Epidemiology of renal disease in Romania: a 10 year review of two regional renal biopsy databases

Background. Epidemiological data of renal disease are available from large national renal biopsy registries from Central and Western European countries; in contrast, detailed epidemiological data from Eastern European countries are missing. This report is the first review of histological data, over a period of 10 years (1995-2004), covering a population of over 6 million inhabitants and two distinct regions from an East European country - Romania. Methods. 635 eco-guided kidney biopsies from the Moldova (North-Eastern Romania, 8 counties, 4 754 048 inhabitants) and Banat (Western Romania, 3 counties, 1 454 747 inhabitants) regions were analysed. Data on serum creatinine concentration (sCr), 24 h proteinuria, haematuria, clinical diagnosis, histological diagnosis and complications after renal biopsy were collected. Results. The number of biopsies performed varied between 10.9 p.m.p./year in 1995 and 11.3 p.m.p./year in 2004. The most common clinical syndromes - as indication for performing the renal biopsy - were: nephrotic syndrome (52.3%), followed by nephritic syndrome (21.9%), acute renal failure (ARF) (12.4%), chronic kidney disease (CKD) (10.2%) and asymptomatic urinary abnormalities (AUA) (3.3% of the cases). The major histological groups identified were: primary glomerulonephritis (GN) (66.2%), secondary GN (26.4%), vascular nephropathies (2.3%), and tubulointerstitial nephropathies (TIN) (1.5%) of the cases. Among primary GN's, the most frequent diagnoses were: membranoproliferative GN (MPGN) (29.4%, incidence in 2004 - 9.3 p.m.p./year), mesangioproliferative GN (MesGN) (28.9%, incidence - 10 p.m.p./year), membranous GN (MGN) (11.2%, incidence - 5.3 p.m.p./year), minimal change disease (MCD) (8.5%, incidence - 7.3 p.m.p./year), focal and segmental glomerulosclerosis (FSGS) (11.5%, incidence - 3.3 p.m.p./year) and crescentic GN (CGN) (7.9%, incidence - 3.3 p.m.p./year). The prevalence of membranoproliferative GN significantly decreased from 1995 to 2004. The prevalence of different types of secondary GN was similar to Western and Central European countries, with the particular difference of higher infectious diseases associated GN. Conclusion. The present data are an important contribution to the epidemiology of renal diseases in Europe, highlighting not only numerous similarities but also significant epidemiological differences in Western and Central European countries, particularly a higher, albeit declining, incidence and prevalence of membranoproliferative GN. This report represents the basis for the future of Romanian Registry of Renal Biopsies and is intended to serve as a source of information for nephrologists concerned with East European renal pathology.