Serum cystatin C performs similarly to traditional markers of kidney function in the evaluation of donor kidney function prior to and following unilateral nephrectomy.

UNLABELLED: Background and objectives. It is essential that candidates for kidney donation be carefully screened to ensure safety of donation and monitored following unilateral nephrectomy as previous experience has demonstrated loss of kidney function of up to 50% following donation. The low-molecular-weight protein cystatin C (cysC) has been introduced as an alternative to serum creatinine for estimation of glomerular filtration rate (GFR). In particular, serum cysC is sensitive to detect mild GFR reduction between 60 and 90 ml/min/1.73 m(2) that would make it a potentially effective screening and monitoring test in live kidney donors. Design, setting, participants and measurements. We examined the utility of cysC as compared to other traditional measures of kidney function, including serum creatinine and 24-h urine for creatinine clearance, in the evaluation of kidney function in 51 consecutive live kidney donors both prior to and following unilateral nephrectomy.
RESULTS: This is the largest experience reported in the living kidney donor population. We found that living kidney donors at our centre lost approximately 30-35% of kidney function following unilateral nephrectomy and this remained stable >1 year. Furthermore, we observed that cysC correlated well with all other markers of kidney function and detected acute changes in kidney function immediately post-nephrectomy.
CONCLUSIONS: Overall, however, cysC did not confer any advantage with respect to preoperative assessment of kidney function or for monitoring following live kidney donation as compared to more traditional measures.