Risk factors for rising creatinine in renal allografts with 1 and 3 yr survival

Background: Determining factors associated with negative slope of inverse creatinine vs. time (1/Cr vs. t) may help prevent a decline in renal allograft function. Methods: A total of 1389 adult recipients of primary renal transplants were divided into quartiles based on the slope of 1/Cr vs. t calculated from 6 and 12 months post transplant. A multivariate analysis of risk factors for being in the worst vs. best quartile employed these variables: donor source, HLA mismatch, recipient age, donor age, panel-reactive antibody (PRA), acute rejection (AR), 3-month cyclosporin A (CsA) level, 1-yr CsA level and acute tubular necrosis. Two separate analyses compared risk factors in patients with 1 and 3 yr survival, respectively. Results: In recipients with ≥1 yr graft survival, highPRA and AR were associated with negative slopes of 1/Cr vs. t. For those with ≥3 yr graft survival, both AR and 3-month CsA level >150 ng/mL were significant risk factors, using both 6- and 12-month slopes. Stratification of AR showed 1 AR episode ≥6 months and multiple AR episodes carried significant risk for negative slopes. Conclusion: Optimization of allograft function invokes a conundrum between the needs to avoid both AR and high early CsA levels. We support a policy of carefully balancing these two risks.