Browsing by Author "Anderson, Michaela"

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    Contemporary trends in PGD incidence, outcomes, and therapies
    (Elsevier, 2022) Cantu, Edward; Diamond, Joshua M.; Cevasco, Marisa; Suzuki, Yoshi; Crespo, Maria; Clausen, Emily; Dallara, Laura; Ramon, Christian V.; Harmon, Michael T.; Bermudez, Christian; Benvenuto, Luke; Anderson, Michaela; Wille, Keith M.; Weinacker, Ann; Dhillon, Gundeep S.; Orens, Jonathan; Shah, Pali; Merlo, Christian; Lama, Vibha; McDyer, John; Snyder, Laurie; Palmer, Scott; Hartwig, Matt; Hage, Chadi A.; Singer, Jonathan; Calfee, Carolyn; Kukreja, Jasleen; Greenland, John R.; Ware, Lorraine B.; Localio, Russel; Hsu, Jesse; Gallop, Robert; Christie, Jason D.; Medicine, School of Medicine
    Background: We sought to describe trends in extracorporeal membrane oxygenation (ECMO) use, and define the impact on PGD incidence and early mortality in lung transplantation. Methods: Patients were enrolled from August 2011 to June 2018 at 10 transplant centers in the multi-center Lung Transplant Outcomes Group prospective cohort study. PGD was defined as Grade 3 at 48 or 72 hours, based on the 2016 PGD ISHLT guidelines. Logistic regression and survival models were used to contrast between group effects for event (i.e., PGD and Death) and time-to-event (i.e., death, extubation, discharge) outcomes respectively. Both modeling frameworks accommodate the inclusion of potential confounders. Results: A total of 1,528 subjects were enrolled with a 25.7% incidence of PGD. Annual PGD incidence (14.3%-38.2%, p = .0002), median LAS (38.0-47.7 p = .009) and the use of ECMO salvage for PGD (5.7%-20.9%, p = .007) increased over the course of the study. PGD was associated with increased 1 year mortality (OR 1.7 [95% C.I. 1.2, 2.3], p = .0001). Bridging strategies were not associated with increased mortality compared to non-bridged patients (p = .66); however, salvage ECMO for PGD was significantly associated with increased mortality (OR 1.9 [1.3, 2.7], p = .0007). Restricted mean survival time comparison at 1-year demonstrated 84.1 days lost in venoarterial salvaged recipients with PGD when compared to those without PGD (ratio 1.3 [1.1, 1.5]) and 27.2 days for venovenous with PGD (ratio 1.1 [1.0, 1.4]). Conclusions: PGD incidence continues to rise in modern transplant practice paralleled by significant increases in recipient severity of illness. Bridging strategies have increased but did not affect PGD incidence or mortality. PGD remains highly associated with mortality and is increasingly treated with salvage ECMO.
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    Obesity-related IL-18 Impairs T-Regulatory Cell Function and Promotes Lung Ischemia–Reperfusion Injury
    (American Thoracic Society, 2021) Akimova, Tatiana; Zhang, Tianyi; Christensen, Lanette M.; Wang, Zhonglin; Han, Rongxiang; Negorev, Dmitry; Samanta, Arabinda; Sasson, Isaac E.; Gaddapara, Trivikram; Jiao, Jing; Wang, Liqing; Bhatti, Tricia R.; Levine, Matthew H.; Diamond, Joshua M.; Beier, Ulf H.; Simmons, Rebecca A.; Cantu, Edward; Wilkes, David S.; Lederer, David J.; Anderson, Michaela; Christie, Jason D.; Hancock, Wayne W.; Medicine, School of Medicine
    Rationale: Primary graft dysfunction (PGD) is a severe form of acute lung injury, leading to increased early morbidity and mortality after lung transplant. Obesity is a major health problem, and recipient obesity is one of the most significant risk factors for developing PGD. Objectives: We hypothesized that T-regulatory cells (Tregs) are able to dampen early ischemia–reperfusion events and thereby decrease the risk of PGD, whereas that action is impaired in obese recipients. Methods: We evaluated Tregs, T cells, and inflammatory markers, plus clinical data, in 79 lung transplant recipients and 41 liver or kidney transplant recipients and studied two groups of mice on a high-fat diet (HFD), which did (“inflammatory” HFD) or did not (“healthy” HFD) develop low-grade inflammation with decreased Treg function. Measurements and Main Results: We identified increased levels of IL-18 as a previously unrecognized mechanism that impairs Tregs’ suppressive function in obese individuals. IL-18 decreases levels of FOXP3, the key Treg transcription factor, decreases FOXP3 di- and oligomerization, and increases the ubiquitination and proteasomal degradation of FOXP3. IL-18–treated Tregs or Tregs from obese mice fail to control PGD, whereas IL-18 inhibition ameliorates lung inflammation. The IL-18–driven impairment in Tregs’ suppressive function before transplant was associated with an increased risk and severity of PGD in clinical lung transplant recipients. Conclusions: Obesity-related IL-18 induces Treg dysfunction that may contribute to the pathogenesis of PGD. Evaluation of Tregs’ suppressive function together with evaluation of IL-18 levels may serve as a screening tool to identify obese individuals with an increased risk of PGD before transplant.