Balkan endemic nephropathy: role of ochratoxins A through biomarkers.

Several studies implicated mycotoxins, in endemic kidney disease geographically limited to Balkan region (Balkan endemic nephropathy (BEN)). In Bulgaria, much higher prevalence of ochratoxin A (OTA), exceeding 2 microg/L, was observed in the blood of affected population. OTA is found more often in the urine of people living in BEN-endemic villages. To confirm and quantify exposure to OTA in Vratza district, we followed up OTA intake for 1 month, OTA in blood and urine from healthy (20-30 years old) volunteers, from two villages with high risk for BEN disease. Food samples were collected daily, blood and urine at the beginning of each week. Relations between increasing OTA intake, blood concentration and elimination of OTA in urine have been studied in rats. Average weekly intake of OTA varies from 1.9 to 206 ng/kg body weight, twice tolerable weekly intake recommended by JECFA. OTA blood concentrations are in the same range as previously reported in this region with concentrations reaching 10 microg/L. Weekly OTA food intake is not directly correlated with blood and urine concentrations. Biomarkers of biological effects such as DNA adducts were detected in patients affected by urinary tract tumours (UTT) and in rat study. All these plead for the implication of OTA, in BEN and UTT.

Analysis of ochratoxin A in foods consumed by inhabitants from an area with balkan endemic nephropathy: a 1 month follow-up study.

In the 1950s, a series of publications from Bulgaria, Yugoslavia, and Romania locally described a kidney disease called Balkan Endemic Nephropathy (BEN). In Bulgaria, the exposure of populations to ochratoxin A (OTA) was supported by analysis of individual food items demonstrating a higher prevalence and higher levels of OTA in food from the high-incidence areas of BEN. In this work, food consumption from a series of individuals from two villages of the BEN area during 1 month was followed using the duplicate diet method. Meals consumed by volunteers from both villages showed uneven OTA contents, spreading from below the limit of quantification (<0.07 microg/kg) to 2.6 microg/kg. The average weekly intake of OTA varies from 1.86 to 92.7 ng/kg of body weight. Some of these levels approach the provisional tolerable weekly intake (PTWI) established by the JECFA at 100 ng/kg of body weight. These results confirm previous studies performed in the same area and demonstrate the high exposure of this population to OTA, thus strengthening the hypothesis of the involvement of this mycotoxin in BEN etiology.

3-Monochloro-1,2-propandiol (3-MCPD) in soy sauce from the Bulgarian market.

The 3-monochloro-1,2-propandiol (3-MCPD) levels in soy sauces which contained hydrolysed vegetable protein were evaluated for the Bulgarian market. For analysis of 3-MCPD, a gas chromatography-mass spectrometry (GC-MS) method was applied with a linear range of 0.03-2.00 µg mL⁻¹ and a limit of detection (LOD) of 2.3 µg kg⁻¹ and a limit of quantification (LOQ) of 3.4 µg kg⁻¹. At these levels, the standard deviation was 5.1%, with recoveries between 81% and 102%. The method was applied to the analysis of 21 samples of soy sauce from the Bulgarian market. Results ranged from 3.7 to 185.6 µg kg⁻¹. Soy sauces produced from hydrolysed soy protein contained higher levels of 3-MCPD than naturally fermented sauces. In 38.4% of samples of Bulgarian origin, the 3-MCPD content was above the EU limit of 20 µg kg⁻¹. In all analysed samples, 33.3% had a 3-MCPD content above the EU limit.