Publications by authors named "David M Sayah"

Clinical outcomes after lung transplantation, a life-saving therapy for patients with end-stage lung diseases, are limited by primary graft dysfunction (PGD). PGD is an early form of acute lung injury with no specific pharmacologic therapies. Here, we present a large multicenter study of plasma and bronchoalveolar lavage (BAL) samples collected on the first posttransplant day, a critical time for investigations of immune pathways related to PGD.

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The medical care of patients awaiting lung transplantation is complex and requires the treatment of active medical conditions, including lung disease, while at the same time maintaining candidacy for transplantation. Some medications that would otherwise be considered routine may create undesirable challenges or complications in the perioperative setting. Therefore, a comprehensive assessment of the risks and benefits of these medications must take into account both their potential utility in managing a patient's current disease state, as well as the risks of compromising postlung transplant outcomes.

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Background: Chronic lung allograft dysfunction (CLAD) phenotype determines prognosis and may have therapeutic implications. Despite the clarity achieved by recent consensus statement definitions, their reliance on radiologic interpretation introduces subjectivity. The Center for Computer Vision and Imaging Biomarkers at the University of California, Los Angeles (UCLA) has established protocols for chest high-resolution computed tomography (HRCT)-based computer-aided quantification of both interstitial disease and air-trapping.

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Despite the common detection of non-donor specific anti-HLA antibodies (non-DSAs) after lung transplantation, their clinical significance remains unclear. In this retrospective single-center cohort study of 325 lung transplant recipients, we evaluated the association between donor-specific HLA antibodies (DSAs) and non-DSAs with subsequent CLAD development. DSAs were detected in 30% of recipients and were associated with increased CLAD risk, with higher HRs for both de novo and high MFI (>5000) DSAs.

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Article Synopsis
  • - Sweet's Syndrome (SS) is an inflammatory skin condition characterized by the presence of neutrophils and is a type of neutrophilic dermatosis.
  • - There are fewer than 50 documented cases of respiratory complications related to SS, but this article discusses a unique case involving lung transplantation (LT).
  • - The study highlights the clinical journey of the first patient who underwent LT for pulmonary SS and suggests that the lung disease may recur in the transplanted organ.
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The association of autoimmune disease (AI) with transplant-free survival in the setting of Group 3 pulmonary hypertension and pulmonary fibrosis remains unclear. We report cases of severe pulmonary hypertension (mean pulmonary artery pressure ≥35 mmHg right ventricular dysfunction) and extensive pulmonary fibrosis after pulmonary arterial hypertension-specific therapy. We used multivariate regression to determine the clinical variables associated with transplant-free survival.

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Article Synopsis
  • The immune system typically fights off pathogens while ignoring the body’s own signals, but during lung transplantation, issues can arise with endogenous mitochondrial DNA (mtDNA) contributing to organ damage.
  • Researchers found that mtDNA is higher in lung transplant cases with primary graft dysfunction (PGD) and triggers inflammation through TLR9 receptors, leading to harmful neutrophil extracellular trap (NET) formation.
  • Therapy targeting DNaseI could offer a dual benefit in PGD by neutralizing the triggering mtDNA and breaking down the damaging NETs, ultimately helping to reduce lung injury.
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Despite current immunosuppressive strategies, long-term lung transplant outcomes remain poor due to rapid allogenic responses. Using a stringent mouse model of allo-airway transplantation, we identify the CCR4-ligand axis as a central node driving secondary lymphoid tissue homing and activation of the allogeneic T cells that prevent long-term allograft survival. CCR4 deficiency on transplant recipient T cells diminishes allograft injury and when combined with CTLA4-Ig leads to an unprecedented long-term lung allograft accommodation.

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Background: The long term clinical significance of respiratory infections after lung transplantation remains uncertain.

Methods: In this retrospective single-center cohort study of 441 lung transplant recipients, we formally evaluate the association between respiratory infection and chronic lung allograft dysfunction (CLAD). We furthermore hypothesized that bronchoalveolar lavage fluid (BALF) CXCL9 concentrations are augmented during respiratory infections, and that episodes of infection with elevated BALF CXCL9 are associated with greater CLAD risk.

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Background: Aspergillus colonization after lung transplant is associated with an increased risk of chronic lung allograft dysfunction (CLAD). We hypothesized that gene expression during Aspergillus colonization could provide clues to CLAD pathogenesis.

