A case report of nephrotic syndrome associated with rifampicin therapy.

We describe nephrotic syndrome occurring in a 53-year-old male patient on continuous rifampicin (RFP) therapy for pulmonary tuberculosis. After the pulmonary tuberculosis was improved by chemotherapy that included RFP, administration of Isoniazid and RFP was continued. After 16 weeks, he suddenly developed nephrotic syndrome, but never developed acute renal failure. He was admitted to hospital and renal biopsy was performed revealing minor glomerular abnormalities and few interstitial changes in light microscopy. No positive immunofluorescent microscopic findings were obtained without fibrinogen. Thus, minimal change nephrotic syndrome (MCNS) was diagnosed. In contrast, electron microscopy showed several injurious glomerular changes, such as the elevation of the endothelial layer, local widening of the subendothelial space which was filled with fine granular or fibrillar materials, irregularity of the endothelial investment, swelling or shrinkage of the endothelial cells, compatible with those seen in many diseased conditions supposedly caused by clinical or subclinical localized intravascular coagulation. Discontinuation of RFP administration completely relieved the patient of MCNS with the aid of predonisolone therapy. Thus, this patient might not have been a case of incidental, but rather drug (RFP)-induced MCNS.