Chapter 28: Immunoglobulin A Nephropathy and Henoch–Schönlein Purpura
A 45-year-old Asian female is found on routine employment physical to have microscopic hematuria with normal serum creatinine and no casts in the urine. She denies ever seeing blood in her urine and is not menopausal but is currently not menstruating. Her blood pressure is 130/85 and she only takes birth control pills. She is an occasional smoker. She is an avid runner, and runs about 5 miles a day.
How would you begin to work up the hematuria in this patient?
A. Do an in and out urinary catheterization to see if the blood is coming from the urinary tract.
B. Do a contrast CT of the urinary tract.
C. Order a renal ultrasound.
E. Do no further work-up.
The answer is C. The most likely diagnosis in IgA nephropathy. While the blood could be coming from the genital tract, this is unlikely. A CT contrast scan is more than is needed and it is too soon for a biopsy given normal renal function. Since she is a smoker, there are possible bladder lesions, and also possible kidney stones, so a renal ultrasound is the best screening test with the fewest possible complications. Although not listed here as one of the choices, a cystoscopy would be reasonable given concern for transitional cell cancer in setting of smoking, as well as trial of cessation of running and birth control pills since they can cause hematuria as well.
A healthy 25-year-old white man developed gross hematuria one day after upper respiratory tract infection. He denies abdominal pain, rashes, or use of illicit drugs. Blood pressure is 160/95, pulse 80. Physical examination is remarkable only for pharyngeal injection without any discharge and nasal congestion. Urinalysis confirmed gross hematuria and also revealed occasional red blood cell cast, many dysmorphic red blood cells, and 2+ proteinuria. Serum creatinine is 2.5 mg/dL.
What is the most appropriate next step in evaluating and treating this patient?
A. Quantify the proteinuria
C. High dose corticosteroid
E. Serum anti-streptolysin O levels
The answer is B. Given the presence of gross hematuria and acute kidney failure in the setting of “synpharyngitic hematuria” (hematuria occurring at the same time as upper respiratory tract infection, the most likely diagnosis is IgA nephropathy, with potential for crescentic presentation. ...