Abstract and Introduction
Abstract
The aim of the present study is to evaluate the epidemiology, etiology and prognosis of pneumonia in lung transplant (LT) recipients. This is a prospective, multicenter study of a consecutive cohort of LT recipients in Spain. From September 2003 to November 2005, 85 episodes of pneumonia in 236 LT recipients were included (incidence 72 episodes per 100 LT/year). Bacterial pneumonia (82.7%) was more frequent than fungal (14%) and viral pneumonia (10.4%). The most frequent microorganisms in each etiological group were Pseudomonas aeruginosa (n = 14, 24.6%), CMV (n = 6, 10.4%) and Aspergillus spp. (n = 5, 8.8%). Incidence of Aspergillus spp. and CMV pneumonia is lower than previously reported, probably due to the spread of universal prophylaxis. Pneumonia caused by viruses appeared significantly later than pneumonia due to gram-negative bacilli, fungi and those without known etiology (p < 0.01, p = 0.03 and p = 0.02, respectively). The routine use of ganciclovir has changed the natural history of CMV infection, so that pneumonia appears later, once prophylaxis is suspended. The probability of survival during the first year of follow-up was significantly higher in the multivariate analysis in LT recipients who did not have a pneumonia episode compared with those that had at least one episode (p < 0.01).
Introduction
Lung transplant (LT) recipients are particularly susceptible to pneumonia in comparison with other solid organ transplant (SOT) recipients or similarly immunosuppressed patients. In addition to the generalized immunosuppression by antirejection medications, the lung allograft is denervated, the cough reflex is depressed, mucociliary clearance is decreased and lymphatic drainage is disrupted. Pneumonia is a major cause of morbidity and mortality in LT recipients and mortality for pneumonia is higher in this group of patients than in other SOT recipients.
The etiology of pneumonia in LT patients is very varied and includes opportunistic and hospital acquired microorganisms. The clinical symptoms and signs are frequently modified by the immunosuppression therapy. Antimicrobial therapy is limited by the interactions with immunosuppressants and a higher incidence of adverse events, determining a poor prognosis. Prompt diagnosis and treatment is necessary to prevent poor outcomes.
An understanding of the temporal relationship between LT, the beginning of immunosuppression and the risk for developing pneumonia of different aetiologies may assist the appropriate treatment.
However, the information available on pneumonia in LT recipients is scarce. Most of the studies describe pneumonia in the context of the whole infectious events in the postransplant period or describe pneumonia caused by discrete microorganisms, usually cytomegalovirus,Aspergillus spp. and other fungal infections or Nocardia. To our knowledge, there are no recent studies that specifically analyze this complex syndrome of pneumonia in LT recipients. The aim of the present study is to evaluate the epidemiology, etiology and prognosis of pneumonia in LT centers in Spain.