Legionnaires’ Disease in Solid Organ Transplant Recipients
Résumé
BACKGROUND: Legionnaires’ disease (LD) is a rare, life-threatening opportunistic bacterial
infection that poses a significant risk to patients with impaired cell-mediated immunity such
as solid organ transplant recipients (SOTRs). However, the epidemiologic features, clinical
presentation, and outcomes of LD in this population are poorly described.
RESEARCH QUESTION: What are the clinical manifestations, radiologic presentation, risk
factors for severity, treatment, and outcome of LD in SOTRs?
STUDY DESIGN AND METHODS: In this 10-year multicenter, retrospective cohort study in
France, where LD notification is mandatory, patients were identified by hospital discharge
databases. Diagnosis of LD relied on positive culture findings from any respiratory sample,
positive urinary antigen test (UAT) results, positive specific serologic findings, or a combination thereof. Severe LD was defined as admission to the ICU.
RESULTS: One hundred one patients from 51 transplantation centers were eligible; 64 patients
(63.4%) were kidney transplant recipients. Median time between transplantation and LD was 5.6
years (interquartile range, 1.5-12 years). UAT results were positive in 92% of patients (89/97).
Among 31 patients with positive culture findings in respiratory samples, Legionella pneumophila
serogroup 1 was identified in 90%. Chest CT imaging showed alveolar consolidation in 98% of
patients (54/57), ground-glass opacity in 63% of patients (36/57), macronodules in 21% of patients (12/57), and cavitation in 8.8% of patients (5/57). Fifty-seven patients (56%) were hospitalized in the ICU. In multivariate analysis, severe LD was associated with negative UAT findings
at presentation (P¼ .047), lymphopenia (P ¼ .014), respiratory symptoms (P¼ .010), and pleural
effusion (P ¼ .039). The 30-day and 12-month mortality rates were 8% (8/101) and 20% (19/97),
respectively. In multivariate analysis, diabetes mellitus was the only factor associated with 12-
month mortality (hazard ratio, 3.2; 95% OR, 1.19-8.64; P ¼ .022).
INTERPRETATION: LD is a late and severe complication occurring in SOTRs that may present
as pulmonary nodules on which diabetes impacts its long-term prognosis.