Urine ochratoxin a and sphinganine/sphingosine ratio in residents of the endemic nephropathy area in Croatia.

The most plausible theory of the aetiology of endemic nephropathy links it with exposure to nephrotoxic mycotoxin ochratoxin A (OTA). In this study, the concentration of OTA and sphinganine/sphingosine (Sa/So) ratio, the biomarker of another nephrotoxic mycotoxin fumonisin B1 exposure, were analysed in 45 human urine samples collected in the endemic village of Kaniza in Croatia and in 18 samples from control village. Samples were collected twice from the same persons in 2000 and 2005. In both years the frequency of OTA-positive samples was higher in Kaniza (43 % and 18 %, respectively) than in the control village (28 % and 6 %, respectively). OTA concentrations in samples collected in Kaniza were higher in 2000 than in 2005 (p<0.005). Although in both years Sa/So ratio was higher in Kaniza, the difference from the control group was not statistically significant. No control sample contained OTA and had the Sa/So ratio >1 at the same time, while in Kaniza four such samples were collected in 2000 and one in 2005.