Antithymocyte Globulin is Associated with a Lower Incidence of De Novo Donor-Specific Antibody Detection in Lung Transplant Recipients: A Single-Center Experience

Abstract

De novo donor-specific anti-HLA antibodies (DSA) have been associated with significantly increased risk for antibody-mediated rejection (AMR) and lung allograft dysfunction. Induction immunosuppression has improved the long-term outcome of lung transplantation. However, the impact of Induction immunosuppression on the development of de novo DSA in lung transplant recipients is not well defined METHODS: We assessed the relationship between using rabbit Antithymocyte Globulin (rATG) for induction immunosuppression and the development of de novo DSA in a cohort of consecutive lung transplant recipients (n = 67) that were followed for 12 months post-transplant. All recipients had negative flow cytometry crossmatch on the day of transplant. Anti-HLA antibodies in the serum were assessed at 1, 3, 6, 12 months post-transplant. DSA were defined as having a Mean Fluorescence Intensity (MFI) > 1000 RESULTS: 41/67 lung transplant recipients (LTR) received a single dose rATG (1.5 mg/kg) within 24 hours of transplant. De novo DSA were detected in 10/41 (24.3%) compared to 13/26 (50%) ATG and no ATG groups respectively at 12 months post-transplant. However, de novo DSA were detected within 1 month post-transplant in 5/10 (50%) compared to 3/13 (23.3%) rATG and no rATG groups respectively. There was no significant difference in the de novo DSA MFI levels between the rATG group (median MFI = 1379 & 2124 for class I & II respectively) compared to the no rATG group (median MFI = 2186 & 2388 for class I & II respectively) at 12 months post-transplant. De novo DSA prevalence is shown in Table 1. Induction with a single dose of rATG is associated with a significant decrease in the prevalence of HLA de novo DSA in LTR at 12 months post-transplant. De novo DSA were detected earlier in the rATG group compared to no rATG group. These findings warrant investigating in a larger study the impact of rATG induction on de novo DSA levels and lung allograft dysfunction.