Assessment of renal function using cystatin C and creatinine in Saudi patients after transplantation

Background: Rapid and accurate assessment of kidney function in patients after transplantation is of utmost importance. The aim of this study was to compare the relationships of serum creatinine and serum cystatin C with an estimated glomerular filtration rate (eGFR) in kidney transplants Saudi patients after a certain period of transplantation. Materials and Methods: In this prospective study, 127 patients were categorized into three groups based on their length of survival after kidney transplantation; <1 year, from 1 to 5 years, and above 5 years after transplantation. Results of cystatin C and creatinine levels were compared by eGFR derived from estimation equation chronic kidney disease epidemiology collaboration. Results: In the three assessed periods, the mean (standard deviation) cystatin C level was 1.72 (0.57), 1.59 (0.64), and 1.82 (0.82), respectively, being highest after 5 years of transplantation, normal in 9.40%, and elevated in 90.60% of the participants, while creatinine level, decreased from 1.57 (0.53) to 1.52 (0.64) in 1-5 years, then it became the highest at 1.75 (0.69) in more than 5 years. The mean was normal in 21.30% and elevated in 78.70% of the patients. Both serum creatinine and cystatin C levels were negatively correlated with posttransplantation time in kidney transplant patients. Conclusion: The cystatin C level was statistically significantly higher after 5 years of transplantation. It is a better parameter to rule out renal dysfunction after transplantation.