Research Highlight

Biomarkers to detect acute kidney injury 

doi:10.1038/nindia.2014.78 Published online 4 June 2014

The dye used in coronary angiography could induce acute kidney injury.

BSIP SA / Alamy

Doctors use an iodinated dye to measure blood flow in the cardiac arteries of patients undergoing coronary angiography. The dye induces acute kidney injury in some patients. Researchers have now found that increased levels of two markers in the blood serum could signal the onset of such injury1. The biomarkers -- neutrophil gelatinase-associated lipocalin and cystatin C -- could thus potentially be used in diagnosing acute kidney injury in such patients.

Dye-induced acute kidney injury is usually diagnosed by measuring serum creatinine levels 48–72 hours after angiography. However,  this might be quite late to start treating the injury. 

To devise a faster technique, the researchers determined the optimum cut-off serum levels of lipocalin and cystatin C in patients taking an angiography followed by angioplasty. They measured the serum levels of lipocalin, cystatin C and creatinine at 0, 4, 24 and 48 hours in 30 patients with acute kidney injury and 30 healthy individuals.

The researchers found that the serum levels of lipocalin increased rapidly 4 hours after angiography and angioplasty and then dropped to near normal levels after 48 hours in patients with kidney injury. Serum cystatin C levels peaked at 24 hours and remained high until 48 hours. In healthy individuals, the biomarkers remained static. 

The researchers say that serum lipocalin and cystatin C may be used to diagnose acute kidney injury in patients undergoing coronary angiography and angioplasty.

References

1. Padhy, M. et al. Serum neutrophil gelatinase associated lipocalin (NGAL) and cystatin C as early predictors of contrast-induced acute kidney injury in patients undergoing percutaneous coronary intervention. Clin. Chim. Acta 435, 48–52 (2014) doi: 10.1016/j.cca.2014.04.016