Potential biomarkers for the early detection of acute kidney injury after percutaneous nephrolithotripsy

Figures & data

Table 1. Comparison between PNL and control groups.

	PNL (n = 29)	Control (n = 47)
Age	37.3 ± 19.5	40.5 ± 21.4
Gender (M/F)	17/12	25/12
Laterality (L/R)	15/14
Stone size (mm^2)	95.8 ± 174.7

Notes: PNL, percutaneous nephrolithotomy; M, male; F, female; L, left; R, right.

Table 2. Early renal injury markers in patient with urolithiasis who underwent percutaneous nephrolithotripsy (PNL).

	Controls (n = 47)	Pre-op (n = 29)	Post-op 2h (n = 29)	Post-op 24h (n = 29)
NAG/Cr	0.07 ± 0.02	0.08 ± 0.028	0.16 ± 0.11	0.22 ± 0.11
KIM-1/Cr	1.46 ± 0.86	2.12 ± 0.98	3.32 ± 1.78	4.47 ± 2.41
NGAL/Cr	374 ± 115	475 ± 173	804 ± 215	1034 ± 662
LFABP/Cr	0.22 ± 0.08	0.37 ± 0.14	0.55 ± 0.24	0.68 ± 0.36

Table 3. Differences (p values) in the early kidney injury markers/creatinine ratios between the first measurements and the control groups.

Compared modalities	KIM-1/Cr	NGAL/Cr	LFABP/Cr	NAG/Cr
Preop/Postop 2 h	NS	NS	NS	NS
Preop/Postop 24 h	0.001	0.013	NS	0.001
Postop 2h/Postop 24 h	0.045	NS	NS	0.002
Preop/Controls	NS	NS	NS	NS

Note: NS, not significant (p > 0.05).

Figure 1. Urinary biomarkers measured in the control and patient group with preoperative and postoperative values.

Table 4. Basic characteristics of some urinary biomarkers.

Biomarker	Comments
Kidney injury molecule-1	Type-1 cell membrane glycoprotein upregulated in dedifferentiated proximal tubule epithelial cells. Protein ectodomain found to be shed in urine following acute injury.
Neutrophil gelatinase-associated lipocalin	Initially identified, bound to gelatinase in specific granules of the neutrophil, but also may be induced in epithelial cells in the setting of inflammation or malignancy. Expression upregulated in proximal tubule cells following the ischemic renal injury.
Liver-type fatty acid binding protein	Expressed in proximal tubule epithelial cells. Important functions include intracellular fatty acid transport and possible sequestration of reactive fatty acid oxidation products.
N-acetyl-d-glucosaminidase	Proximal tubule lysosomal enzyme. More stable than other urinary enzymes.