Chyluria presenting as milky urine and nephrotic-range proteinuria

CASE PRESENTATION A 41-year-old woman was admitted to Harlem Hospital Center for the evaluation of nephrotic-range proteinuria, microhematuria, hypoalbuminemia, and edema. The patient was born in the Dominican Republic and came to the United States 10 years ago. She gave a history of episodic cloudy urine for the past 28 years. Five years before admission during her last pregnancy, she was noted to have proteinuria (2 g/24 h). Two years before admission, she was treated for filariasis at another hospital, and after 1 year, she was admitted to the same hospital for edema and was found to have chronic active hepatitis C infection with incipient cirrhosis by liver biopsy. For the past 3 months, the patient noted progressive swelling of both lower extremities associated with episodic passage of cloudy urine and flank pain. There was no history of diabetes mellitus, hypertension, renal stones, or gross hematuria. She was on no medications and denied alcohol, illicit drug, and tobacco use. Physical examination revealed a thin and malnourished woman weighing 55.5 kg with a temperature of 371C, pulse 92/min, and blood pressure 104/60 mmHg. There was no skin rash. The heart and lung examinations were normal. The abdomen was soft with the liver palpable 3 cm below the right costal margin. The spleen was not palpable and there was no shifting dullness. There was 3þ pitting bilateral pedal edema. Laboratory data on the current admission included hematocrit 46% (reference interval, 42–52%), white blood count 6.6 10/l (reference interval, 4.0–10.5 10/l) with normal differential, platelet count 381 10/l (reference interval, 150–500 10/l), blood urea nitrogen 7 mg/dl (2.5 mmol/l) (reference interval, 7–18 mg/dl, 2.5–6.4 mmol/l), serum creatinine 0.7 mg/dl (63 lmol/l), total protein 4.1 g/ dl (41 g/l) (reference interval 6.0–7.8 g/dl, 60–78 g/l), albumin 1.9 g/dl (19 g/l) (reference interval 3.5–5.0 g/ dl,35–50 g/l), bilirubin 0.5 mg/dl (8.6 lmol/l) (reference interval 0.2–1.0 mg/dl, 3.4–17.1mmol/l), aspartate aminotransferase 100 U/l (reference interval 10–40 U/l), ala nine aminotransferase 38 U/l (reference interval, 10–35 U/ l), alkaline phosphatase 408 U/l (reference interval, 20–80 U/ l), serum cholesterol 208 mg/dl (5.38 mmol/l) (recommended o200 mg/dl, o5.18 mmol/l), and triglyceride 108 mg/dl (1.22 mmol/l) (recommended 35–135 mg/dl, 0.40–1.52 mmol/l). Serologic work-up showed positive hepatitis C antibody and positive hepatitis B core antibody. Serologic tests for hepatitis B surface antigen, hepatitis B surface antibody, syphilis, human immunodeficiency virus, antinuclear antibody, and cryoglobulin were negative. The serum complement levels including C3, C4, and CH50 were within the normal ranges. Five days before admission, a routine urinalysis was reported as showing clear yellow urine with 2þ protein, 4þ blood, and negative leukocyte esterase. A follow-up urinalysis on the day of admission, however, showed milky urine with clots, 4þ protein, and 3þ blood. Microscopic examination of the urine sediment showed many red blood cells and a few epithelial cells per high-power field. There were no oval fat bodies, fatty casts, cellular casts, or crystals. Examination of stained urine sediment by modified Wright stain (Hansel’s stain) revealed many isomorphic red blood cells and lymphocytes (Figure 1). Addition of Sudan III to an aliquot of this milky urine, followed by mixing and shaking with an equal volume of chloroform and centrifugation, produced clearing of the cloudy urine with the appearance of stained fatty globules in the organic layer (Figure 2). A 24-h urine collection yielded 6.5 g of protein and a creatinine clearance of 91 ml/min. A urine protein electrophoresis showed non-selective proteinuria. A chest X-ray and an electrocardiogram were normal. An abdominal ultrasound showed a 14 cm liver with increased echotexture; the kidneys were normal in size and echotexture. Differential diagnosis of the renal abnormalities included nephrotic syndrome owing to hepatitis C-associated membranous or membranoproliferative glomerulonephritis, minimal change disease, and chyluria. A renal biopsy was performed. t h e r e n a l c o n s u l t http://www.kidney-international.org