Special Feature American Society of Nephrology Clinical Pathological Conference

A 13-year-old girl presented with proteinuria and acute kidney failure. She was born at full term via cesarean delivery (due to nuchal cord), but there were no other prenatal or perinatal complications. In early childhood the patient had two hospitalizations at ages 4.5 and 9 years, respectively, the latter for pneumonia. She had no history of symptoms of kidney disease. She came to the hospital at age 12 years for routine bilateral molar extractions. She was treated with oral antibiotics and discharged after the procedure without complications. At age 13 years, 10 months after the molar extraction, she was seen by a pediatrician because of puffiness and increased BP. She had had respiratory symptoms 2 weeks before presentation. The pediatrician prescribed furosemide and amlodipine. A few days later, the patient returned to the pediatrician’s office because of hand, ankle, and facial swelling and malaise. The pediatrician recommended hospitalization and the patient was admitted at this time. Clin J Am Soc Nephrol 9: 818–828, 2014. doi: 10.2215/CJN.12481213 Introduction A 13-year-old girl presented with proteinuria and acute kidney failure. She was born at full term via cesarean delivery (due to nuchal cord), but there were no other prenatal or perinatal complications. In early childhood, the patient had two hospitalizations at ages 4.5 and 9 years, respectively, the latter for pneumonia. She had no history of symptoms of kidney disease. She came to the hospital at age 12 years for routine bilateral molar extractions. She was treated with oral antibiotics and discharged after the procedure without complications. At age 13 years, 10 months after the molar extraction, she was seen by a pediatrician because of puffiness and increased BP. She had had respiratory symptoms 2 weeks before presentation. The pediatrician prescribed furosemide and amlodipine. A few days later she returned to the pediatrician’s office because of hand, ankle, and facial swelling and malaise. The pediatrician recommended hospitalization and the patient was admitted at this time. The patient reported no recent infections, including pharyngitis and skin infection. She had no family history of renal disease, although a sibling has type 1 diabetes, and no personal history of hematuria or proteinuria noted previously. Physical examination revealed a well developed, well-nourished female. On admission, her temperature was 36.8°C, heart rate of 84 beats/min, respiratory rate of 14 breaths/min, and BP of 128/84 mmHg. Her weight was 61.4 kg (25th percentile), and her height was 149 cm (25th percentile). She had erythema of the oropharynx, but no exudate. Auscultation revealed decreased breath sounds at the lung bases. Cardiac examination showed regular rate and rhythm without murmur or S4. The abdomen was soft, with no fluid detected. Extremities were remarkable for 2–3+ pretibial pitting edema to the knee. Her urinalysis revealed 3+ protein, 4+ blood, and 2+ leukocyte esterase but was negative for glucose, bilirubin, nitrite, and ketones. Urine specific gravity was 1.030 with a pH of 5.0. Microscopic examination revealed 21–50 red blood cells/high-power field (hpf), 21–50 white blood cells/hpf, 2+ bacteria, ,5 epithelial cells/hpf, and 1–5 hyaline casts; no cellular casts were seen. Initial laboratory studies are summarized in Table 1. The first eGFR, calculated using the Schwartz equation (1), was 102 ml/min per 1.73 m2. Chest radiography revealed a small bilateral pleural effusion but no focal or diffuse parenchymal infiltrates. The patient was restarted on diuretic therapy with 30 mg of furosemide given intravenously twice daily, and she was prescribed a low-sodium diet; normal BP was maintained with 5 mg amlodipine per day. During her hospitalization, her creatinine rose to 1.5 mg/dl and her BUN to 37 mg/dl. By day 4 after admission, the patient was hypertensive, necessitating an increase of amlodipine to 10 mg/d. Her creatinine increased to 2.5 mg/dl, her white blood cell count rose to 10,000 cells/ml, and her temperature increased to 38.4°C. Blood and urine cultures were performed. Systolic BP continued to rise to .140 mmHg, and creatinine peaked at 3.3 mg/dl. A kidney biopsy was performed, which was well tolerated, and the patient was followed in the outpatient setting pending the results. Clinical Discussant: Dr. Kevin E. Meyers In summary, this 13-year-old girl presented with nephritic-nephrotic syndrome and a fairly rapid rise in the serum creatinine concentration. Two to three weeks before clinical presentation, she had an upper *The Children