This manuscript describes the use of ultrasound elastography, with the exception of liver applications, and represents an update of the 2013 EFSUMB (European Federation of Societies for Ultrasound in Medicine and Biology) Guidelines and Recommendations on the clinical use of elastography.

The present data are an important contribution to the epidemiology of renal diseases in Europe, highlighting not only numerous similarities but also significant epidemiological differences in Western and Central European countries, particularly a higher, albeit declining, incidence and prevalence of membranoproliferative GN. This report represents the basis for the future of Romanian Registry of Renal Biopsies and is intended to serve as a source of information for nephrologists concerned with East European renal pathology.

Aimto assess the inter-operator reproducibility of kidney shear wave speed, evaluated by means of Acoustic Radiation Force Impulse (ARFI) elastography, and the factors which influence it.MethodsOur prospective pilot study included 107 subjects with or without kidney pathology in which kidney shear wave speed was evaluated by means of ARFI elastography. Intraclass correlation coefficient (ICC) was used to assess ARFI elastography reproducibility.ResultsA strong agreement was obtained between kidney shear wave speed measurements obtained by the two operators: ICC = 0.71 (right kidney) and 0.69 (left kidney). Smaller ICCs were obtained in “healthy subjects”, as compared to patients with kidney diseases (0.68 vs. 0.75), in women as compared with men (0.59 vs. 0.78), in subjects younger than 50 years as compared with those aged at least 50 years (0.63 vs. 0.71), in obese as compared with normal weight and overweight subjects (0.36 vs. 0.66 and 0.78) and in case of measurements depth <4 cm or >6 cm as compared with those performed at a depth of 4–6 cm from the skin (0.32 and 0.60 vs. 0.81).ConclusionARFI elastography is a reproducible method for kidney shear wave speed assessment.

BackgroundThere is an ongoing debate as to whether early diabetic nephropathy in Type 2 diabetes mellitus may be attributed to the glomerulus or to the proximal tubule. Urinary excretion of nephrin and vascular endothelial growth factor may increase even in the normoalbuminuria stage. In the course of diabetic nephropathy, the proximal tubule may be involved in the uptake of urinary nephrin and vascular endothelial growth factor.Materials and MethodsTwo groups of consecutive Type 2 diabetes mellitus outpatients (38 normo-, 32 microalbuminuric) and 21 healthy subjects were enrolled in a cross-sectional study and evaluated concerning the relation of proximal tubule dysfunction with the podocyte biomarkers excretion, assessed by ELISA methods. The impact of advanced glycation end-products on this relation was also queried.ResultsUrinary alpha1-microglobulin and kidney injury molecule-1 correlated with urinary albumin:creatinine ratio (R2 = 0.269; p<0.001; R2 = 0.125; p<0.001), nephrinuria (R2 = 0.529; p<0.001; R2 = 0.203; p<0.001), urinary vascular endothelial growth factor (R2 = 0.709; p<0.001; R2 = 0.360; p<0.001), urinary advanced glycation end-products (R2 = 0.578; p<0.001; R2 = 0.405; p<0.001), serum cystatin C (R2 = 0.130; p<0.001; R2 = 0.128; p<0.001), and glomerular filtration rate (R2 = 0.167; p<0.001; R2 = 0.166; p<0.001); nephrinuria and urinary vascular endothelial growth factor correlated with urinary albumin:creatinine ratio (R2 = 0.498; p<0.001; R2 = 0.227; p<0.001), urinary advanced glycation end-products (R2 = 0.251; p<0.001; R2 = 0.308; p<0.001), serum cystatin C (R2 = 0.157; p<0.001; R2 = 0.226; p<0.001), and glomerular filtration rate (R2 = 0.087; p = 0.007; R2 = 0.218; p<0.001).ConclusionsIn Type 2 diabetes mellitus there is an association of proximal tubule dysfunction with podocyte damage biomarkers, even in the normoalbuminuria stage. This observation suggests a potential role of the proximal tubule in urinary nephrin and urinary vascular endothelial growth factor processing in early diabetic nephropathy, a fact which could be related to advanced glycation end-products intervention. Podocyte damage and proximal tubule dysfunction biomarkers could be validated as a practical approach to the diagnosis of early diabetic nephropathy by further studies on larger cohorts.

Kidney shear wave speed values obtained by ARFI elastography decrease with the decrease in the estimated GFR.