Histologic Phenotypes and Outcomes in Single vs Double Lung Transplantation among Recipients with Interstitial Lung Disease

Abstract

<h3>Purpose</h3> The role of single vs double lung transplantation for ILD remains controversial due to heterogeneity within this population. This study elucidates the role of explant histology on outcomes among patients undergoing a single vs double lung transplant. <h3>Methods</h3> A total of 412 patients with ILD transplanted from 2001-2019 at our institution were retrospectively reviewed. Patients were stratified by those who underwent a single (n=239, 58%) or double (n=173, 42%) lung transplant. Explant pathology reports were analyzed to understand the effect of histologic phenotypes and post-transplant outcomes. Primary outcomes of interest included overall and CLAD free survival. Treatment effects were obtained using a multivariable Cox-proportional hazards function. <h3>Results</h3> Of the total population, 41.7% had UIP, 26.5% NSIP, 5.8% mixed NSIP+UIP, 14.8% hypersensitivity pneumonitis (HP), and 11.2% sarcoid on explant pathology. Overall survival was similar between histologic phenotypes. HP and NSIP had earlier development of CLAD compared to sarcoidosis and UIP. A single lung transplant was an independent predictor of mortality among recipients with HP at explant pathology on multivariable analysis. Single lung transplant was also an independent predictor for CLAD among patients with NSIP and HP. The rest of the histologic phenotypes UIP, mixed NSIP+UIP ad sarcoid failed to show a significant difference in any of the outcomes by the use of single vs double lung transplant. <h3>Conclusion</h3> Patients with ILD have distinct pathologic characteristics and related post lung transplant outcomes. Recipients with UIP, mixed NSIP+UIP and sarcoid treated with a single lung transplant had no adverse overall and CLAD-free survival. Recipients with conditions at risk for earlier CLAD, such as HP and NSIP, may benefit from double lung transplantation. Lung biopsies prior to transplantation may aid in donor lung allocation among patients with ILD and optimize organ utilization.