#4204 MULTIPARAMETRIC MAGNETIC RESONANCE IMAGING BIOMARKERS OUTPERFORM LAB BIOMARKERS FOR PREDICTING PROGRESSION OF DIABETIC KIDNEY DISEASE

Abstract

Abstract Background and Aims We recently showed that comprehensive non-contrast multiparametric Magnetic Resonance Imaging (mpMRI) allowed functional and structural assessment of diabetic kidney disease (DKD) and that an imaging endpoint, R1 cortex, showed significant predictive property for progression of DKD. We further investigated the performance of other MRI and lab biomarkers for predicting disease progression. Method In this prospective study, 38 DKD subjects aged 18–79 years and 20 age- and gender-matched healthy volunteers (HV) were included at baseline. 31 DKD subjects (2 stage 2, 13 stage 3, 14 stage 4, and 2 stage 5) and 17 HV were re-examined at 2 years ± 6 months. Clinical and lab examination, iohexol clearance for measured glomerular filtration rate (mGFR), urine albumin:creatinine ratio (UACR) and mpMRI were performed at both visits. A wide range of MRI biomarkers associated with kidney hemodynamics, oxygenation and macro/microstructure were included for evaluation. Disease progression was defined by at least one of the following at 2 years: decrease in mGFR slope of >5 mL/year/1.73 m2; worsening UACR category; or any major adverse kidney event defined as sustained decrease in eGFR of >40%; doubling of serum creatinine from baseline; development of kidney failure with mGFR <15 ml/min/1.73 m2; or death from renal cause. Univariable logistic regression analyses were performed to discriminate between progressors and non-progressors using each relevant lab and imaging endpoint as a predictor variable. Results Mean 2-year mGFR decline (ml/min/1.73 m2) in DKD patients was -2.7± 5.4 and in HV -1.9 ± 10.7. 13/31 (42%) DKD subjects and 4/17 (24%) HV progressed. Key lab biomarkers are shown in Table 1 and MRI biomarkers in Table 2. Conclusion Of all analyzed biomarkers, only the imaging biomarker R1 cortex, which reflects molecular environment viscosity, fibrosis, and inflammation (interstitial oedema, cellular swelling) showed significant predictive property for progression of DKD. UACR trended towards significance but was not statistically significant. R1 cortex outperformed all other imaging and lab biomarkers, but further studies with R1 cortex as a pre-specified endpoint are required to confirm these results.