Race, relationship and renal diagnoses after living kidney donation

Background. In response to recent studies, a better understanding of the risks of renal complications among African American and biologically related living kidney donors is needed. Methods. We examined a database linking U.S. registry identifiers for living kidney donors (1987-2007) to billing claims from a private health insurer (2000-2007 claims) to identify renal condition diagnoses categorized by International Classification of Diseases 9th Revision coding. Cox regression with left and right censoring was used to estimate cumulative incidence of diagnoses after donation and associations (adjusted hazards ratios, aHR) with donor traits. Results. Among 4650 living donors, 13.1% were African American and 76.3% were white; 76.1% were firstdegree relatives of their recipient. By 7 years post-donation, after adjustment for age and sex, greater proportions of African American compared with white donors had renal condition diagnoses: chronic kidney disease (12.6% vs 5.6%; aHR, 2.32; 95% confidence interval [95% CI], 1.48-3.62), proteinuria (5.7% vs 2.6%; aHR, 2.27; 95% CI, 1.32-3.89), nephrotic syndrome (1.3% vs 0.1%; aHR, 15.7; 95% CI, 2.97-83.0), and any renal condition (14.9% vs 9.0%; aHR, 1.72; 95% CI, 1.23-2.41). Although first-degree biological relationship to the recipient was not associated with renal risk, associations of African American race persisted for these conditions and included unspecified renal failure and reported disorders of kidney dysfunction after adjustment for biological donor-recipient relationship. Conclusions. African Americans more commonly develop renal conditions after living kidney donation, independent of donor-recipient relationship. Continued research is needed to improve risk stratification for renal outcomes among African American living donors.