Serum and urinary NGAL but not KIM-1 raises in human postrenal AKI.
BACKGROUND
We examined the value of the novel acute kidney injury (AKI) markers neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) in acute postrenal impairment. These biomarkers have been evaluated in prerenal and intrarenal AKI so far, but not in human acute postrenal kidney injury. With regard to multimorbid and critically ill patients the discrimination of different AKI origins often remains a challenge. As the trend goes towards a diagnostic panel of AKI markers, we hereby aim to contribute to evaluate further options of discrimination in an observational case-control study.


METHODS
Blood and urine samples were obtained from 53 patients with acute obstructive nephropathy secondary to ureteral calculi and 52 age-matched healthy controls. Serum NGAL (sNGAL), urinary NGAL (uNGAL) and urinary KIM-1 (uKIM-1) levels were determined using a commercially available ELISA kit, creatinine applying the Jaffé's method.


RESULTS
While urinary levels of KIM-1 were not significantly different between patients with obstructive nephropathy and controls, a striking increase in sNGAL (P < 0·001) and uNGAL (P < 0·01) levels was detected in the obstructive nephropathy group. Within the obstructive nephropathy group, sNGAL (P = 0·01) and uNGAL (P = 0·049) but not uKIM-1 correlated positively with the white blood cell count and uNGAL correlated positively (P = 0·002) with the extent of leucocyturia.


CONCLUSIONS
High levels of sNGAL and uNGAL observed in stone-induced acute obstructive nephropathy may represent a valuable marker of postrenal AKI. Low uKIM-1 levels may help to discriminate postrenal AKI events using a panel of markers in this setting.
Faculty of Medicine, Philipps-University Marburg, Marburg, Germany.
Anja
A
Urbschat
Stefan
S
Gauer
Patrick
P
Paulus
Manuel
M
Reissig
Christine
C
Weipert
Elizabeth
E
Ramos-Lopez
Rainer
R
Hofmann
Peyman
P
Hadji
Helmut
H
Geiger
Nicholas
N
Obermüller
D058186:Acute Kidney Injury / Q000175:diagnosis* / Q000209:etiology; D000209:Acute-Phase Proteins / Q000378:metabolism*; D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D016022:Case-Control Studies; D005260:Female; D000072596:Hepatitis A Virus Cellular Receptor 1; D006801:Humans; D000071068:Lipocalin-2; D054834:Lipocalins / Q000378:metabolism*; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D011991:Receptors, Virus / Q000378:metabolism*; D056844:Renal Colic / Q000209:etiology; D014514:Ureteral Calculi / Q000150:complications; D014517:Ureteral Obstruction / Q000209:etiology
D000209:Acute-Phase Proteins; D015415:Biomarkers; C491143:HAVCR1 protein, human; D000072596:Hepatitis A Virus Cellular Receptor 1; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D008562:Membrane Glycoproteins; D011518:Proto-Oncogene Proteins; D011991:Receptors, Virus
Acute kidney injury; KIM-1; NGAL; biomarker; postrenal obstruction; renal colic