Background: The outcome for Balkan endemic nephropathy (BEN) patients diagnosed in 1992 was analyzed in 2006 with the aim of detecting factors associated with disease progression and patient outcome.
Methods: In 1992 BEN was detected in 119 patients (53 males, 56.9 +/- 13.8 years) from the village of Sopic. Changes in creatinine clearance as well as outcome (death or onset of regular hemodialysis) were analyzed retrospectively in 2006.
Results: During the 14-year period 47 patients deceased (5 on hemodialysis) at the mean age of 72.2 +/- 8.2 years, while no data were available for 13 cases. Out of 59 remaining patients 3 were on hemodialysis in 2006 and 56 participated in the control examination. Of these 12 had creatinine clearance at least 50% lower than in 1992 and 44 had unchanged creatinine clearance. Logistic regression revealed age and proteinuria, but linear regression only age as significant prognostic factors for changes in creatinine clearance. The all-cause mortality rate varied between 1.1 and 5.3% per year and was similar to the mortality rate of the general population. The main cause of death was cardiovascular disease (40.5%) followed by malignant diseases (17%), most frequently (11%) due to upper urothelial tumors. Urine protein and age were found to be a significant independent predictor of all-cause mortality.
Conclusion: In the village of Sopic BEN was commonly detected in patients in their fifties, progressed slowly, but most patients died from other causes at old age before end-stage renal disease occurred. Kidney function remained stable over the decade in three quarters of the surviving patients. Age and proteinuria were found to be prognostic factors for both disease progression and patient mortality.