Long-term post transplant alloantibody monitoring: a single center experience.

Between 2000 and 2010, 4241 sera from 597 renal transplant (RTx) recipients were monitored for DSA development. The patients were selected in the absence of immunological memory to donor HLA before RTx and were divided into two groups: the historic group, consisting of patients transplanted before December 1996 and the study group, consisting of those transplanted after December 1996. Ninety-two out of 597 (15.4%) patients developed de novo DSA post-RTx, while 196 had third party anti-HLA antibodies. DSA were more frequent in the historic group compared with the study group (P < 0.001). Anti-HLA class-III DSA predominated in both groups (84.6% vs. 69.7%) and were directed preferentially against donor HLA-DQ (65/92,70.6%). Recipients of class II-incompatible grafts developed DSA more frequently than those receiving class II-compatible grafts (P = 0.003). DSA production was not different between pre-sensitized and non-sensitized patients (P = 0.842). DSA class I (HR = 31.78), DSA class II (HR = 20.92), and non-DSA (HR = 5.94) were the only independent predictors for graft failure. In conclusion, this study shows the results of long-term post-transplant alloantibody monitoring, and confirm the strong association of DSA and graft loss. Protocols that remove anti-HLA antibodies from RTx recipients may benefit allograft survival.