Patient 1. A 34-year-old black man presented to the Emergency Room of Columbia-Presbyterian Medical Center complaining of weakness, an-orexia, and nausea of several weeks duration, and edema of the legs for 2 days. In the Emergency Room, his BUN was 80 mg/dl and the serum creatinine was 16.3 mgldl; he was admitted for further evaluation. The medical history was notable for an 8-year history of hypertension, treated only for 4 months with a diuretic. A" kidney infection" was treated 2 years prior to admission with oral antibiotics. There was no known history of diabetes, sickle-cell disease, or nephrolithiasis. His sister had recurrent" kidney infections" and his father died at age 70 from renal failure. The patient worked full-time as a taxi driver and youth counselor. He used nasal cocaine, but denied intravenous drug use or homosexual contacts.

The admission physical examination revealed: blood pressure 150—170/110—120 mm Hg, grade-i hypertensive retinopathy, a grade Il/VI systolic ejection murmur, scrotal and penile edema, a penile discharge, and 2+ edema of the lower extremities. Laboratory data included: hematocrit, 35.5%; white blood cell count, 8900 mm3; erythrocyte sedimentation rate, 123 mm/hr; serum creatinine, 16 ing/dI; and BUN, 80 mg/dl. Urinalysis revealed: 3+ protein; 20—25 white blood cells and 0—1 red blood cells/high-power field; and no casts. Serum albumin was 1.2 gIdl; total protein, 4.7 g/dl; and cholesterol, 390 mg/dl. A renal ultrasound examination disclosed hyperechoic kidneys. On nephrotomography, the left kidney measured 12 cm and the right, 11 cm. A 24-hour urine collection contained 36.5 g of protein, and the creatinine clearance was 5 cc/mm. Titers for antinuclear antibodies; latex fixation; cryoglobulins; hepatitis B surface antigen and antibody; and serum complement all were negative or normal. Tests for syphilis (Veneral Disease Research Laboratory, VDRL, test and fluorescent treponemal antibody, FTA test) were positive, and a urethral culture grew gonococcus; HIV serologies were obtained. The patient was treated with procaine penicillin for acute gonorrhea and