FACTA UNIVERSITATIS Series: Medicine and Biology Vol.9, No 1, 2002, pp. 53 - 56 UC 616.61-004 ARISTOLOCHIC ACID AS A RISK FACTOR FOR BALKAN ENDEMIC NEPHROPATHY Heinz H. Schmeiser 1 , Volker M. Arlt 2 , Dusan Ferluga 3 , Marie Stiborova 4 , Annie Pfohl-Leszkowicz 5 , Mato Vukelic 6 , Stjepan Ceovic 6 , Jean-Pierre Cosyns 7 1 Division of Molecular Toxicology, German Cancer Research Center, Heidelberg, Germany 2 Section of Molecular Carcinogenesis, Institute of Cancer Research, Cotswold Road, Sutton, Surrey SM2 5NG, UK 3 Institute of Pathology, University of Ljubljana, Ljubljana, Slovenia 4 Department of Biochemistry, Charles University, Prague, The Czech Republic 5 Ecole Nationale Supérieure Agronomique de Toulouse, Laboratoire de Toxicologie et Sécurité Alimentaire, Auzeville Tolosane, France 6 Department of Pathology, General Hospital "Dr. J. Bencevic", Slavonski Brod, Croatia 7 Department of Pathology, Université Catholique de Louvain, Medical School, Brussels, Belgium E-mail: h.schmeiser@dkfz.de Summary. Background/Aims: Aristolochic acid nephropathy (AAN) is a unique type of rapidly progressive interstitial fibrosis, associated with urothelial cancer and related to the prolonged intake of Chinese herbal remedies (Aristolochia species) containing nephrotoxic and carcinogenic aristolochic acid (AA). On both clinical and morphological grounds, AAN is very similar to another fibrosing nephropathy, the Balkan endemic nephropathy (BEN), including the association with urothelial tumours. It has been suggested that the mycotoxin ochratoxin A (OTA) is associated with BEN, but also AA was considered as a possible causal factor in BEN already in the 1970s. Methods: We assessed AA exposure in endemic areas for BEN using the 32 P-postlabelling method. To this end we analysed renal tissue from three female farmers who lived in endemic areas and in two of whom an upper urinary tract cancer had developed, for OTA-related and AA-DNA adducts, described biomarkers of exposure for both genotoxins. Results: In two of the three cases of whom one had urothelial malignancy, the major adenosine adduct of aristolochic acid I, 7-(deoxyadenosin-N 6 -yl)-aristolactam I (dA-AAI), the most abundant AA-DNA adduct found in AAN patients, was identified by cochromatographic analyses on TLC and HPLC. In the same two patients OTA-related DNA adducts were detected. In the third patient, the tentatively assigned dA-AAI-DNA adduct spot was very faint and precluded complete identification. OTA-related DNA adducts were absent. Our data confirm the potential role of OTA in the development of urinary tract tumours in endemic regions and clearly demonstrate that people living in endemic areas for BEN have been exposed to AA, too. Conclusions: Thus, AA should be considered as an additional potential risk factor. The epidemiology of AAN and AAN-associated urothelial malignancies might provide a clue to urothelial malignancies in endemic areas. Whether AA plays a role also in BEN remains to be further assessed in patients with definite diagnosis of BEN and in patients with other nephropathies but living in endemic areas for BEN. Key words: Balkan endemic nephropathy, DNA adducts, aristolochic acid, 32 P-postlabeling Abbreviations: AA, aristolochic acid; AAI, aristolochic acid I (8-methoxy-6-nitrophenanthro[3,4-d]-1,3-dioxolo-5- carboxylic acid); dA-AAI, 7-(deoxyadenosin-N 6 -yl)-aristolactam I; CHN, Chinese herbs nephropathy; AAN, aristolochic acid nephropathy; BEN, Balkan endemic nephropathy; OTA, ochratoxin A So-called Chinese herbs nephropathy (CHN), asso- ciated with the ingestion of herbal remedies containing aristolochic acid (AA), was first reported in young Bel- gian women who have been on a slimming regimen including the Chinese herb Aristolochia fangchi (1,2). CHN is a unique rapidly progressive nephropathy char- acterised by extensive renal interstitial fibrosis, tubular proteinuria, early and severe anemia and a high risk of urothelial cancer (3-6). AA is a mixture of structurally related nitrophenanthrene carboxylic acids with aris- tolochic acid I (AAI) being the major component. AA is nephrotoxic in several species, mutagenic in bacteria and carcinogenic in rodents (7-10). The detection of specific AA-DNA adducts by 32 P-postlabelling in kid-