Insidious rifampin-associated renal failure with light-chain proteinuria.

A patient who was receiving rifampin treatment for tuberculosis developed heterogenous light-chain proteinuria and insidious renal failure after a period of fluid restriction. The renal damage was characterized pathologically by an interstitial nephritis with invasive tubular casts and an associated renal vein thrombosis. The possible role of the light-chain proteinuria in the pathogenesis of the renal failure is discussed.