Significance of combined detection of Cys-C, NGAL and KIM-1 in contrastinduced nephropathy after coronary angiography

To evaluate the significance of combined detection of Cystatin-C (Cys-C), neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) in the diagnosis of contrast-induced nephropathy (CIN) after coronary angiography (CAG). Sixty-nine patients receiving CAG with high-risk of CIN (risk score not less than 6 or eGFR not more than 60ml/min) were enrolled in this study. Blood and urine samples were collected before and after CAG. Levels of Cys-C, NGAL and KIM-1 were determined by ELISA methods to further explore the specificity and sensitivity for the diagnosis of CIN. The results showed that maximum levels of serum Cys-C (r= 0.798，P<0.001), urine NGAL (r= 0.320, P = 0.007) and urine KIM-1(r= 0.418，P<0.001) post-CAG were positively correlated with the maximum levels of serum creatinine (SCr) post-CAG. The levels of Cys-C at 24h post-CAG (r= 0.840), NGAL at 3h post-CAG (r= 0.367) and KIM-1 (r= 0.458) at 12h post-CAG correlated with maximum SCr post-CAG most significantly. The changes of NGAL（r= 0.271, P = 0.020）and KIM-1（r= 0.230, P = 0.049）were positively correlated with the changes of SCr while Cys-C not. For the diagnosis of CIN, the specificity, sensitivity and AUC of NGAL were 93.9%, 66.7% and 0.659 while the specificity, sensitivity and AUC of KIM-1 were 95.2%, 75% and 0.742 respectively. In conclusion, NGAL and KIM-1 were valuable for CIN diagnosis after CAG. NGAL can indicate the diagnosis of CIN at 3 hours after CAG, while KIM-1 can indicate CIN at 12 hours after CAG more sensitively.