Urine Albumin Creatinine Ratio May Predict Graft Function After Kidney Transplant

The albumin to creatinine ratio (ACR) has been shown to be an important prognostic marker in kidney disease. The ACR has been shown to predict graft failure and patient death after kidney transplant.

From March 1, 2011, to December 31, 2013, we checked the urine ACR and blood for highly sensitive C-reactive protein in 93 kidney recipients who regularly follow up at out institute. We tested the linear correlations of these parameters with estimated glomerular filtration rate. Furthermore, we used multivariate linear regression to examine its value in predicting graft function. Finally, we used receiver operating characteristic curve analysis to validate their predictive value on creatinine clearance > 45 mL/min.

With multivariate linear regression, the latest estimated glomerular filtration rate has a strong linear relationship with initial ACR (B = -0.032; P = .02), suggesting each unit rise in ACR with a decrease in creatinine clearance by 0.032 mL/min. To investigate their value in predicting good functional graft defined as creatinine clearance >45 mL/min, a receiver operating characteristic curve analysis was applied on these parameters. The area under curve for age is 0.496, for body weight is 0.539, and for highly sensitive C-reactive protein is 0.582, which are all around the chance of 0.5 by flipping coins. The area under ACR curve is 0.825, better than above parameters, and only second to serum creatinine level.

Urine ACR is a simple and effective measure to predict graft function after a kidney transplant. It has similar independent strong correlations to creatinine clearance comparing with serum creatinine without requirement of a blood draw.