Changes in Plasma Cystatin C after Renal Transplantation and Acute Rejection in Adults

Abstract

Abstract Background: Cystatin C has recently been proposed as an alternative marker of glomerular filtration rate. The diagnostic value of plasma cystatin C for the longitudinal assessment of kidney function after renal transplantation, however, has not been addressed. Methods: Renal function was evaluated in 30 adults receiving renal transplants (46 ± 9 years, mean ± SD) and in 56 healthy controls (38 ± 10 years) using cystatin C. Plasma cystatin C was determined daily starting the day of surgery and for 3 weeks after surgery by an immunonephelometric assay. Results: Plasma concentration significantly decreased during the first week (−44% vs −29% for creatinine). Plasma cystatin C correlated with plasma creatinine (r = 0.741; P <0.0001) and the reciprocal of the creatinine clearance estimated by the Cockcroft-Gault formula (r = 0.882; P <0.001). In all three cases of acute renal impairment, the increase in plasma cystatin C values was more prominent than that of creatinine. Conclusions: Plasma cystatin C is an alternative and accurate marker of allograft function in adult transplant patients. Increased sensitivity compared with creatinine for the detection of acute reduction in glomerular filtration rate allows in some cases a more rapid diagnosis of acute rejection or treatment nephrotoxicity.