Background: Serum creatinine is suboptimal as a biomarker in the early diagnosis of contrast-induced nephropathy (CIN). In this study, we investigated a panel of novel biomarkers in the early diagnosis of CIN and in assessing patient outcomes.
Methods: This single-centre, nested, prospective case-controlled study included 30 patients with CIN and 60 matched controls. Serum and urine samples were collected before contrast administration and at 24 hours, 48 hours, and ≥5 days after contrast administration. Concentrations of NGAL, cystatin C, β 2M, IL18, IL10, KIM1, and TNFα were determined using Luminex and ELISA assays. Outcomes were biomarker diagnostic discrimination performance for CIN and mortality after generation of area under receiver operating characteristic curves (AUROCs).
Results: Median serum levels for 24 h cystatin C (p < 0.01) and 48 h β 2M levels (p < 0.001) and baseline urine NGAL (p=0.02) were higher in CIN patients compared to controls with AUROCs of 0.75, 0.78, and 0.74, respectively, for the early diagnosis of CIN. Serum β 2M levels were higher in CIN patients at all time points. Elevated baseline serum concentrations of IL18 (p < 0.001), β 2M (p=0.04), TNFα (p < 0.001), and baseline urine KIM (p=0.01) and 24 h urine NGAL (p=0.02) were significantly associated with mortality. Baseline serum concentrations of IL18, β 2M, and TNFα showed the best discrimination performance for mortality with AUROCs, all >0.80. Baseline NGAL was superior for excluding patients at risk for CIN, with positive and negative predictive ranges of 0.50-0.55 and 0.81-0.88, respectively. Cystatin C (p=0.003) and β 2M (p=0.03) at 24 h independently predicted CIN risk. β 2M predicted increased mortality of 40% at baseline and 50% at 24 hours.
Conclusion: Serum cystatin C at 24 h was the best biomarker for CIN diagnosis, while baseline levels of serum IL18, β 2M, and TNFα were best for predicting prognosis.
Copyright © 2020 Justor Banda et al.