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

Purpose 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. Conclusion 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.