Correlation between cystatin C and serum creatinine as markers of renal function in patients with neoplasms of the locomotor system.

Creatinine levels and clearance are used to monitor renal function in clinical practice. Cystatin C is produced by most nucleated cells in a consistent manner, uninfluenced by inflammatory processes, sex, age, eating habits or nutritional status. Serum cystatin C concentrations are mainly dependent on glomerular activity and are an endogenous biochemical marker of glomerular filtration. The aim of this study was to test the efficiency of cystatin C assay as an alternative marker of renal function. Statistical analysis of our results showed that cystatin C levels were significantly correlated to creatinine and creatinine clearance levels. However, it is still premature to suppose that cystatin C can replace creatinine in routine tests. Establishing cystatin C levels can be useful in cases in which it is not possible to determine creatinine clearance.