Inferior Kidney Allograft Outcomes in Patients With De Novo Donor-Specific Antibodies Are Due to Acute Rejection Episodes

Background. Donor-specific antibodies (DSAs) after kidney transplantation have been associated with poor graft outcomes in multiple studies. However, these studies have generally used stored sera or a single cross sectional screening test to identify patients with DSA. We evaluated the effectiveness of a prospective DSA screening protocol in identifying kidney and kidney/pancreas recipients at risk for poor graft outcomes. Methods. From September 2007 through September 2009, 244 consecutively transplanted kidney and kidney/pancreas recipients without pretransplant DSA were screened for de novo DSA at 1, 6, 12, and 24 months and when clinically indicated. Results. DSA was detected in 27% of all patients by protocol or indication screening. Patients with DSA (DSA+) were significantly more likely to have experienced acute rejection (AR) compared with no DSA (DSA-) (29% vs. 9.5%, P < 0.001), and lower estimated 2-year graft survival (83% vs. 98%, P < 0.001). Only 3 of 19 DSA (+) patients with AR had DSA detected before the AR episode. When excluding patients with AR, 2-year graft survival was similar between DSA (+) and DSA (-) patients (100% vs. 99%) as was estimated glomerular filtration rate. Patients with DSA detected by protocol screening had similar outcomes compared with DSA (-), whereas those with DSA detected by indication experienced significantly worse outcomes. Conclusions. Patients with de novo DSA experience worse graft outcomes due to previous/concurrent episodes of AR. A prospective DSA screening protocol failed to identify patients at risk for AR or poor short-term graft outcomes.