Causes
Dietary exposure to aristolochic acid is the cause of BEN and its attendant transitional cell cancers. Former hypotheses that included roles for ochratoxin, poisoning by organic compounds leached from lignite or by heavy metals, viruses, and trace-element deficiencies, are not supported by current evidence. Genetic factors may be involved in determining which persons exposed to aristolochic acid suffer from BEN and which do not.In the Balkan region, dietary aristolochic acid exposure may come from the consumption of the seeds of Aristolochia clematitis (European birthwort), a plant native to the endemic region, which grows among wheat plants and whose seeds mingle with the wheat used for bread. Aristolochic-acid-containing herbal remedies used in traditional Chinese medicine are associated with a related—possibly identical—condition known as "Chinese herbs nephropathy".Exposure to aristolochic acid is associated with a high incidence of uroepithelial tumorigenesis. Diagnosis
History
The first official published description of the disease was made by the Bulgarian nephrologist Dr.Yoto Tanchev (1917–2000) and his team in 1956 in the Bulgarian Journal Savremenna Medizina, a priority generally acknowledged by the international nephrological community. Their study was based on a wide screening of inhabitants of the villages around the town of Vratsa, Bulgaria.
Their contribution to the understanding of this unusual endemic disease of the kidneys was their description of symptoms which were not typical of common chronic nephritis, i.e., incidence only in adults (no children affected), absence of high blood pressure, xanthochromia of palms and soles (Tanchevs sign), early hypochromic anemia, absence of proteinuria, and slow progression of kidney failure.A striking feature of the disease is its very localized occurrence. There are approximately ten small areas where it occurs, all of them more or less rural, but nothing seems to connect those areas other than the occurrence of this illness. Tanchev and colleagues suggested that the condition was sui generis. Their initial tentative hypothesis for its cause was intoxication with heavy metals, because the affected villages were supplied with water coming from nearby Vratsa Mountain, a karst-type mountain.The disease was originally called "Vratsa nephritis," and became known as "Balkan endemic nephropathy" later, after people living in Yugoslavia and Romania were found to be suffering from it as well. But in Bulgaria and in neighbouring countries, the condition is known as "Tanchevs Nephropathy", in homage to Dr. Tanchevs work. See also
Nephropathy
Citrinin
Ochratoxin A

References


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