This CDSS provides useful additional information for identifying 'high-risk' IgAN patients and may help stratify them in the context of a personalized medicine approach.

Background: Predicting outcome in individual patients with IgA nephropathy (IgAN) is difficult but important. For this purpose, the absolute renal risk (ARR) model has been developed in a French cohort to calculate the risk of end-stage renal disease (ESRD) and death. ARR (0-3) is scored in individual IgAN patients based on the presence of proteinuria ≥1 g/24 h, hypertension, and severe histopathological lesions (1 point per risk factor). We have validated the ARR model in a Norwegian cohort of IgAN patients and tested whether adding data on initial estimated glomerular filtration rate (eGFR) and age improved prediction. Methods: IgAN patients diagnosed between 1988 and 2012 were identified in the Norwegian Kidney Biopsy Registry, and endpoints were identified by record linkage with the Norwegian Renal Registry (ESRD) and the Population Registry (deaths). Results: We identified 1,134 IgAN patients. The mean duration of follow-up was 10.2 years (range 0.0 to 25.7 years). Two hundred and fifty one patients developed ESRD and there were 69 pre-ESRD deaths. The ARR model significantly stratified the IgAN cohort according to risk of ESRD/death. The inclusion of eGFR and age significantly improved the ARR prognostic model; in the receiver operator characteristics (ROC) analysis, area under the curve (AUC) at 10-years of follow-up increased from 0.79 to 0.89, p < 0.001. Conclusions: ARR is a suitable prognostic model for stratifying IgAN patients according to the risk of ESRD or death. Including initial eGFR and age in the model substantially improved its accuracy in our nationwide cohort.

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FederationIntroduction and Aims: Loss of podocytes in primary glomerulopathies is crucial for glomerulosclerosis progression which leads to end-stage renal failure in such patients. The mechanism of direct replacement of injured podocytes does not exist so the only way to compensate the integrity of glomerulus is change of cells shape to cover the glomerular tuft with a smaller number of podocytes. Foot process effacement is the typical morphological sign of podocyte respond to stress. Podocyte detachment (PD) from glomerular basement membrane (GBM) develops when podocyte hypertrophy is unsufficient. The aim of investigation was estimation of relationship between range of foot process width (FPW), PD and level of daily proteinuria in patients with primary variants of glomerulopathies. Methods: 42 patients with biopsy proven primary glomerulopathies were included in the study. According to the the results of light and electron microscopy 17 (40,5%) patients had membranous nephropathy, 8 (19,0%) -focal segmental glomerulosclerosis, 12 (28,6%) -minimal change disease and 5 (11,9%) -proliferative variants of glomerulonephritis (2-IgA-nephropathy, 3 -membrano-proliferative glomerulonephritis). Standart laboratory and instrumental investigations were perfomed. Samples of serum and urine were obtained in the day of byopsy. FPW and PD were measured using Image J software (NIH, 1997). FPW was counted as ratio of GBM length to amount of foot processes in every electronogramm using correction factor π/4 as described in previous works. PD was calculated as percentage of bare areas of GBM. Results: There were no statistically significant differences between FPW and PD in patients with different forms of glomerulopathies ( p>0,05). There was negative correlation between 31, p<0,05). Daily proteinuria rate positively correlated with FPW (r=0,52, p<0,05) while inverted relation with level of PD was found (r=-0,36, p<0,05). The same pattern was detected comparing groups of patients with and without nephrotic syndrome. The level of daily proteinuria was higher in patients with more expressed hyaline droplet degeneration of tubular epithelial cells. Conclusions: Unlike data published in recent works we found no difference of FPW and PD rate in patients with different forms of glomerulonephritis. Strong positive correlation of FPW with proteinuria range confirms the role of podocytes in development of high proteinuria and nephrotic syndrome, considering that there were no abnormalities in tubular reabsorbtion of protein. Interestingly the detachment of podocytes from GBM does not increase proteinuria range, more over inverse relationship was detected. Probably this fact can be explained by unknown mechanisms of transcellular transport of protein rather than directly through bare parts of GBM. Nagoya University Graduate School of Medicine, Nagoya, Japan Introduction and Aims: The clinicopathological characteristics of PLA2R-related membranous nephropathy (MN) in Japan remain unclear. Methods: We studied retrospectively the outcomes ...