Conversion from cyclosporine A to mycophenolate mofetil protects recipient kidney and prevents intimal hyperplasia in rat aortic allografts.
BACKGROUND
Recent studies have demonstrated that complete conversion from cyclosporine A (CsA) to mycophenolate mofetil (MMF) prolongs graft survival in patients undergoing clinical organ transplantation. We investigated the effects of conversion from CsA to MMF on recipient kidneys and transplant arteriosclerosis in a rat aortic allograft model as a high responder combination.


METHODS
DA (MHC haplotype, RT1a) rat abdominal aortic grafts were orthotopically transplanted into Lewis (RT1l) rats. The recipients were divided into four oral treatment groups: (1) vehicle group, (2) CsA group (15 mg/kg/day), (3) CsA/MMF40 group (conversion from CsA 15 mg/kg/day to MMF 40 mg/kg/day on day 14), and (4) CsA/MMF20 group (conversion from CsA 15 mg/kg/day to MMF 20 mg/kg/day on day 14). On day 28 after transplantation, the rats were sacrificed and the hematoserological parameters were analyzed. The grafted aortas and recipient kidneys also were evaluated histologically and immunohistochemically.


RESULTS
The CsA group developed serological renal dysfunction, arteriolar hyalinosis, and apoptosis in the recipient kidneys, whereas the CsA/MMF40 and CsA/MMF20 groups did not. In the vehicle group, we observed remarkable intimal hyperplasia and marked inflammatory cell infiltration including macrophages and T cells. In the CsA group, intimal hyperplasia was evident without infiltration of macrophages or T cells. In the CsA/MMF40 and CsA/MMF20 groups, intimal hyperplasia was abrogated, while adventitial infiltration of and adhesion to the endothelium by macrophages and T cells occurred.


CONCLUSIONS
Conversion from CsA to MMF protected recipient kidneys and prevented transplant arteriosclerosis. However, insufficient immunosuppression by MMF might reactivate immune cells. This conversion therapy has preventive potential in transplant patients with CsA-associated nephrotoxicity and transplant arteriosclerosis.
Shimizu
Hisashi
H
Center for Molecular Medicine, Division of Organ Replacement Research, Jichi Medical School, Minamikawachi-machi, Tochigi 329-0498, Japan.
Takahashi
Masafumi
M
Takeda
Shin-ichi
S
Inoue
Seiichiro
S
Fujishiro
Jun
J
Hakamata
Yoji
Y
Kaneko
Takashi
T
Murakami
Takashi
T
Takeyoshi
Izumi
I
Morishita
Yasuo
Y
Kobayashi
Eiji
E
D000818:Animals; D001012:Aorta, Abdominal / Q000276:immunology / Q000473:pathology / Q000637:transplantation*; D017209:Apoptosis / Q000187:drug effects; D001161:Arteriosclerosis / Q000209:etiology / Q000517:prevention & control*; D016572:Cyclosporine / Q000494:pharmacology*; D006965:Hyperplasia / Q000209:etiology / Q000517:prevention & control; D007166:Immunosuppressive Agents / Q000008:administration & dosage / Q000494:pharmacology*; D007668:Kidney / Q000098:blood supply / Q000187:drug effects* / Q000473:pathology; D008264:Macrophages / Q000187:drug effects / Q000276:immunology; D008297:Male; D009173:Mycophenolic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D051381:Rats; D011917:Rats, Inbred Lew; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D014184:Transplantation, Homologous; D017539:Tunica Intima / Q000473:pathology*; D015431:Weight Loss / Q000187:drug effects
D007166:Immunosuppressive Agents; D016572:Cyclosporine; D009173:Mycophenolic Acid