77.05 HLA-DR13 and -DR15 Are Associated with Short-term Rejection in Lung Transplantation

T. W. Liang¹, A. S. Gracon¹, K. Rothhaar¹, J. Wu¹, D. S. Wilkes^{1,2 1}Indiana University School Of Medicine,Indianapolis, IN, USA ²University Of Virginia,Charlottesville, VA, USA

Introduction:
Lung transplantation outcomes are among the least favorable, with the majority of recipients eventually developing bronchiolitis obliterans syndrome (BOS) and subsequent graft failure. Human leukocyte antigen (HLA)-DR15 has been implicated in the pathogenesis of BOS. Presence of this and other HLA-DR antigens may play a role in these poor outcomes. The objective was to identify the effects of having these antigens on patient outcome.

Methods:
Lung transplant donor and recipient data were retrospectively gathered from the United Network for Organ Sharing (UNOS) database from January 2006 to June 2013. Donor and recipient characteristics, proportion of recipients treated for rejection within the 1^st year of transplant, 5-year survival rate, and 5-year rate of freedom from BOS were determined according to HLA-DR1, -DR7, -DR13, and -DR15 status in both the donor and recipient. Each HLA-DR allele was stratified by donor and recipient pair status – donor- and recipient-positive (D⁺R⁺); donor-positive but recipient-negative (D⁺R^–); donor-negative but recipient-positive (D^–R⁺); and donor- and recipient-negative (D^–R^–) for a particular allele.

Results:
8161 lung transplant recipients were analyzed. There were significant but small differences in donor and recipient characteristics for each HLA-DR group. The recipients in the D^–R⁺ pairing for HLA-DR13 and those in the D⁺R^– pairing for HLA-DR15 had significantly higher rates of receiving treatment for rejection within the 1^st year after transplant (p=0.024 and p=0.001, respectively). There were no differences in 5-year survival or freedom from BOS for any of the four HLA-DR alleles that were studied.

Conclusion:
There are higher rates of patients treated for rejection within the 1^st year who are either negative for the HLA-DR15 allele but received a donor-positive lung or positive for the HLA-DR13 allele but received a donor-negative lung for that allele. However, these differences do not appear to affect long-term survival and freedom from BOS.