Background: The occurrence of anti-HLA de novo DSA (dnDSA) has been associated with the histological features of antibody-mediated rejection (ABMR) on kidney biopsy. The significance of early onset dnDSA as it relates to graft function has been largely unexplored. We sought to determine whether early onset dnDSA impacts graft function at 1 year, and to identify predictors of dnDSA development after alemtuzumab induction.

Methods: Kidney transplant recipients were prospectively screened for dnDSA from 7/1/2014 to 6/30/2016 at months 1-6, 9, 12, 18 and 24. Sera were tested by Luminex bead assay and levels >500 MFI were considered positive. Induction immunosuppression was with alemtuzumab and maintenance was with tacrolimus and mycophenalate mofetil. dnDSA was treated if MFI was >5,000 or ABMR was seen on biopsy.

Results: In total 129 consecutive transplant recipients were screened for dnDSA appearance. Mean age was 53 ± 14 yrs; 62% were Caucasian; mean BMI was 28 ± 6, and average time on dialysis was 42 ± 70 months. High BMI, African American ethnicity and longer time on dialysis pre-transplant were all identified as predictors of early appearance of dnDSA post-transplant.

Mean follow up period was 12 ± 6 months (3 – 24 months) and of these 94 completed 1 year. In this total cohort 27 developed class I dnDSA ( mean peak MFI = 3900); 27 class II dnDSA (mean peak MFI = 12 ,900) and 8 both (35% overall incidence). At the 1 year mark 61% of class I and 36 % of class II dnDSA's resolved spontaneously leaving a 12% prevalence of DSA at one year.

Mean eGFR at 1 year for dnDSA –ve recipients was 48.8 ± 2.7 ml/min vs 51.2 ± 5.2 ml/min for those with resolved dnDSA (p =0.44). Similarly, no significant differences in eGFR were detected at 1 year between DSA positive vs DSA negative recipients ( 52.4 vs 48.8 ml/min respectively).

Conclusions:

In this cohort, the overall incidence of early onset dnDSA was 35% and the majority resolved spontaneously. At the one year mark the eGFR in the DSA positive group was not significantly lower compared to the DSA negative group suggesting that these observations need to be extended for a longer time period. High BMI, African American ethnicity and longer time on dialysis pre-transplant were positive predictors of early appearance of dnDSA post-transplant.

CITATION INFORMATION: Abate M, Nigatu Y, Ryu B, Darras F, Jafrin R, Suh H, Estrada C, Nord E. Low Level Early Onset De Novo DSA's May Not Portend Early Graft Dysfunction in Kidney Transplant Recipients. Am J Transplant. 2017;17 (suppl 3).

« Back to 2017 American Transplant Congress