Pneumonia in lung transplant recipients: the role of donor, recipient, and hospital-acquired microorganisms.

OBJECTIVE: Donor-derived disease is an inherent risk in solid organ transplantation, especially lung transplantation (LTx), because of direct contact between the organ and the external environment, and the consequences of lung denervation after LTx. We sought to demonstrate the burden of pneumonia after LTx in a large center in Brazil, characterizing the main source of infection and its associated mortality. METHODS: We performed a retrospective analysis of all LTx procedures occurring between 2017 and 2023 at a public center in Brazil. All microorganisms isolated from the donor BAL fluid and the recipient bronchial secretions at organ harvest were compared with those found by postoperative day 14 and classified as donor-derived, recipient colonization-related, or hospital-acquired pneumonia. We analyzed the characteristics of donors and recipients, as well as the associated mortality. RESULTS: Donor-derived pneumonia was found in 8/149 patients (5.36%) who received lungs from infected donors. In all cases, donor-derived pneumonia was due to gram-negative bacilli, all of which showed drug resistance, causing a 50% mortality rate. Recipient colonization-related pneumonia occurred in 14/107 patients (13%), being mostly due to Pseudomonas aeruginosa (in 58.8%), with a 28.6% risk of death. Hospital-acquired pneumonia occurred in 17 of 217 recipients (7.83%), being mainly due to Acinetobacter baumannii (in 20%), P. aeruginosa (in 15%), Klebsiella pneumoniae (in 10%), Stenotrophomonas maltophilia (in 10%), or Burkholderia cepacia (in 10%), with a mortality rate of 50%. CONCLUSIONS: Although infrequent, donor-derived pneumonia appears to be associated with high early mortality, comparable to that for hospital-acquired pneumonia. Recipient colonization-related and hospital-acquired pneumonia are linked to an increased chance of death, especially in patients colonized with P. aeruginosa and those with extensively drug-resistant bacteria, respectively.