Higher apoptotic cell rate in Balkan endemic nephropathy--stereologic analysis

The aim of this study was to correlate apoptotic cell rate from different nephron segments between control group and groups of patients with Balkan endemic nephropathy (BEN). Kidney specimens of20 patients with clinically and epidemiologically confirmed BEN were compared with biopsy material of 10 patients (group I, non BEN) without glomerular or tubulointerstitial disease. Out of 20 patients with BEN, 10 suffered and died from BEN (group II, BEN) and 10 patients (group III, BEN/CV) suffered from BEN but died from cardiovascular disease. Patient age ranged from 40 to 50 years. The apoptotic cell rate was measured in proximal and distal tubules and in collecting ducts using the 40X objective with a calibrated eyepiece multipurpose M 42 test system according to Weibel. Comparison of all three nephron segments yielded statistically significant differences in volume density of apoptotic cells in proximal tubules and in collecting ducts among all three patient groups (non BEN vs. BEN, non BEN vs. BEN/CV and BEN vs. BEN/CV, P<0.001 all). Statistically significant difference in apoptotic cell rate was also found in distal tubules between non BEN and BEN groups and non BEN and BEN/CV groups, but not between BEN and BEN/CV groups. Our results showed a statistically significant increase of apoptotic cells in all three nephron segments in patients with BEN (BEN and BEN/CV) compared to control group. The highest number of apoptotic cells was found in distal tubules in the groups of patients with BEN and BEN with coexisting cardiovascular disease, suggesting that these cells might be most frequently and most severely injured in patients with BEN.