Evaluation of proteinuria in healthy living kidney donor candidates.

BACKGROUND: Evaluation of living kidney donor candidates includes careful assessment for the presence or absence of kidney disease. Kidney donation has been considered to be at least relatively contraindicated if urinary total protein excretion is above the normal range. However, at the present time, there is no uniformly accepted level of urine total protein excretion that would exclude donation. Albumin excretion instead of total protein excretion as a criterion has not previously been evaluated. MATERIALS AND METHODS: This was a prospective observational study over a 3-year period in a single tertiary care center designed to assess current selection criteria for kidney donation with respect to urine total protein and albumin excretion. RESULTS: Twenty four percent (25 of 105) of healthy adult kidney donor candidates had elevated urinary total protein excretion rates (150 to 292 mg/24 h). Of these 105 candidates, 39 had simultaneous measurements of both urinary total protein and albumin. Although one-third (13/39) had elevated 24-hour urine total protein values, none had elevated urine albumin excretion. CONCLUSION: Measurement of albumin, the most common single protein found in urine, appears to be helpful in the evaluation of proteinuria in donor candidates. Many healthy adult kidney donor candidates have mildly elevated total protein excretion but normal albumin excretion. We believe that such patients should not be excluded from donation.