3 %, 56.5 %, 58.8 %, and 58.5 % in 2007, 2008, 2009, and 2010 in the J-RBR. A recent report from a MAPK Inhibitor Library single center in Japan gave the rates as 77.8 % and 75.9 % between 1979 and 2008 and between 2004 and 2008, respectively . In the present report for the J-RBR, the peak distribution of age was
in the sixties in the combined data for 2009 and 2010. The difference in the rates of primary glomerular disease including IgAN may have been due to the higher mean ages of native biopsy cases in the J-RBR compared to the single center in this period (mean age, 46.7 vs. 40.8 years; age of the peak number, sixties vs. twenties), because the incidence of secondary glomerular disease increases in elderly patients, as reported previously . IgAN is still Selleck HDAC inhibitor the most frequently diagnosed disease in native kidney biopsies in Japan (33.0 %, 30.2 %, 31.6 %, and 30.4 % of cases in 2007, 2008, 2009, and 2010 in the Akt targets J-RBR) [1, 4–6] similar to other Asian countries [7, 8] and some European countries [9, 10]. The peak distribution of age ranges was the twenties in 2009 and thirties in 2010. In patients with IgAN, the majority (68.1 %) of renal biopsies were performed in CKD stages G1 and G2, with median proteinuria less than 1 g per day (Table 18), suggesting that there was a relatively early diagnosis of this
biopsy-proven disease. In the present clinical data, the degree of proteinuria increased with the progression of the CKD stage, and was more than 1 g per day for the median value in patients with CKD stages G4 and G5 (Tables 18, S1, S2). Previously, the best single predictor for renal deterioration was severe
proteinuria on urine dipstick testing (≥100 mg/dL), followed by hypoalbuminemia, mild hematuria, serum total protein levels, diastolic blood pressure, and histological grade, in a cohort study with 10 years follow-up from 1995 in Japan, the cohort of which exhibited a younger median age (27.7 years) and a peak distribution of age ranges in the teens [11, 12]. A recent report suggested that IgAN with nephrotic syndrome had a worse renal outcome compared to IgAN with non-nephrotic syndrome unless partial or complete remission was achieved . Further studies are necessary those to elucidate the risk factors or predictors for renal deterioration in IgAN in the present era utilizing the J-RBR, possibly as part of a new secondary clinical study. MN was the most common histopathology in terms of primary glomerular disease other than IgAN in 2007 (31.4 %), 2008 (25.7 %), and 2009 (30.1 %) in the J-RBR and was also the most common type in primary nephrotic syndrome in 2007 (44.0 %) and 2009 (40.3 %) in the J-RBR. MN was also the most common primary cause of nephrotic syndrome in a northern European Caucasian population, with a biopsy rate of 4.5 per million population per year . A total of 68.7 % and 68.8 % of primary MN cases exhibited nephrotic syndrome as the clinical diagnosis at the time of renal biopsy in 2009 and 2010 in the J-RBR.