Renal biopsy findings in Belgium: a retrospective single center analysis

Renal biopsy is the definitive diagnostic test in patients with renal parenchymal disease. Renal biopsy registry is an important tool which can provide valuable data concerning early and correct epidemiological description and clinical correlations of renal diseases. Records of 326 adult renal biopsies performed at our hospital from January 1991 till the end of December 2006 were retrospectively examined. Overall, secondary glomerular diseases (SGD) were predominant (39.9%), followed by primary glomerular diseases (PGD) (30.4%), vascular diseases (13.2%) and TIN (6.7%). Total sclerosis of the kidney did not allow histopathological diagnosis in 5.8% of all biopsied kidneys. Focal and Segmental Glomerular Sclerosis (FSGS), IgA Nephropathy (IgAGN) and Minimal Change Disease (MCD) and Membranous Glomerulopathy (MGN) were the most common PGD, altogether representing 75.7% of all PGD. FSGS was the most frequent (30.3%), followed by IgAGN (21.2%), MCD (19.1%) and MGN in 15.1%. Vasculitis, HIVAN, diabetic nephropathy and amyloidosis were the most common SGD, altogether representing 90% of all SGD. Immune Mediated Glomerulonephritis (IMGN) were the most frequent (32.3%), followed by HIVAN (16.9%), diabetic nephropathy (14.6%) and amyloidosis (10%). Nephroangiosclerosis (benign and malignant nephroangiosclerosis) was the most frequent vascular nephropathy responsible for 79% of all vascular diseases. Thrombotic microangiopathy was seen in 9.3% and atherothrombotic disease in 7% of all vascular diseases. Concerning tubular diseases, chronic TIN accounted for 63.6% of all tubular diseases, followed by light chain-cast nephropathy (22.7%) and acute TIN (13.6%). Because of lack of material, 3.4% of all biopsies could not be analyzed. These data demonstrate that the distribution of biopsy-proved renal diseases in a Belgian population of the Brussels area is strongly influenced by the indications of renal biopsy. Harmonization of these indications might reflect with more accuracy the actual incidence of different nephropathies in a given population. Nation and worldwide renal biopsy registers are important to follow patterns of renal diseases in different populations. This information is important not only for health organizations in order to plan health budget but also for helping clinicians to provide a better care to patients.