Sources of exposure:
(1) as a Chinese herbal medicine
(2) as a local herbal therapy in various countries
(3) contamination of wheat and other crops
Risk factors for the nephropathy includes:
(1) dose
(2) duration of the exposure
(3) genetic susceptibility
(4) living in a household with one or more affected people (presumably reflecting a common exposure)
Aristolocic acid produces a chronic tubulointerstitial nephropathy which shows a gradual progression towards end-stage renal disease. There is proximal tubule dysfunction with urinary excretion of beta-2-microglobulin and alpha-1-microglobulin.
Renal biopsy shows:
(1) hypocellular interstitial fibrosis
(2) tubular atrophy
(3) variable chronic inflammation of the interstitial tissue
(4) periglomerular fibrosis
(5) glomerular lesions
(6) arteriolar hyalinosis and intimal fibrous hyperplasia
The diagnosis requires exclusion of other causes of interstitial fibrosis (cadmium, lead, cyclosporin A, lithium, nitrosurea, ifosfamide, pamidronate, etc).
