Rapidly progressive fibrosing interstitial nephritis associated with Chinese herbal drugs.

Rapidly progressive fibrosing interstitial nephritis after a slimming regimen containing aristolochic acid has been identified as Chinese herbs nephropathy (CHNP). From 1995 to 1998, we observed 12 Chinese people from different areas of Taiwan who underwent renal biopsy for unexplained renal failure. Medical history gave no clue to the causes of impaired renal function except for the ingestion of traditional Chinese herbs. Although these patients ingested herbal drugs from various sources for different purposes, their renal biopsy samples showed amazingly similar histological findings, with extensive hypocellular interstitial fibrosis and atrophy and loss of tubules in all cases. Glomeruli were apparently intact. They also had similar clinical features, such as normal or mildly elevated blood pressure, early and severe anemia, low-grade proteinuria, glycosuria, and insignificant urinary sediments. Renal function deteriorated rapidly in most patients despite discontinuation of the herbal medicines. Seven patients underwent dialysis, and the remainder experienced slowly progressive renal failure. Bladder carcinoma was found in one patient. Morphologically and clinically, the nephropathy in our patients was similar to CHNP, reported in Belgium. Because of the complexity and unknown types of herbs used in different clinical situations, unidentified phytotoxins other than aristolochic acid might be responsible for this unique disease entity. We conclude that the relation of this nephropathy to the consumption of Chinese herbs is striking. Using uncontrolled herbal remedies carries a high risk for developing interstitial renal fibrosis and urothelial malignancy.