Early term effect of ureterorenoscopy (URS) on the Kidney: research measuring NGAL, KIM-1, FABP and CYS C levels in urine

ABSTRACT Aim: URS is a very commonly used procedure for treatment of ureter stones. Increased hydrostatic pressure in the collecting system linked to fluids used during the procedure may cause harmful effects on the kidney. The aim of this study is to determine whether the URS procedure has a negative effect on the kidney by investigating NGAL, KIM-1, FABP and Cys C levels in urine. Material and Methods: This study included 30 patients undergoing ureterorenoscopy (URS) for ureter stones. Urine samples were collected 5 times; before the URS procedure (control) and at 1, 3, 5 and 12 hours following the procedure. NGAL, KIM-1, FBAP and Cys C levels were measured in urine and compared with the control values. Results: The NGAL levels in urine before the procedure and at 1, 3, 5 and 12 hours after the procedure were 34.59±35.34; 62.72±142.32; 47.15±104.48; 45.23±163.16 and 44.99±60.79ng/mL, respectively (p=0.001). Similarly, the urinary KIM-1, FABP and Cys C levels were found to increase compared to control values; however this increase did not reach statistical significance (p >0.05). Conclusions: After the URS procedure, there were important changes in NGAL, FABP, KIM-1 and Cys C levels. These changes reached statistical significance for NGAL, but did not reach significance for the other parameters. In conclusion, the URS procedure significantly affects the kidney; however, this effect disappears over time.

Assessment of the Accuracy and Precision of Cystatin C-based GFR Estimates and Cr-based GFR Estimates in Comparison with Cr51-EDTA GFR / 대한진단검사의학회지

BACKGROUND: Cystatin C (cysC) is said to be an ideal marker for glomerular filtration rate (GFR), independent of external factors such as age, nutrition and inflammation. The authors compared the accuracy and precision of cysC-based and creatinine (Cr)-based GFR estimates using Cr51-EDTA GFR method as a reference. METHODS: Serum concentrations of cysC and Cr were measured in adults over 17 yr (n=170) and children below 17 yr (n=79) who had had GFR estimated by Cr51-EDTA method. CysC-based GFR was estimated by the formula of Thierry [CysC-based GFR estimates (mL/min/1.73 m2)=78 x (1/cysC, in mg/L)+4] and Cr-based GFR by the formula of modified Modification of Diet in Renal Disease [MDRD II, Cr-based GFR estimates (mL/min/1.73 m2)=186 x (Scr)(-1.154) x (Age)(-0.203) x 0.742 (for a female patient) x 1.212 (for a black patient). RESULTS: In comparison with Cr51-EDTA GFR, in children below 17 yr, the bias +/- standard deviation (SD) of cysC-based and Cr-based GFR estimates were 7.5 +/- 6.1 and 106.5 +/- 98.2, respectively, in the range of below 90 of Cr51-EDTA GFR (mL/min/1.73 m2), and 33.7 +/- 33.0 and 174.4 +/- 18.8 in the range of over 90. In adults over 17 yr, the respective figures were 13.1 +/- 11.0 and 17.4 +/- 29.8 in below 90, and 21.2 +/- 20.1 and 83.6 +/- 108.8 in over 90 of Cr51-EDTA GFR. CONCLUSIONS: CysC-based GFR estimates show acceptable ranges of biases over the whole age and GFR ranges. CysC-based GFR estimates is considered to be the marker for GFR, which could be used without limitation of age and GFR ranges.