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Background Radioiodine is efficiently concentrated by tissues expressing the human sodium iodide symporter (hNIS). The aim of this study was to analyze the effects of 131I on acute cardiac allograft rejection after hNIS ex-vivo gene transfer in a rat model of cardiac allotransplantation.

BACKGROUND: In this investigation we studied the efficacy and durability of recombinant adeno-associated virus serotype 9 (rAAV9) vector-mediated gene transfer to the transplanted rat heart. METHODS: A rAAV9-CMV-lacZ vector diluted in cold (4 degrees C) University of Wisconsin solution was used to perfuse the rat coronary vasculature for 20 minutes prior to syngeneic heterotopic transplantation. Perfusion experiments (six groups, n = 3/group) were performed without rAAV9 and at four separate doses ranging from 2 x 10(9) to 2 x 10(12) viral genomes/ml. The transplanted heart was recovered 10 days or 3 months after transplantation and expression of lacZ assessed by histology, enzyme-linked immunoassay and real-time reverse transcript-polymerase chain reaction (RT-PCR). In a final group (n = 3), rAAV9 was administered systemically to compare the cardiac transduction efficiency and viral distribution to other organs. RESULTS: Transduction efficiency of perfused virus correlated with vector dose (p < 0.0001), with myocardial transduction ranging up to 71.74% at the highest dose. Cardiac expression of lacZ was equivalent at 10 days and 3 months. There was no evidence of viral gene transfer to other organs after heart transplantation. CONCLUSIONS: Our findings demonstrate efficient and durable rAAV9-mediated gene transfer to the transplanted heart after ex vivo perfusion and suggest that AAV9 is a promising vector for cardiac gene therapy.

Objective: We studied the concordance of transgene expression in the transplanted heart using bicistronic adenoviral vector coding for a transgene of interest (human carcinoembryonic antigen: hCEA — beta human chorionic gonadotropin: bhCG) and for a marker imaging transgene (human sodium iodide symporter: hNIS). Methods: Inbred Lewis rats were used for syngeneic heterotopic cardiac transplantation. Donor rat hearts were perfused ex vivo for 30 min prior to transplantation with University of Wisconsin (UW) solution (n = 3), with 10 9 pfu/ml of adenovirus expressing hNIS (Ad-NIS;n = 6), hNIS-hCEA (Ad-NIS-CEA; n = 6) and hNIS-bhCG (Ad-NIS-CG; n = 6). On postoperative day (POD) 5, 10, 15 all animals underwent micro-single photon emission computed tomography/computed tomography (SPECT/CT) imaging of the donor hearts after tail vein injectionof 1000 mCi 123 I and bloodsamplecollection forhCEA and bhCG quantification.Results:Significantlyhigherimageintensity wasnoted in the hearts perfused with Ad-NIS (1.1 0.2; 0.9 0.07), Ad-NIS-CEA (1.2 0.3; 0.9 0.1) and Ad-NIS-CG (1.1 0.1; 0.9 0.1) compared to UW group (0.44 0.03; 0.47 0.06) on POD 5 and 10 (p < 0.05). Serum levels of hCEA and bhCG increased in animals showing high cardiac 123 I uptake, but not in those with lower uptake. Above this threshold, image intensities correlated well with serum levels of hCEA and bhCG (R 2 = 0.99 and R 2 = 0.96, respectively). Conclusions: These data demonstrate that hNIS is an excellent reporter gene for the transplanted heart. The expression level of hNIS can be accurately and non-invasively monitored by serial radioisotopic SPECT imaging. High concordance has been demonstrated between imaging and soluble marker peptides at the maximum transgene expression on POD 5. # 2007 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.

Background Adenovirus serotype 5 has remained the pre-eminent vector in pre-clinical gene therapy applications in cardiac transplantation. Concerns over the potential effects of adenoviral vectors on the later development of cardiac allograft vasculopathy (CAV) are addressed in this study. Methods Hearts ( n = 22) harvested from Brown Norway rats were perfused ex vivo with either University of Wisconsin (UW) solution with no virus, Ad-CMV-LacZ or Ad-CMV-Null. Donor hearts were transplanted heterotopically into the abdomen of Lewis rats. All recipients received cyclosporine for the duration of the experiment. Transplanted hearts were recovered for analysis at 120 days. Sections of the heart were stained with elastic–van Gieson stain for morphometric analysis of the vessels to ascertain the degree of vascular luminal occlusion. Hematoxylin–eosin staining facilitated diagnosis of chronic rejection. Results Seventy-seven percent of transplanted hearts showed signs of chronic rejection with no difference in the proportion of animals between groups ( p = 0.797). No difference was noted in the degree of vascular luminal occlusion between the Ad-Null (0.57 ± 0.22), Ad-LacZ (0.62 ± 0.19) and UW (0.47 ± 0.29) groups ( p = 0.653). Conclusions Vascularized cardiac allografts transplanted from Brown Norway to Lewis rats demonstrated cardiac allograft vasculopathy CAV at 120 days. Adenoviral perfusion of the donor heart ex vivo did not affect the development of CAV.

A 43-year-old male was transferred to our institute. His heart rhythm on admission was ventricular fibrillation (VF) which was successfully defibrillated with a direct current shock (DC). A diagnosis of short QT syndrome (SQTS) was made on the basis of an abnormally short QT interval of 280 ms during the sinus rhythm. During treatment for mild total hypothermia, VF recurred repeatedly necessitating DCs. Nifekalant at a dose of 0.3 mg/kg was intravenously administered, the QT interval was prolonged from 280 to 370 ms and VF no longer recurred. Subsequently the patient underwent implantation of an implantable cardioverter defibrillator.