Trends, pathological classification of renal diseases proved by biopsy: A 10-year retrospective cohort study in an East Chinese Tertiary Center.

This study aimed to investigate regional epidemiological trends of chronic kidney disease (CKD) to elucidate their etiologies and inform the development of preventive and diagnostic strategies. We retrospectively analyzed 2100 hospitalized patients undergoing native renal biopsy from January 1, 2012, to December 31, 2021. The clinical presentation, the prevalence of nephropathy revealed by biopsy, the age-distribution differences of main pathological types, and changes in the prevalence of different diseases between period 1 (2012-2016) and period 2 (2017-2021) were further analyzed. Hematuria or proteinuria not within the range of the nephrotic syndrome (NS) (36.7%), NS (32.6%), chronic renal insufficiency (22.3%) and acute kidney injury (3.1%) were the 4 major clinical indications for renal biopsy. Although the proportion of primary glomerulonephritis (primary GN, from 85.0% to 75.9%) has shown a downward trend, it remained the predominant diagnosis, with secondary glomerulonephritis (secondary GN, from 11.2% to 16.5%) ranking second. Combined nephropathy showed a significant increase (from 0.3% to 2.6%) especially the diabetic nephropathy (DN) combined with other kidney diseases (from 0.2% to 1.8%). Among primary GN, IgA nephropathy (IgAN) was the most common type, followed by membranous nephropathy (MN). Although the proportion of IgAN did not change for the general population, among individuals aged 30-65, there was an upward trend. However, for secondary GN, DN increased significantly while lupus nephritis (LN) showed a downward trend. Additionally, there were significant differences in the age-distribution between DN and IgAN, DN and minimal change disease (MCD), IgAN and MN, and MN and MCD. The epidemiological trend of renal diseases has changed significantly over time. Although the proportion of primary GN has shown a downward trend, it remained the predominant component, with secondary GN ranking second, and combined nephropathy showing a significant increase. Among primary GN, IgAN was the most common type in the study, followed by MN. However, for secondary GN, from period 1 to period 2, DN gradually surpassed LN to become the most common disease type.