Neutropenia and Outcomes in Lung Transplant Recipients

Abstract

<h3>Purpose</h3> Lung transplantation is a lifesaving therapy for patients with advanced lung disease. However, graft rejection, neutropenia, and subsequent infection are common complications in patients' postoperative courses. While neutropenia is common post-transplant, its relationship to outcomes remains ill-defined. We investigated the relationship between severity and timing of neutropenia and outcomes after lung transplantation. <h3>Methods</h3> We retrospectively assessed absolute neutrophil values in the 12-month postoperative period of 209 lung transplant recipients at Northwestern Memorial Hospital from 2014-2021. Neutropenia is defined as an absolute neutrophil count <1500 cells/uL. We evaluated the correlation between neutropenia and the following outcomes: death within 1 year, presence of graft rejection, the severity of rejection, and infection with <i>Aspergillus</i>. The data was analyzed using R 4.0.2 (The R Foundation for Statistical Computing http://www.R-project.org). Packages Performance Analytics and ggplot2 were used in addition to core R. <h3>Results</h3> We evaluated 209 lung transplant recipients with an average age of 60. Neutropenia was present in 133(64%) patients during the 12-month postoperative period. There was no clear relationship between neutropenia and 1 year mortality(p=0.52), presence of graft rejection(p=0.75), severity of rejection(p=0.41) and <i>Aspergillus</i> infection(p=0.75). <h3>Conclusion</h3> Neutropenia is highly prevalent in lung transplant recipients, representing nearly 2/3 of our cohort. However, the clinical significance of this finding is not clear because we showed that the incidence of neutropenia had no significant relationship with the postoperative outcomes. Additional analysis of current data to determine if the severity of neutropenia (mild vs. moderate vs. severe), the timing of first neutropenic episode post-transplant, and frequency within the first year will be conducted to fully establish the impact of neutropenia on patients outcomes after lung transplantation.