Effect of hemodialysis on circulating cystatin c levels in patients with end stage renal disease.

Plasma cystatin C is an emerging parameter to assess kidney function. Its utility in assessing the adequacy of hemodialysis in patients with end-stage-renal disease has however not been established with certainty. This study was therefore carried out to assess the usefulness of serum cystatin C estimation in patients undergoing low flux membrane hemodialysis. Serum creatinine and cystatin C were estimated in 20 patients before and after undergoing hemodialysis. The mean serum creatinine decreased from a pre-dialysis value of 7.72 mg/dL to a post-dialysis value of 2.90 mg/dL. On the contrary, the mean serum cystatin C levels were found to increase from a pre-dialysis value of 5.97 mg/L to a post-dialysis value of 8.25 mg/L. Therefore, serum cystatin C cannot be used to monitor dialysis adequacy. It however, serves as a surrogate marker of the inadequacy of low flux membrane bicarbonate hemodialysis in clearing low molecular weight proteins from the circulation.