Methods: We examined transcriptional profiles in 3- or 6-month surveillance bronchoalveolar lavage fluid cell pellets from recipients with Aspergillus fumigatus colonization (n = 12) and without colonization (n = 10).

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Rationale: Since the pathogenesis of chronic lung allograft dysfunction (CLAD) remains poorly defined with no known effective therapies, the identification and study of key events which increase CLAD risk is a critical step towards improving outcomes. We hypothesized that bronchoalveolar lavage fluid (BALF) CXCR3 ligand concentrations would be augmented during organizing pneumonia (OP) and that episodes of OP with marked chemokine elevations would be associated with significantly higher CLAD risk.

Methods: All transbronchial biopsies (TBBX) from patients who received lung transplantation between 2000 to 2010 were reviewed.

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Platelets are critical for haemostasis, thrombosis, and inflammatory responses, but the events that lead to mature platelet production remain incompletely understood. The bone marrow has been proposed to be a major site of platelet production, although there is indirect evidence that the lungs might also contribute to platelet biogenesis. Here, by directly imaging the lung microcirculation in mice, we show that a large number of megakaryocytes circulate through the lungs, where they dynamically release platelets.

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Background: Chronic Lung Allograft Dysfunction (CLAD) is the main limitation to long-term survival after lung transplantation. Although CLAD is usually not responsive to treatment, earlier identification may improve treatment prospects.

Methods: In a nested case control study, 1-year post transplant surveillance bronchoalveolar lavage (BAL) fluid samples were obtained from incipient CLAD (n = 9) and CLAD free (n = 8) lung transplant recipients.

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Article Synopsis
  • Lung transplant recipients (LTR) have a high risk of developing cutaneous squamous cell carcinoma (SCC), and recent findings indicate that voriconazole, an antifungal medication, may be linked to this risk.
  • A study conducted at UCLA evaluated 400 adult LTRs, comparing two groups: one that received targeted antifungal prophylaxis and another that received universal prophylaxis after a protocol change in 2009.
  • The results showed that the universal prophylaxis cohort had a significantly higher risk of SCC, and greater cumulative exposure to voriconazole was associated with this increased risk, suggesting caution in using voriconazole for these patients.
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Survival in patients with cystic fibrosis (CF) has improved dramatically over the past 30 to 40 years, with mean survival now approximately 40 years. Nonetheless, progressive respiratory insufficiency remains the major cause of mortality in CF patients, and lung transplantation (LT) is eventually required. Timing of listing for LT is critical, because up to 25 to 41% of CF patients have died while awaiting LT.

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Rationale: Primary graft dysfunction (PGD) causes early mortality after lung transplantation and may contribute to late graft failure. No effective treatments exist. The pathogenesis of PGD is unclear, although both neutrophils and activated platelets have been implicated.

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Primary graft dysfunction (PGD), as characterized by pulmonary infiltrates and high oxygen requirements shortly after reperfusion, is the major cause of early morbidity and mortality after lung transplantation. Donor, recipient and allograft-handling factors are thought to contribute, although new insights regarding pathogenesis are needed to guide approaches to prevention and therapy. Mast cells have been implicated in ischemic tissue injury in other model systems and in allograft rejection, leading to the hypothesis that mast cell degranulation contributes to lung injury following reperfusion injury.

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Rationale: After lung transplantation, insults to the allograft generally result in one of four histopathologic patterns of injury: (1) acute rejection, (2) lymphocytic bronchiolitis, (3) organizing pneumonia, and (4) diffuse alveolar damage (DAD). We hypothesized that DAD, the most severe form of acute lung injury, would lead to the highest risk of chronic lung allograft dysfunction (CLAD) and that a type I immune response would mediate this process.

Objectives: Determine whether DAD is associated with CLAD and explore the potential role of CXCR3/ligand biology.

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Background: Community acquired respiratory virus (CARV) infections in lung transplant recipients (LTR) have been associated with adverse outcomes, including acute rejection (AR) and decline in allograft function, in some but not in all studies.

Methods: Spirometry and transbronchial biopsy results of LTR diagnosed with CARV infection over a two-yr period were extracted from clinical records. Primary outcomes, studied at 1-2.

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Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-related mortality. TRALI presents as acute lung injury (ALI) within 6 hours after blood product transfusion. Diagnosing TRALI requires a high index of suspicion, and the exclusion of circulatory overload or other causes of ALI.

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