio, 0.73; 95% CI, 0.67-0.80). No statistically significant difference was observed in 5-year adjusted posttransplant patient survival (adjusted hazard ratio, 1.02; 95% CI, 0.94-1.11) and graft failure (subdistribution hazard ratio; 0.95; 95% CI, 0.83-1.09) between hearts accepted at the first-rank compared with lower-rank positions. Conclusions and Relevance Variability in heart allograft acceptance rates appears to exist among transplant centers, with candidates listed at lower acceptance rate centers being more likely to experience mortality while on the waitlist. Comparable posttransplant survival suggests that allografts that were declined as a first offer perform as well as those that were accepted at their first offer. These findings suggest that organ acceptance rate or time to transplant from being added to the waitlist may be an additional measure of heart transplant program performance.
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- 2020
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26. Tu1363 SAFETY AND EFFICACY OF AN IMPLANTABLE DEVICE FOR MANAGEMENT OF GASTROESOPHAGEAL REFLUX IN LUNG TRANSPLANT RECIPIENTS
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Matthew G. Hartwig, Hai Salfity, Oliver K. Jawitz, Samantha E. Halpern, Vignesh Raman, Aryaman Gupta, Jacob A. Klapper, John C. Haney, and Ashley Y. Choi
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medicine.medical_specialty ,Lung ,medicine.anatomical_structure ,Hepatology ,business.industry ,Internal medicine ,Gastroenterology ,Reflux ,Medicine ,business - Published
- 2020
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27. Outcomes After Extracorporeal Right Ventricular Assist Device Combined With Durable Left Ventricular Assist Device Support
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Muath Bishawi, Ashley Y. Choi, Chetan B. Patel, Carmelo A. Milano, Patrick Winterton, Mani A. Daneshmand, Joseph G. Rogers, J. Mauricio Del Rio, Maziar Khorsandi, Omar Bouamra, and Jacob N. Schroder
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Pulmonary and Respiratory Medicine ,Adult ,Male ,medicine.medical_specialty ,medicine.medical_treatment ,Prosthesis Design ,Extracorporeal ,Young Adult ,Postoperative Complications ,Medicine ,Humans ,Young adult ,Adverse effect ,Aged ,Retrospective Studies ,Heart Failure ,business.industry ,Mortality rate ,Retrospective cohort study ,Middle Aged ,equipment and supplies ,Surgery ,Right Ventricular Assist Device ,Treatment Outcome ,Ventricular assist device ,Cohort ,Female ,Heart-Assist Devices ,Cardiology and Cardiovascular Medicine ,business - Abstract
Background Right heart failure occurs in 9% to 44% of left ventricular assist device (LVAD) implants, of which less than 10% require right ventricular assist device (RVAD) support either concurrently with the LVAD or staged, as a delayed procedure. We have reported our outcomes based on whether the RVAD was placed concurrently or staged. Methods Clinical data were obtained from the Duke University Medical Center database. The study focused on all consecutive adult patients who received continuous flow LVAD with either concurrent or staged (within 7 days) extracorporeal, temporary RVAD, between October 2007 and October 2017. Adverse event profiles and ability to wean from RVAD were compared between these two groups. Results Overall, 43 patients required an extracorporeal RVAD; 67% (n = 29) were implanted concurrently and 33% (n = 14) were implanted as staged after the LVAD. In all, 67% of patients (n = 29) could be weaned to an isolated LVAD. The 30-day, inhospital, and total mortality rates for our cohort were 14%, 28%, and 51% respectively. The mortality rate in the study period for the staged implants was 71% versus 45% for the concurrent implants (p = 0.101). In addition, staged RVAD implantation carried a significantly higher rate of postoperative renal failure (64% versus 28%, p = 0.044). Conclusions There was a low incidence of need for RVAD in our cohort. The majority could be weaned to an isolated LVAD. Morbidity and mortality rates of this mode of biventricular support remain high. Early institution of RVAD support was associated with reduced rates of post-LVAD renal failure rates.
