Improved assessment of graft function by echocardiography in cynomolgus monkey recipients of hDAF-transgenic pig cardiac xenografts.
BACKGROUND
The current practice of evaluating heterotopic heart xenografts by palpation allows only detection of severe graft dysfunction, which indicates terminal graft failure. Therefore, we evaluated whether echocardiography is a better method of detecting early graft dysfunction as a marker of rejection in abdominal pig heart xenografts in cynomolgus monkeys.


METHODS
Six cynomolgus monkeys received heterotopic heart transplants from pig donors transgenic for human decay-accelerating factor (hDAF). Induction therapy consisted of either cyclophosphamide or rabbit anti-thymocyte globulin. Maintenance therapy consisted of cyclosporine or tacrolimus, steroids, and sodium mycophenolate or mycophenolate mofetil, GAS914 (alphaGal oligosaccharide containing glycoconjugate), and for some animals TP10 (soluble complement receptor type 1). Echocardiography was performed immediately after transplantation and 3 times a week after surgery. We scored contractility and measured left ventricular wall thickness. Impaired contractility or increased wall thickness were considered graft dysfunction and were treated with pulse steroids. Palpation score was recorded daily. We also obtained myocardial biopsy specimens.


RESULTS
Palpation score remained at 4 out of 4 in all animals until 2 to 5 days before final graft failure, whereas echocardiography detected several episodes of impaired graft function, either decreased left ventricular contractility or increased left ventricular wall thickness before graft failure. Treatment with pulse steroids improved graft function only during early episodes of graft impairment. Final graft failure was steroid resistant and caused by severe vascular rejection.


CONCLUSIONS
Echocardiography is a better method of assessing graft dysfunction than is palpation. Therefore, echocardiography may detect early rejection episodes of heterotopic heart xenografts in non-human primates.
Stalder
Mario
M
Transplantation Immunology, Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, CA, USA.
Tye
Terry
T
Lam
Tuan T
TT
Chan
Michael C Y
MC
Berry
Gerald J
GJ
Borie
Dominic C
DC
Morris
Randall E
RE
D000818:Animals; D030801:Animals, Genetically Modified; D001706:Biopsy; D018958:CD55 Antigens / Q000235:genetics; D004452:Echocardiography / Q000662:veterinary; D005819:Genetic Markers; D006084:Graft Rejection / Q000000981:diagnostic imaging*; D016027:Heart Transplantation; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology; D008252:Macaca fascicularis; D008297:Male; D023421:Models, Animal; D008955:Models, Cardiovascular; D009200:Myocardial Contraction; D009206:Myocardium / Q000473:pathology; D010173:Palpation; D013223:Statistics as Topic; D013552:Swine / Q000235:genetics; D014183:Transplantation, Heterologous
D018958:CD55 Antigens; D005819:Genetic Markers