Mycophenolate mofetil versus azathioprine therapy is associated with a significant protection against long-term renal allograft function deterioration.
BACKGROUND
To evaluate the association of long-term continuous mycophenolate mofetil (MMF) versus azathioprine (AZA) therapy and renal allograft function, as measured by the slope of reciprocal creatinine, we analyzed 49,666 primary renal allograft recipients reported to the United States Renal Data System between October 31, 1988 and June 30, 1998.


METHODS
The primary study endpoint was defined as a greater than 20% decrease below a 6-month baseline of 1/serum creatinine (SCr) (slope of reciprocal creatinine) at or beyond 1 year after transplantation. A secondary endpoint was defined as reaching an SCr value greater than 1.6 mg/dL. Univariate Kaplan-Meier analysis and multivariate Cox proportional hazard models were used to investigate the risk of reaching the study endpoints. Multivariate analyses were corrected for potential confounding covariates.


RESULTS
According to the Cox proportional hazard model, 12-month continued therapy of MMF versus AZA was associated with a protective effect against declining renal function, as measured by the slope of reciprocal creatinine (relative risk [RR]=0.84, confidence interval 0.78-0.91, P<0.001). For 24-month continued therapy of MMF versus AZA, MMF was associated with a further decreased risk for a decline in renal function (RR=0.66, confidence interval=0.57-0.77, P<0.001). Furthermore, MMF was associated with a protective effect against reaching the SCr threshold of 1.6 mg/dL (RR=0.80, P<0.001) beyond 12 months posttransplantation.


CONCLUSIONS
Continuous use of MMF versus AZA was associated with a protective effect against declining renal function beyond 1 year after transplantation. Further study is needed to confirm that continued MMF therapy is protective against long-term deterioration in renal function.
Meier-Kriesche
Herwig-Ulf
HU
Department of Internal Medicine, University of Florida College of Medicine, Gainesville, FL 32610-0224, USA. meierhu@medicine.ufl.edu.
Steffen
Bettina J
BJ
Hochberg
Alan M
AM
Gordon
Robert D
RD
Liebman
Michael N
MN
Morris
Jonathan A
JA
Kaplan
Bruce
B
D000328:Adult; D001379:Azathioprine / Q000627:therapeutic use*; D003404:Creatinine / Q000097:blood; D005260:Female; D006085:Graft Survival / Q000187:drug effects; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D007668:Kidney / Q000187:drug effects / Q000503:physiopathology; D007674:Kidney Diseases / Q000517:prevention & control*; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D009173:Mycophenolic Acid / Q000031:analogs & derivatives / Q000627:therapeutic use*; D016016:Proportional Hazards Models; D016019:Survival Analysis; D014184:Transplantation, Homologous
D007166:Immunosuppressive Agents; D003404:Creatinine; D009173:Mycophenolic Acid; D001379:Azathioprine