Long-term outcomes of kidney donors with fibromuscular dysplasia

Background: Fibromuscular dysplasia (FMD) is a non-atherosclerotic systemic arterial disease that is not infrequently discovered during kidney donor evaluation. Current guidelines do not provide recommendations regarding the use of kidneys from donors with FMD and there is a paucity of data on the outcomes of these donors. Methods: The Renal and Lung Living Donor Evaluation (RELIVE) study addressed long-term outcomes of 8922 kidney donors who donated between 1963 and 2007. We compared the development of hypertension, cardiovascular disease (CVD), proteinuria and reduced estimated glomerular filtration rate (eGFR) in 113 kidney donors with FMD discovered during donor evaluation versus 452 propensity score matched donors without FMD. Outcomes modeling with logistic and Cox regression analysis and Kaplan-Meier statistics were performed. Results: Donors with FMD were older (51 versus 39 years), were more likely to be women (80% versus 56%) and had a higher systolic blood pressure at donation (124.7 versus 121.3 mmHg) (P < 0.05 for all). After a mean ± standard deviation follow-up of 15.5 ± 8.9 years, a similar proportion of donors with and without FMD were alive, and developed hypertension (22.2% versus 19.8%), proteinuria (20.6% versus 13.7%) and CVD (13.3% versus 13.5%). No donor with FMD developed an eGFR <30 mL/min/1.73 m2 or end-stage kidney disease. The multivariable risk of mortality, CVD and renal outcomes in donors with FMD was not elevated. Conclusions: Kidney donors with FMD appear to do well, do not appear to incur increased risks of hypertension, proteinuria, CVD or reduced eGFR, and perhaps carefully selected candidates with FMD can safely donate as long as involvement of other vascular beds is ruled out.