- Published
- 2018
28. 3518 Bowel Ischemia after Continuous Flow Ventricular Assist Device Therapy: A Single Center Analysis
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Jacob N. Schroder, Suresh M. Agarwal, Carmelo A. Milano, Jatin Anand, Muath Bishawi, Ashley Y. Choi, and Mani A. Daneshmand
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medicine.medical_specialty ,medicine.diagnostic_test ,business.industry ,medicine.medical_treatment ,Colonoscopy ,Retrospective cohort study ,General Medicine ,Single Center ,Science and Health Policy/Ethics/Health Impacts/Outcomes Research ,Surgery ,Interquartile range ,Ventricular assist device ,medicine ,Renal replacement therapy ,Complication ,business ,Destination therapy - Abstract
OBJECTIVES/SPECIFIC AIMS: The purpose of the study was to describe patient characteristics associated with subsequent development of bowel ischemia. Primary outcomes were survival to discharge, 30-day and 1-year survival in patients with LVAD who subsequently develop bowel ischemia. Secondary outcomes included characteristics of patients who survive to discharge after bowel ischemia and those who do not. These included markers of patient condition prior to surgical/endoscopic intervention such as lactate levels, ICU admission, ventilator dependence, vasopressor and renal replacement requirements, as well as presence of sepsis. Of these, we predicted that lactate levels and white blood cell count would be significantly elevated pre- and post-operatively in patients who do not recover from bowel ischemic event. We used Mann-Whitney U Test to examine lactate levels between the two groups as our sample size was
- Published
- 2019
- Full Text
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29. Use of Single-Site Functionalized PEG-Dendrons to Prepare Gene Vectors that Penetrate Human Mucus Barriers
- Author
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Wojciech G. Lesniak, Benjamin S. Schuster, Jung Soo Suk, Liudimila Cebotaru, Nicholas J. Boylan, Rangaramanujam M. Kannan, Tao Yu, Minyoung Hwangbo, Anthony J. Kim, Pichet Adstamongkonkul, Ashley Y. Choi, Joon Seok Oh, and Justin Hanes
- Subjects
Drug ,Dendrimers ,media_common.quotation_subject ,Genetic enhancement ,Genetic Vectors ,Gene delivery ,Cystic fibrosis ,Catalysis ,Article ,Polyethylene Glycols ,Dendrimer ,PEG ratio ,medicine ,Polyamines ,Humans ,Respiratory system ,media_common ,Chemistry ,Gene Transfer Techniques ,General Medicine ,General Chemistry ,DNA ,medicine.disease ,Mucus ,Molecular biology ,Biophysics ,Nanoparticles - Abstract
Protective mucus layers serve as the body’s first line of defense at exposed surfaces of the eyes and respiratory, gastrointestinal, and cervicovaginal tracts. These highly viscoelastic and adhesive mucus gels trap most foreign pathogens and environmental ultrafine particles, which are then removed by mucus clearance mechanisms[1] (on the order of seconds to a few hours, depending on anatomical site). However, mucus also immobilizes and rapidly clears therapeutic nanoparticles, including synthetic drug carriers,[2] and clinically tested viral[3] and nonviral gene vectors[4] and, therefore, represents a critical obstacle to localized drug and gene delivery at mucosal surfaces for the treatment of a variety of diseases.[1b]
- Published
- 2013
30. 4031 Heart Transplant Candidates Listed at Low First-Offer Organ Acceptance Rate Centers are More Likely to Die Waiting
- Author
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Ashley Y Choi, Michael S. Mulvihill, Hui-Jie Lee, Congwen Zhao, Maragatha Kuchibhatla, Jacob N. Schroder, Chetan B. Patel, Christopher B. Granger, and Matthew G. Hartwig
- Subjects
Medicine - Abstract
OBJECTIVES/GOALS: We sought to examine: 1) variability in center acceptance patterns for heart allografts offered to the highest-priority candidates, 2) impact of this acceptance behavior on candidate survival, and 3) post-transplantation outcomes in candidates who accepted first rank offer vs. previously declined offer. METHODS/STUDY POPULATION: In this retrospective cohort study, the US national transplant registry was queried for all match runs of adult candidates listed for isolated heart transplantation between 2007-2017. We examined center acceptance rates for heart allografts offered to the highest-priority candidates and accounted for covariates in multivariable logistic regression. Competing risks analysis was performed to assess the relationship between center acceptance rate and waitlist mortality. Post-transplantation outcomes (patient survival and graft failure) between candidates who accepted their first-rank offers vs those who accepted previously declined offers were compared using Fine-Gray subdistribution hazards model. RESULTS/ANTICIPATED RESULTS: Among 19,703 unique organ offers, 6,302 (32%) were accepted for first-ranked candidates. After adjustment for donor, recipient, and geographic covariates, transplant centers varied markedly in acceptance rates (12%-62%) of offers made to first-ranked candidates. Lowest acceptance rate centers (
- Published
- 2020
- Full Text
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31. 3518 Bowel Ischemia after Continuous Flow Ventricular Assist Device Therapy: A Single Center Analysis
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Ashley Y Choi, Jatin Anand, Muath Bishawi, Mani A. Daneshmand, Jacob N. Schroder, Suresh M. Agarwal, and Carmelo A. Milano
- Subjects
Medicine - Abstract
OBJECTIVES/SPECIFIC AIMS: The purpose of the study was to describe patient characteristics associated with subsequent development of bowel ischemia. Primary outcomes were survival to discharge, 30-day and 1-year survival in patients with LVAD who subsequently develop bowel ischemia. Secondary outcomes included characteristics of patients who survive to discharge after bowel ischemia and those who do not. These included markers of patient condition prior to surgical/endoscopic intervention such as lactate levels, ICU admission, ventilator dependence, vasopressor and renal replacement requirements, as well as presence of sepsis. Of these, we predicted that lactate levels and white blood cell count would be significantly elevated pre- and post-operatively in patients who do not recover from bowel ischemic event. We used Mann-Whitney U Test to examine lactate levels between the two groups as our sample size was
- Published
- 2019
- Full Text
- View/download PDF
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