Clinical Characteristics, Outcomes, and Distribution Patterns of Pathogens Causing Respiratory Infections in Lung Retransplant Recipients

<i>Introduction</i>: With advances in surgical techniques and immunosuppressive therapies, lung retransplantation has become a viable option for patients experiencing graft failure. However, retransplantation is associated with inferior clinical outcomes, and infection remains a leading cause of morbidity and mortality in lung retransplant recipients. <i>Objectives</i>: This study examined clinical characteristics, outcomes, and microbial spectra of respiratory infections in lung retransplant recipients. <i>Methods</i>: This retrospective case-control study, conducted at two tertiary care centers, included 10 lung retransplant patients and 20 matched primary lung transplant patients. Respiratory pathogens identified using bronchoalveolar lavage (BAL) were compared between two groups over a two-year post-transplantation period. <i>Results</i>: Pulmonary hypertension was more prevalent in the retransplant group (<i>p</i> = 0.030). Five-year mortality and infection-related mortality were higher in the retransplant group (both <i>p</i> = 0.015), along with longer hospital and intensive care unit stays (<i>p</i> = 0.035 and 0.017, respectively). BAL cultures revealed distinct temporal patterns: <i>Elizabethkingia</i> predominated early (31.6% within 1 month) in the retransplant group, with <i>Pseudomonas</i> increasing gradually. The primary transplant group demonstrated a more heterogeneous distribution, with <i>Acinetobacter</i>, <i>Pseudomonas</i>, and <i>Enterococcus</i> detected early. <i>Conclusions</i>: Retransplant recipients exhibited worse clinical outcomes and a distinct temporal distribution of respiratory pathogens. Particularly, the high incidence of <i>Elizabethkingia</i> in lung retransplant recipients highlights the need for center-specific infection surveillance and tailored preventive strategies to improve retransplantation outcomes.