A 39-year-old man seeks care for his third episode of gross hematuria. His first episode occurred shortly after onset of an upper respiratory infection 2 years ago. His most recent episode started about 5 days ago. Both episodes lasted 5-10 days and were not associated with either flank or abdominal pain. The episodes had accompanying mild dysuria. There were no blood clots passed. He has no other medical problems. He takes no medication. There is no family history of kidney disease.
His blood pressure is 132/90 mm Hg, pulse is 72/min, and respirations are 12/min. Physical examination shows no significant abnormalities.
The patient's laboratory studies show:

Using phase-contrast microscopy, the pathologist finds several dysmorphic red blood cells in the urine. Which of the following is the most appropriate next step in management?

Question

A 39-year-old man seeks care for his third episode of gross hematuria.  His first episode occurred shortly after onset of an upper respiratory infection 2 years ago.  His most recent episode started about 5 days ago.  Both episodes lasted 5-10 days and were not associated with either flank or abdominal pain.  The episodes had accompanying mild dysuria.  There were no blood clots passed.  He has no other medical problems.  He takes no medication.  There is no family history of kidney disease.
His blood pressure is 132/90 mm Hg, pulse is 72/min, and respirations are 12/min.  Physical examination shows no significant abnormalities.
The patient's laboratory studies show:

Using phase-contrast microscopy, the pathologist finds several dysmorphic red blood cells in the urine.  Which of the following is the most appropriate next step in management?

Quizplus · Accepted Answer

The significant proteinuria and dysmorphic red blood cells on urinalysis establishes glomerular disease as the most likely cause of this patient's hematuria, and the clinical presentation is suggestive of IgA nephropathy. 11ec193a_98ef_74d0_853d_4fae69422c0d_MD0002_00 The table above summarizes the most common clinical presentations of IgA nephropathy, which is the most common cause of idiopathic glomerulonephritis in developed countries. Factors associated with an adverse prognosis include elevated blood pressure, lower than normal estimated glomerular filtration rate (GFR), and significant proteinuria. Thus, quantitative assessment of GFR and proteinuria to establish a baseline in this patient is the next step to predict future deterioration in renal function and therapeutic options. Renal biopsy is usually done to confirm the diagnosis in patients with protein excretion >500 mg/day, elevated serum creatinine (>1.5 mg/dL), and hypertension. (Choice A) Antibasement membrane antibody is found in patients with Goodpasture syndrome, a pulmonary-renal syndrome characterized by pulmonary hemorrhage and glomerulonephritis. Goodpasture syndrome is rarely associated with recurrent episodes of hematuria and usually causes significant pulmonary hemorrhage with markedly decreased GFR. (Choice B) Cystoscopy is indicated in the evaluation of hematuria if there is suspicion of bladder cancer. In this young patient, gross hematuria with proteinuria suggests a glomerular cause of hematuria, and cystoscopy is not indicated. (Choice C) Kidney CT scan is useful to evaluate for nephrolithiasis, chronic tubulointerstitial nephritis, or mass lesions (e.g., renal cell carcinoma). Because this patient's hematuria with proteinuria suggests a glomerular etiology, a renal CT scan would be less diagnostic. (Choice E) Urine cytology can be helpful in diagnosing cancers of the renal pelvis, ureter, and bladder. However, this patient's clinical presentation is less consistent with these diagnoses. Educational objective: The presence of significant proteinuria and dysmorphic red blood cells on urinalysis suggests a glomerular cause of hematuria. IgA nephropathy is characterized by recurrent episodes of gross hematuria (glomerulonephritis), typically following an upper respiratory infection. Factors associated with an adverse prognosis include elevated blood pressure, lower than normal estimated glomerular filtration rate, and significant proteinuria. __________ References: Remission of proteinuria improves prognosis in IgA nephropathy (http://www.ncbi.nlm.nih.gov/pubmed/17978307)

A 39-Year-Old Man Seeks Care for His Third Episode of Gross