Rabbit Anti-thymocyte Globulin Induction Therapy Does Not Prolong Survival After Lung Transplantation

Abstract

Lung transplant survival is limited by the development of bronchiolitis obliterans syndrome (BOS). The strongest risk factor for BOS is acute rejection (AR). We have previously shown that rabbit anti-thymocyte globulin (RATG) induction therapy is associated with a decrease in early AR. Thus, we hypothesized that RATG induction would translate to reduced BOS and improved long-term graft survival. Forty-four lung recipients were prospectively randomized to receive conventional immunosuppression with RATG induction (RATG group) or conventional immunosuppression alone (control group). End-points included graft survival, early and total acute rejection, BOS and treatment complications. There was no difference in graft survival between the groups at 8 years (RATG: 36%; control: 23%; p = 0.48). The RATG group had fewer early rejections compared with the control group (5% vs 41%; p = 0.01). However, the overall rejection incidence did not differ (RATG: 62%; control: 68%; p = 0.52). There was a trend toward a delay in BOS onset among RATG subjects compared with control subjects (2,376 days vs 1,108 days; log rank, p = 0.15). There was no difference in the incidence of infections, but the RATG group had a higher rate of malignancies. Our results suggest that alternative approaches to anti-thymocyte induction should be pursued to reduce BOS and prolong allograft survival.