Aetiology, clinical features, diagnostic studies, and outcomes of community-acquired pneumonia in kidney transplant recipients admitted to hospital: a multicentre retrospective French cohort study

ObjectivesTo assess the aetiology, clinical features, diagnostic studies and outcomes of community-acquired pneumonia (CAP) in a French cohort of hospitalized kidney transplant recipients.MethodsWe performed a retrospective, multicentre study in kidney transplant recipients admitted to ten French centres for CAP from January 2016 to December 2018. CAP discharge diagnoses were clinically and radiologically validated. We assessed a descriptive analysis of all confirmed CAP including medical ward and intensive care unit admissions.ResultsOne hundred sixty-five CAP episodes in 132 patients were included. Median time from transplantation to admission was 6.4 (interquartile range, 1.6–12.3) years, with corticosteroid exposure in 112/165 (67.9%) cases. Sputum culture was performed in 47/165 (28.5%) cases including 7/47 (14.9%) positive samples. Bronchoscopy was performed in 87/165 (52.7%) cases with pathogens identified in 39/87 (44.8%) cases. Microbiological studies led to identifying a respiratory pathogen in 64/165 (38.8%) CAP episodes including 11/64 (17.2%) polymicrobial cases. Among these 64 episodes, 75 microorganisms were identified; 46/75 (61.3%) were core respiratory pathogens and 29/75 (38.7%) were opportunistic or drug-resistant organisms including Pneumocystis jirovecii 9/75 (12%), Pseudomonas aeruginosa 5/75 (6.7%), multidrug-resistant Enterobacteriaceae 4/75 (5.3%), and Aspergillus 4/75 (5.3%). Patients required intensive care unit admission in 26/165 (15.8%) episodes, invasive ventilation in 20/165 (12.1%) cases, and 22/165 (13.3%) needed in-hospital dialysis.DiscussionCAP episodes occurred in kidney transplant recipients with a long history of immunosuppressive drug exposure. Diagnostic studies identified a microorganism in more than one-third of CAP episodes, including drug-resistant and opportunistic pathogens.