Impact of Pre-Transplant Immunosuppression in CT-ILD Recipients

Abstract

<h3>Purpose</h3> The use of immunosuppressive biologic agents (BA) in CT-ILD patients has increased. These agents have long half-lives and a high infection risk leading to our hypothesis that these patients will have more infectious complications. This study compares early outcomes in patients who received pre-transplant traditional immunosuppression (MMF, AZA, hydroxychloroquine, cyclophosphamide) (TI), pre-transplant BA (anti-CD20, TNF blockers, IL-6 inhibitors, JAK inhibitors) or no immunosuppression (IS). <h3>Methods</h3> Patients transplanted for ILD between 2/2008-4/2021 were retrospectively divided into 3 groups (grp): (1) TI, (2) BA, and (3) none. Maintenance IS included a calcineurin inhibitor, MMF/AZA, and prednisone. Targeted induction therapy with basiliximab occurred in patients with acute kidney injury post-transplant. Variables examined included baseline characteristics, infection within 6 mo, time to infection, and 1-yr survival. <h3>Results</h3> 161 pts were included in the analysis. 45 received TI, 13 received BA, and 103 received neither. Grps were comparable in age and induction therapy, but more males were present in each grp (p=0.001). Incidence of infection within 6 mo was higher in the TI grp compared to no IS grp (71% vs 46%, p=0.004). Time to initial infection was shorter in the TI grp (86 vs 119 vs 121 d) when compared to the BA and no IS cohorts (p=0.016). There was no difference in length of initial hospital stay or 1-yr survival. <h3>Conclusion</h3> Our single-center experience demonstrates that the utilization of traditional therapeutic immunosuppressive agents when compared to BA or no IS to treat CT-ILD prior to transplantation results in a greater risk of early infection but does not impact survival. Transplantation of patients receiving newer BA does not appear to increase early infection rates, but this may be due to selection bias or low numbers in this analysis. Discontinuing TI well ahead of the transplant may have a protective effect in preventing early post-transplant infection.