Effects of mycophenolate mofetil on cardiac allograft survival and cardiac allograft vasculopathy in miniature swine.
BACKGROUND
Chronic rejection, as manifested by cardiac allograft vasculopathy, remains the leading cause of late graft failure in heart transplant recipients. Despite recent clinical trials, the efficacy of mycophenolate mofetil in preventing human cardiac allograft vasculopathy remains controversial. We investigated whether mycophenolate mofetil would prevent cardiac allograft vasculopathy and prolong cardiac allograft survival in our well-established miniature swine model of heart transplantation.


METHODS
Hearts disparate at the major histocompatibility complex class I locus were heterotopically transplanted into miniature swine recipients treated with a 12-day course of mycophenolate mofetil (n = 3) or cyclosporine A (n = 3). Allograft survival, acute rejection, and chronic rejection were monitored in the two groups.


RESULTS
Hearts transplanted with 12 days of cyclosporine were rejected between 46 and 61 days, whereas two of the three hearts transplanted with mycophenolate mofetil remained beating beyond 120 days (p = 0.02). At necropsy, there was a 4.9% mean prevalence of cardiac allograft vasculopathy in the mycophenolate mofetil group as compared with 16.6% in the cyclosporine group (p = 0.03). Cardiac allograft rejection and vasculopathy in the cyclosporine-treated group was associated with prominent myocardial interferon-gamma gene expression, a finding absent in two thirds of the mycophenolate mofetil-treated swine. Moreover, the mycophenolate mofetil-treated swine failed to develop IgM or IgG alloantibodies.


CONCLUSIONS
A short course of mycophenolate mofetil resulted in a longer allograft survival than a similar course of cyclosporine. Moreover, mycophenolate mofetil reduced the prevalence of cardiac allograft vasculopathy as compared with cyclosporine-treated controls. The salutary effect of mycophenolate mofetil may be related to its ability to decrease interferon-gamma expression in the myocardium and prevent the generation of alloantibodies.
Schwarze
Margaret L
ML
Transplantation Biology Research Center, Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA.
Houser
Stuart L
SL
Muniappan
Ashok
A
Allan
James S
JS
Menard
Matthew T
MT
McMorrow
Isabel
I
Maloney
Michaella E
ME
Madsen
Joren C
JC
D000818:Animals; D006085:Graft Survival / Q000187:drug effects*; D016027:Heart Transplantation; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D009173:Mycophenolic Acid / Q000031:analogs & derivatives* / Q000627:therapeutic use; D013552:Swine; D013556:Swine, Miniature
D007166:Immunosuppressive Agents; D009173:Mycophenolic Acid