A case of Chinese herbs–induced renal interstitial fibrosis associated with fibrosis of salivary glands

We report a case with interstitial nephropathy induced by Chinese herbs that was accompanied by lesions in the minor salivery glands. A 61-year-old man had taken Chinese herbs since 1989 to “promote health.” Mouth dryness started around April 1996, and he was hospitalized in December because of kidney dysfunction. On admission, serum urea nitrogen was 20 mg/dL; serum creatinine, 2.5 mg/dL; serum uric acid, 2.5 mg/dL; serum phosphate, 1.6 mg/dL; and urinary β2-microglobulin, 67,468 μg/d. In addition, general aminoaciduria, renal glucosuria, and proximal tubular acidosis were noted, and he was diagnosed as having Fanconi syndrome. Kidney biopsy showed thickening and doubling of the glomerular basement membrane. Cell infiltration was scarce in the interstitium, with destruction of tubules and severe interstitial edema and fibrosis. Lip biopsy performed because of significant thirst showed atrophy and fibrosis of the minor salivary glands with poor cell infiltration. Most of the symptoms were improved after discontinuation of Chinese herbs. This case shows the possibility that Chinese herbs might have caused tissue damage characterized by fibrosis, not only in the kidneys, but also in the salivary glands.