Donors at risk: proteinuria

• Potential living donors should have their urinary protein excretion measured using either a 24-hour urine collection (daily excretion) or a spot urine sample (protein/creatinine ratio). • A urine protein excretion of >300 mg/day (24 hour collection) or of >30 mg/mmol (spot urine protein/ creatinine ratio) is usually a contraindication to live donation. • Further investigations are warranted when urine protein excretion is >150 mg/day but less than <300 mg/ day (corresponds approximately with spot urinary protein/ creatinine of >15 mg/mmol but <30 mg/mmol). Repeat urinary protein estimation, as well as measurement of urinary albumin excretion may help in further assessing potential living donors. • Although overt proteinuria may be absent, the presence of microalbuminuria (urinary albumin excretion of >30 mg/day or >20 mg/min; albumin/creatinine ratio >2.5 mg/mmol) should be considered a relative contraindication to live donation. • Microalbuminuria or mild proteinuria (<300 mg/day) occurring in the presence of another associated clinical or laboratory abnormality (e.g. hypertension, obesity, glucose intolerance, glomerular haematuria) should be considered a relative contraindication to live donation. • In potential living donors with minor degrees of proteinuria or albuminuria, a renal biopsy may help in further assessing the donor’s risk of developing progressive renal disease following donation (Opinion). • Donors should have their urinary protein excretion measured as part of their routine, follow-up care. It is recommended that this be performed at least once a year along with blood pressure and serum creatinine measurement (Opinion).