title: Serum neutrophil gelatinase associated lipocalin (NGAL) and cystatin C as early predictors of contrast-induced acute kidney injury in patients undergoing percutaneous coronary intervention.
abstract: BACKGROUND
  Contrast-induced acute kidney injury (AKI) is diagnosed by estimating serum creatinine at 48-72h after diagnostic or interventional coronary angiography. It is too late for an early intervention. Neutrophil gelatinase associated lipocalin (NGAL) and cystatin C are novel markers of AKI. We determined the optimum cut-off level of NGAL and cystatin C in early diagnosis and prediction of AKI in patients undergoing coronary angiography followed by angioplasty.
  
  
  METHODS
  In a nested case control study, serum NGAL, cystatin C by ELISA and serum creatinine by Jaffe's kinetic method were estimated at 0, 4, 24 and 48h of coronary angiography followed by angioplasty in 30 cases who developed contrast-induced AKI and 30 subjects who did not develop AKI. eGFR was estimated for both cases and controls by the MDRD equation. ROC was used to determine the optimum cut-off.
  
  
  RESULTS
  Serum NGAL increased sharply at 4h after the procedure and then gradually declined to near normal level at 48h in AKI cases. The rise in cystatin C peaked at 24h and then declined but remained high till 48h. In controls, they remained static. The optimum cut-off of serum NGAL and cystatin C was 155.2ng/ml and 0.517mg/l respectively at 4h and 89.5ng/ml and 0.99mg/l respectively at 24h of angiography. Odds ratio for hypertensives to develop AKI was 3.57 (CI: 1.2-11.1, p=0.03).
  
  
  CONCLUSIONS
  Serum NGAL and cystatin C may act as early markers of contrast-induced AKI in patients undergoing percutaneous coronary intervention. Patients with hypertension are susceptible to develop contrast-induced AKI.
authors.affiliation: Department of Biochemistry, Maulana Azad Medical College, New Delhi 110002, India.
authors.forename: Mamta
authors.initials: M
authors.lastname: Padhy
authors.affiliation: Department of Biochemistry, Maulana Azad Medical College, New Delhi 110002, India.
authors.forename: Smita
authors.initials: S
authors.lastname: Kaushik
authors.affiliation: Department of Cardiology, GB Pant Hospital, New Delhi 110002, India.
authors.forename: M P
authors.initials: MP
authors.lastname: Girish
authors.affiliation: Department of Biochemistry, Maulana Azad Medical College, New Delhi 110002, India.
authors.forename: Sudhesna
authors.initials: S
authors.lastname: Mohapatra
authors.affiliation: Department of Biochemistry, Maulana Azad Medical College, New Delhi 110002, India.
authors.forename: Seema
authors.initials: S
authors.lastname: Shah
authors.affiliation: Department of Biochemistry, Maulana Azad Medical College, New Delhi 110002, India. Electronic address: bckoner@hotmail.com.
authors.forename: Bidhan Chandra
authors.initials: BC
authors.lastname: Koner
mesh_terms: D058186:Acute Kidney Injury / Q000097:blood* / Q000139:chemically induced* / Q000175:diagnosis; D000209:Acute-Phase Proteins; D003287:Contrast Media / Q000009:adverse effects*; D017023:Coronary Angiography / Q000009:adverse effects; D055316:Cystatin C / Q000097:blood*; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D000071068:Lipocalin-2; D054834:Lipocalins / Q000097:blood*; D008297:Male; D008875:Middle Aged; D062645:Percutaneous Coronary Intervention / Q000009:adverse effects*; D011518:Proto-Oncogene Proteins / Q000097:blood*; D013997:Time Factors
chemical_list: D000209:Acute-Phase Proteins; D003287:Contrast Media; D055316:Cystatin C; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D011518:Proto-Oncogene Proteins
keywords: Acute kidney injury; Angiography; Cystatin C; NGAL