Q) I have been treating a 60-year-old man with a long history of microscopic hematuria and waxing/waning proteinuria. What could be the cause of his hematuria?
Hematuria is a consequence of erythrocytes, or red blood cells (RBCs), in the urine. This can cause a visible change in color, considered gross or macroscopic hematuria; or the blood may only be visible under microscopy or by urine dipstick (referred to as microscopic hematuria).
Both findings are followed up with urinalysis to quantify erythrocytes, protein, and presence of casts and to review RBC morphology. This information will assist in determining if the hematuria is glomerular or nonglomerular in origin.1
The examination and treatment plan for nonglomerular hematuria will focus on urinary tract diseases. If the patient is found to have glomerular hematuria, the focus will be on diseases of the kidney. A thorough history and physical should be performed in addition to urinalysis.
Glomerular disease is suggested in those with micro- or macroscopic proteinuria, proteinuria > 1 g/24h, or an absence of casts. Our index patient has microscopic hematuria and “waxing/waning” (unquantified) proteinuria, suggesting glomerular origin.
There are a number of renal causes for glomerular bleeding, including primary glomerulonephritis, multisystem autoimmune disease, and hereditary or infective glomerulonephritis.2 Renal biopsy is recommended for patients who have hypertension, proteinuria, and hematuria, to determine the cause and thus determine the appropriate treatment.
Amy L. Hazel, RN, MSN, CNP
Kidney & Hypertension Consultants, Canton, Ohio
REFERENCES
1. Greenberg A. Primer on Kidney Diseases. 5th ed. Philadelphia, PA: Elsevier Saunders; 2005.
2. Barratt J, Feehally J. IgA nephropathy [disease of the month]. J Am Soc Nephrol. 2005;16(7): 2088-2097.