Specific gene expression profile associated with ischemia-reperfusion injury during lung transplantation identified by CDNA microarray

The Journal of Heart and Lung Transplantation Volume 22, Number 1S Previous studies in heart-lung transplant recipients have shown that air trapping on thin-section expiratory computerized tomography (CT) examination is sensitive, specific, and accurate for the diagnosis of bronchiolitis obliterans syndrome (BOS). Accurate interpretation of sequential examinations, however, requires knowledge about the regional variability of air trapping. The aim of this study was therefore to quantify the intra-patient reproducibillity of the extent and anatomical distribution of air trapping. Nineteen heart-lung transplant recipients (8 with and 11 without BOS) underwent three expiratory CT examinations within 60 minutes. Residual volumes were measured on CT. Anatomical distribution and extent of air trapping were scored, and respective reproducibilities were calculated. CT examinations were compared using an analysis of variance that took into account interobserver and BOS/non-BOS effects. The Spearman rank correlation coefficient (rs) was calculated to test the association between variability of residual volumes and variability of extent of air trapping. Residual volumes did not significantly differ between the three CT examinations (P ⫽ 0.556). Reproducibilities of the anatomical distribution of air trapping ranged from 84.2% to 94.7%, with a tendency to better reproducibility in patients without BOS. Reproducibilities of the extent of air trapping ranged from 97.1% to 97.7%. The rs coefficients ranged from 0.382 to 0.568 (P ⫽ 0.105 to 0.016). No interobserver effect was detected (P ⫽ 0.994). This study thus shows that anatomical distribution and extent are reproducible characteristics of air trapping. No substantial variability of air trapping occurs in functionally stable heart-lung transplant recipients with and without BOS. This should increase the diagnostic confidence in air trapping seen in these patients. 348 SPECIFIC GENE EXPRESSION PROFILE ASSOCIATED WITH ISCHEMIA-REPERFUSION INJURY DURING LUNG TRANSPLANTATION IDENTIFIED BY CDNA MICROARRAY M. Yamane, S.M. Quadri, L. Segall, A. Dutly, T.K. Waddell, M. Liu, S. Keshavjee, Thoracic Surgery Research Laboratory, Toronto General Research Institute, Toronto, ON, Canada Background: Ischemia-Reperfusion injury in lung transplantation (LTx) is a serious clinical problem can lead to significant morbidity and mortality in LTx recipients. We have previously demonstrated that the patterns of cell death during reperfusion shift from predominantly apoptosis to necrosis as the length of cold storage increases. As an initial step towards a better understanding of this process, we studied the profile of gene expression after preservation and LTx. Methods: Lewis rat lung grafts were stored for 6 or 24 hours followed by transplantation and reperfusion for 2 hours; 4 transplants / group. Total RNA was extracted from lung tissues and examined with microarray techniques using human OCI 1.7k cDNA chips to detect alterations in gene expression. Hierarchical clustering was carried out to profile the pattern of gene expression. Genes were considered upregulated if the expression was ⬎ 2 fold increased, and downregulated if ⬍0.5 fold, as compared to normal lungs. Results: Graft function after 2h of reperfusion was significantly different between 6h⫹Tx and 24h⫹Tx (PO2: 6h vs. 24h, 420.6 ⫾ 75.9 vs. 111.3 ⫾ 59.2, p ⫽ 0.0007). From microarray analysis, total 59 of 1,718 genes on the gene chip were found to be up-regulated after 6h⫹Tx (23 genes) and/or 24h⫹Tx (45 genes). Some genes appear to be related to reperfusion (increased after 6h⫹Tx and 24h⫹Tx, 9 genes of 59). Some genes were upregulated specifically after 6h⫹Tx (14 genes ), but not after 24h⫹Tx. There is also pattern of gene expression which is up-regulated after reperfusion in both groups, more so in 24h⫹Tx. Conclusions: We observed many significant differences in the pattern of gene expression between short and long-term preserved lungs. In time,

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as we determine the identity of the specific genes involved, these intriguing findings may provide important insights into graft dysfunction and the mechanisms of cellular injury in LTx. 349 PREVALENCE OF GASTRO-ESOPHAGEAL REFLUX DISEASE IN LUNG TRANSPLANT CANDIDATES F. D’Ovidio, T.K. Waddell, M. de Perrot, D. Hadjiliadis, L. Miller, L.G. Singer, A. Pierre, G. Darling, S. Keshavjee, Toronto Lung Transplant Program, University of Toronto, Toronto, ON, Canada Gastro-esophageal reflux disease with possible aspiration has recently been associated with development of bronchiolitis obliterans in lung transplant patients. It is not clear whether the onset of gastro-esophageal reflux disease is secondary to intraoperative vagus nerve injury, drug induced impaired gastric emptying or is a pre-transplant existing condition. We therefore sought to investigate the prevalence of gastroesophageal reflux disease in the lung transplant candidate population. Material and Method:-Thirty-two consecutive patients assessed for lung transplantation were also screened for gastro-esophageal reflux disease: 11 patients had emphysema; 11 had pulmonary fibrosis; 10 had other diagnoses. All patients underwent stationary esophageal manometry. Esophageal 24 hr pH-metry testing, using two probes placed at 5 and 15 cm above the lower esophageal sphincter, was completed in 30 patients. The DeMeester gastro-esophageal reflux grading score was adopted. Results:-Nineteen patients (59%) complained of gastro-esophageal reflux related symptoms. The lower esophageal sphincter was hypotonic in 65% (21/32) of patients. Esophageal dysmotility, either due to alteration of peristalsis or of wave amplitude, was present in 25% (8/32) of patients. Significantly altered esophageal pH values were recorded in 43% (13/30) of patients. The overall DeMeester score was above normal in 37% (11/30) of all patients: in 18% (2/11) of the emphysema patients; in 55% (5/9) of the pulmonary fibrosis patients; and in 40% (4/10) of the patients with other diagnoses. Conclusions:-Gastro-esophageal reflux disease is highly prevalent in the lung transplant candidate population. This finding supports the importance of further investigation into the role of gastro-esophageal reflux in the development of end-stage lung disease, and on bronchiolitis obliterans syndrome after lung transplantation. 350 COST ANALYSIS OF UNIVERSAL PROPHYLAXIS VERSUS PREEMPTIVE THERAPY FOR CYTOMEGALOVIRUS J.A. Crompton,3 K. Carroll,1,4 C.A. Sullivan,3 S. Parker,3 S.V. Karwande,2 J. Stringham,2 D.A. Bull,2 B.C. Cahill,1,3 1Department of Medicine, University of Utah; 2Cardiothoracic Surgery, University of Utah; 3Lung Transplant Program, University of Utah; 4ARUP, Salt Lake City, UT Background: Lung transplant recipients (LTR) typically suffer from more CMV infection (infxn) compared to other transplant groups. Ganciclovir (GAN) prophylaxis (GPX) has been widely used but may increase cost and contribute to the development of CMV drug resistance. Compared to GPX, preemptive therapy (PRE), based on serial laboratory monitoring, may decrease both CMV resistance and utilized resources. We compared costs incurred in two LTR groups receiving GPX or PRE. Methods: Between 6/15/01-6/15/02, all primary LTR underwent serial quantitative PCR (COBAS Amplicor, Roche Diagnostics) monitoring without antiviral prophylaxis in the first 3 mo post-LT. GAN was initiated with any new positive test result and/or clinical suspicion of