Assays of urine levels of HNL/NGAL in patients undergoing cardiac surgery and the impact of antibody configuration on their clinical performances.
BACKGROUND
Acute kidney injury (AKI) is one of the most serious postoperative complications of cardiac surgery. The lack of early and powerful markers for AKI makes the morbidity and mortality still very high. HNL (Human neutrophil lipocalin)/NGAL (Neutrophil gelatinase-associated lipocalin) was recently shown as a novel biomarker for AKI after cardiac surgery.


METHODS
Serial urine samples from 59 patients undergoing cardiac surgery were analyzed by polyclonal antibody based radioimmunoassay (RIA), monoclonal-polyclonal antibody based enzyme-linked immunosorbent assay (ELISA).


RESULTS
We found 10 to 100-fold increases in urine HNL/NGAL levels in about half of the patients 2 h after termination of the operation and elevated levels in all patients 72 h post operation. The urine levels of HNL/NGAL showed a weak, but significant relation with kidney function as measured by plasma levels of cystatin C or creatinine. The 2 h-HNL/NGAL levels were positively correlated to extracorporeal circulation time (p<0001). The assays were well correlated, but had different clinical performances.


CONCLUSIONS
We confirmed that urine HNL/NGAL may be a useful early biomarker of postoperative kidney injury. The results indicate that the antibody configuration of the assay has an impact on the clinical performance of the assay.
Department of Preventive Veterinary Medicine, Molecular Immunology and Pathogenic Microorganism, Jilin University, 130062 Changchun, PR China.
Linjun
L
Cai
Jan
J
Borowiec
Shengyuan
S
Xu
Wenyu
W
Han
Per
P
Venge
D000209:Acute-Phase Proteins / Q000737:chemistry / Q000652:urine*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000906:Antibodies / Q000276:immunology*; D000911:Antibodies, Monoclonal / Q000276:immunology; D005112:Extracorporeal Circulation; D005260:Female; D006801:Humans; D007668:Kidney / Q000293:injuries; D000071068:Lipocalin-2; D054834:Lipocalins / Q000737:chemistry / Q000652:urine*; D008297:Male; D008875:Middle Aged; D008970:Molecular Weight; D009504:Neutrophils; D011518:Proto-Oncogene Proteins / Q000737:chemistry / Q000652:urine*; D011863:Radioimmunoassay / Q000379:methods*; D013903:Thoracic Surgery
D000209:Acute-Phase Proteins; D000906:Antibodies; D000911:Antibodies, Monoclonal; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D011518:Proto-Oncogene Proteins