Background: Antibody mediated rejection (ABMR) can occur through pre-transplant(tx) vs. de novo donor specific antibodies (DSA). Clinical outcomes, allograft injury and dynamics of DSAs have not been compared between 2 groups in a large cohort of patients.Methods: This is a prospective study including 687 patients who received a kidney between 1/2009 and 12/2014 at our center. Protocol testing for DSA was done before and at 1, 3, 12 months, and then annually after tx or when clinically indicated. The cutoff value for DSA MFI was 1000. Patients with preformed DSAs received a transplant with ATG and IVIG induction treatment if CDC cross-match was negative and MFI value was < 5,000 for HLA-A, B, DR and < 10,000 for HLA-C, DQ and DP.Results: 108 (16%) patients had pre-tx DSA before transplantation. During a median 3.8 (2.4-5.3) yrs of follow-up, de novo DSA developed in 95 patients (17 %) at a median of 1.24(0.71-2.35) yrs after tx. There was no difference in demographics except that the pre-tx DSA group has lesser percentage of male (39% vs. 66%, p<0.001), received more anti-thymocyte globulin for induction (94.7% vs.58.5 %, p<0.001), and have higher PRA class I (52±37.6 vs. 14.5±24.4, P<0.001) and Class II (49.6± 35.3 VS. 17.8± 27.3, P<0.001) respectively. While there was no significant difference in patient survival, de novo DSA group had significantly lower graft survival (63.8% vs. 88.6%, P<0.001), higher ABMR rate (27.7% vs. 11.4%) and T cell mediated rejection (14.1 vs. 4.3%). ABMR developed at a median 0.39 yrs (0.13-1.4) in pre-tx DSA patients and at 1.25 yrs (0.25-3.31) in de novo DSA patients. There was no statistical difference in terms of acute and chronic Banff allograft injury scores between the two groups. 108 patients with pre-tx DSA, 67 patients lost DSA and 41 showed persistent DSA at one year post-tx. After the onset of serum denovo DSA positivity in 95 patients, 43% of DSA persisted, 33% of DSA were transient (DSA positivity on only one sample), 9 % of DSA MFI decreased by 50%. Of the 43 patients with denovo DSA who developed acute rejection, 7 had de novo DSA prior to rejection, 15 developed after rejection, and 21 did so concurrently.Conclusions: Denovo DSA after tx are associated with significantly higher ABMR rate and lower allograft survival when compared to low level pre-tx DSA. However, acute and chronic Banff allograft injury scores of ABMR were not different between the two groups.

CITATION INFORMATION: Ajaimy M., Hayde N., Colovai A., Akalin E. Pre-Transplant versus De Novo Donor Specific Antibodies: Differences in Clinical Outcomes and Antibody Mediated Rejection Am J Transplant. 2017;17 (suppl 3).

« Back to 2018 American Transplant Congress