A 62-year-old woman with a 10-year history of hypertension presented with elevated serum creatinine (2.26 mg/dL; reference range, 0.6-1.2 mg/dL). She had not visited a physician for several years but reported feeling well with no active symptoms. She had no risk factors for hepatitis B, hepatitis C, or HIV and reported no use of nonsteroidal anti-inflammatory drugs or herbal medications. One year ago, her urine was tea-colored during an upper respiratory tract infection. Examination results were normal except for elevated blood pressure (154/90 mm Hg). Although her hemoglobin concentration was low (10.5 g/dL; reference range, 11.6-15.2 g/dL), white blood cell count, platelet count, and electrolytes were normal. Her kidneys appeared structurally normal on ultrasound. Urine studies were performed (Table).
Harel Z, Simel DL, Wald R. Urinalysis in the Evaluation of Proliferative Glomerulonephritis. JAMA. 2017;318(13):1276–1277. doi:10.1001/jama.2017.14482