Background: Donor specific anti-human leukocyte antigen (HLA) antibodies (DSA) after renal transplant have been associated with poor outcomes in the form of renal dysfunction, increased rejection rates, and graft failure. The purpose of our study was to identify patients at risk for de novo DSA through prospective surveillance in a large cohort of ethnically diverse patients.

Methods: We prospectively assessed 608 kidney transplant recipients from 7/2007-7/2011. Of these 103 were excluded for pre-transplant DSA, 0-HLA mismatch, incomplete HLA typing, and follow-up less than 1 month. DSA were monitored at months 1, 3, 6, 9, and 12 post-transplant along with every 6 months thereafter. Recipients with graft dysfunction and concern for rejection were also tested.

Results: The analysis included 505 recipients; of these, 42% were Caucasian, 28% African American (AA), and 24% Hispanic. At a median of 6.1 months, 121 (24.0%) recipients developed a de novo DSA. Of those with DSA, 42 had antibodies (or DSAs) directed towards a class I antigen, 105 towards class II, and 26 towards both. The majority of DSA were directed against DQ (n=88). Table 1 lists differences found by univariate analyses between those with and without DSA. No differences were detected in recipient age or gender, re-transplant, PRA >20%, or donor age or gender.

After multivariate analysis, AA race, kidney-pancreas transplant, and degree of HLA mismatch remained independent risk factors (Table 2). For every 1 antigen mismatch, there was a 22% increased risk of de novo DSA development.

Conclusions: Prospective DSA monitoring in a large cohort of patients, of whom more than half were non-Caucasian, identified a de novo DSA rate of 25%. AAs, kidney-pancreas recipients, and those with a higher rate of HLA mismatch were at a higher risk for de novo DSA development. Increased DSA monitoring may be warranted in recipients with independent risk factors for de novo DSA.

« Back to 2013 American Transplant Congress