A 29-year-old male with HIV, on indinavir, zidovudine, and stavudine, presents with severe edema and a serum creatinine of 2.0 mg/dL. He has had bone pain for 5 years and takes large amounts of acetaminophen with codeine, aspirin, and ibuprofen. He is on prophylactic trimethoprim sulfamethoxazole. Blood pressure is 170/110; urinalysis shows 4+ protein, 5 to 10 RBC; 24-h urine protein is 6.2 g. What is the most likely cause of his renal disease?

Although many glomerular lesions occur in association with HIV, focal sclerosis is by far the commonest etiology of this patient's syndrome. While focal sclerosis is more common in intravenous drug users than homosexuals, the lesion is different than so-called heroin nephropathy. Indinavir toxicity may cause tubular obstruction by crystals and is a cause of renal stones, but does not cause nephrotic syndrome. Analgesic nephropathy is a frequently unrecognized cause of occult renal failure; this entity requires at least 10 years of analgesic use and rarely causes significant proteinuria. Trimethoprimsulfamethoxazole may cause acute interstitial nephritis, but there is no fever, rash, WBC casts, or eosinophils in the urinalysis.