Tubulointerstitial nephritis associated with acute intermittent porphyria.

Progressive renal impairment associated with acute intermittent porphyria is not well recognized and the mechanism of renal damage remains unclear. We report a case of a 51-year-old female with acute intermittent porphyria and long-term follow-up who developed proteinuria and renal insufficiency. Her biopsy showed marked tubulointerstitial damage with mitochondrial abnormalities. Urinary excretion of lipid peroxidation was increased compared to healthy controls. The porphyrin precursors may increase lipid peroxidation products and damage mitochondria leading to tubulointerstitial nephritis.