[Experimental and human nephrotoxicity induced by ochratoxins]

Ochratoxin A is a mycotoxin: a dihydroisocoumarin derivative linked to L. beta phenylalanine. Ochratoxin A is produced by a number of Aspergillus and Penicillium species. This mycotoxin is a carcinogenic, teratogenic, mutagenic and immunosuppressive substance. Ochratoxin A is a common contaminant found in a variety of foods for human nutrition as well as animal feeds. The aim of this study is to discuss nephrotoxic properties of this mycotoxin in humans. Nephrotoxicity has been reported in many animals after exposure to ochratoxin A. Porcine nephropathy due to this mycotoxin is a well known disease characterized by impairment of proximal renal function. Renal damage is also confined to the proximal tubule in other animal species. A good correlation is found between renal function abnormalities and the location of the lesions along the nephron. Of particular interest is the presence of nuclear abnormalities of the epithelial cells with pyknosis, karyorrhexis and karyomegaly. The question is to know if ochratoxin is nephrotoxic in humans. Acute nephrotoxicity seems to be very rare and we found only one case report suggesting such a possibility. We observed the occurrence of chronic renal failure in two patients with a possible responsibility of a chronic ochratoxin A intoxication. Clinical and histologic findings in these two patients were quite similar to those described in several cases of karyomegalic interstitial nephritis. Striking similarities between the changes in renal structure and function seen in ochratoxin A-induced experimental nephropathies and in Balkan endemic nephropathy suggest a common etiologic agent. This mycotoxin could be also responsible for interstitial nephropathies in North Africa.