Persistent, Asymptomatic, Microscopic Hematuria in Prospective Kidney Donors

BACKGROUND: Asymptomatic, microscopic hematuria is seen in 8-21% of the general population, has a good prognosis, and is generally not an indication for kidney biopsy. But whether it should preclude kidney donation is unclear. METHODS: Of 512 consecutive prospective donors, 14 (2.7%) continued to have asymptomatic, microscopic hematuria over 1 month. If the medical history, physical examination, and computerized tomographic angiography were unremarkable, and if they still wished to donate, a kidney biopsy was performed. RESULTS: In two prospective donors, hematuria resolved after treatment for urinary tract infection; two others declined donation and were referred to their primary care provider. Kidney biopsy in the remaining 10 showed: two normal; four thin basement membrane nephropathy (TBMN); one nonhomogeneous basement membrane abnormalities; one IgA nephropathy, 5 of 16 glomeruli globally sclerotic; one in a patient with a family history of Schimke's Syndrome, 7 of 30 glomeruli globally sclerotic; and one TBMN and early hypertensive changes without systemic hypertension. Only 4 of the 10 who underwent kidney biopsy donated (two normal, two TBMN). CONCLUSIONS: Kidney abnormalities are common in young, otherwise healthy, prospective kidney donor candidates with persistent, asymptomatic, microscopic hematuria. A kidney biopsy is often abnormal and aids in the decision-making process.