Open questions on Balkan nephropathy.

Abstract

The prevalence of the disease was stable over manyyears, but now appears to decline in most affectedsettlements w1x. Some authors also suggest that theincidence of BEN decreases w1,2x and that it appearsto be tapering off; others, however, describe a stableincidence of BEN w3x. The question arises on differentepidemiological characteristics of the disease in dif-ferent endemic regions. In search of an answer tothis question a retrospective analysis of the incidenceof haemodialysis BEN patients was undertaken infour haemodialysis centres situated in three differ-ent endemic regions over the period 1991–2000.The medical files of haemodialysis patients treatedin Lazarevac (Kolubara River), Nis and Leskovac(South Morava River) and Pozarevac (Pek River) wereused in this study. The incidence of haemodialysispatients with BEN from endemic villages was com-pared with the incidence of patients suffering fromother renal diseases from the same endemic villages.Non-standardized rates per 1000 inhabitants werecalculated.The incidence of BEN patients in ESRD, whostarted haemodialysis, was different in three endemicregions already known as differently affected endemicfoci. However, during the last decade the incidence ofhaemodialysis BEN patients remained stable in allthree regions (Figure 1a). In the same period, theincidence of haemodialysis patients suffering fromother renal diseases and living in the same endemicvillages (mean incidence for three regions 0.035–0.28)was lower than the incidence of BEN patients onhaemodialysis (0.22–0.58) (Figure 1b). These resultscorrespond with those reported by Cukuranovic et al.w4x but these authors pointed out a marked decreaseof the incidence of BEN in end-stage renal disease(ESRD) in the last 10 years as compared with theprevious decade. BEN is a slowly progressive dis-ease and patients usually start haemodialysis in theirsixties. Therefore, although our data demonstrate astable incidence of BEN in ESRD it only indicatesthat BEN is preserved. In order to answer the ques-tion above, monitoring of the incidence of BEN in theearly stage is more important. A recent study in theKolubara River area has discovered new BEN orBEN-suspected cases and the authors consider thatBEN is not tapering off w5x. However, early diagnosisof BEN is associated with the following unsolvedquestions on BEN—criteria for a correct diagnosis.