Pattern of biopsy-proven renal disease in a single center of south India: 19 years experience

The prevalence of biopsy-proven glomerulonephritis varies according to the geographic area, socioeconomic condition, race, age, demography and indication of renal biopsy. This study analyzed the distribution of biopsy-proven renal disease (BPRD) and its changing pattern over a period of 19 years from a tertiary care hospital in south India. All the renal biopsies performed from 1990 to 2008 were reviewed retrospectively. Biopsies were evaluated by light microscopy and immunofluorescence microscopy and also special stains when warranted. A total of 1849 biopsies were analyzed. The mean patient age was 32.27 ± 18.38 (range 10-80) years. The male:female ratio was 1.4:1. The most common indications of renal biopsy were nephrotic syndrome (49%), followed by chronic renal failure (13.6%) and rapidly progressive renal failure (12%). Primary glomerulonephritis (PGN) comprised 1278 (69.1%) of the total patients. Among the PGN cases, the most common one was minimal change disease (21.8%), followed by focal segmental glomerulosclerosis [FSGS (15.3%)], membranous glomerulonephritis (10%), chronic glomerulonephritis (9.7%), postinfectious glomerulonephritis (8.1%), mesengioproliferative glomerulonephritis (7.5%), diffuse proliferative glomerulonephritis (6.7%), crescentic glomerulonephritis (6.5%), IgA nephropathy [IgAN (6.3%)], membranoproliferative glomerulonephritis (5.7%), focal proliferative glomerulonephritis (1.6%) and IgM nephropathy (0.5). Secondary glomerular disease (SGN) accounted for 337 (18.2%) of the cases. The most common SGN was lupus nephritis (80.1%), followed by amyloidosis (8%) and diabetic nephropathy (6.5%). Tubulointerstitial disease [124 (6.7%)] and vascular disease [60 (3.2%)] were less common. End-stage changes and miscellaneous disease were found in 37 (2%) and 13 (0.7%) cases, respectively. The incidence of FSGS and IgAN has been increasing since 1999. This study provides descriptive biopsy data and highlights the changing incidence of renal disease which is probably contributed by an increase referral due to increased awareness together with increased manpower and infrastructure.