Infections in autoimmune pulmonary alveolar proteinosis: a large retrospective cohort
Axelle Mabo, Raphaël Borie, Lidwine Wémeau-Stervinou, Y. Uzunhan, E. Gomez, Grégoire Prévôt, Martine Reynaud‐Gaubert, Julie Traclet, Emmanuel Bergot, J. Cadranel, S. Marchand‐Adam, Anne Bergeron, Élodie Blanchard, Benjamin Bondue, Philippe Bonniaud, Arnaud Bourdin, Pierre‐Régis Burgel, Sandrine Hirschi, Charles‐Hugo Marquette, S. Quétant, Hilario Nunès, Cécile Chenivesse, Bruno Crestani, Yoann Guirriec, Delphine Monnier, Cédric Menard, Pierre Tattevin, Vincent Cottin, David Luque-Paz, S. Jouneau
Abstract
BACKGROUND: Autoimmune pulmonary alveolar proteinosis (aPAP) is a rare disease, predisposing to an increased risk of infection. A complete picture of these infections is lacking. RESEARCH QUESTION: Describe the characteristics and clinical outcomes of patients diagnosed with aPAP, and to identify risk factors associated with opportunistic infections. METHODS: We conducted a retrospective cohort including all patients diagnosed with aPAP between 2008 and 2018 in France and Belgium. Data were collected using a standardised questionnaire including demographics, comorbidities, imaging features, outcomes and microbiological data. RESULTS: spp was the main pathogen identified (n=10). Thirty-five (34%) patients were hospitalised due to infection. In univariate analysis, male gender was associated with opportunistic infections (p=0.04, OR=3.88; 95% CI (1.02 to 22.06)). Anti-granulocyte macrophage colony-stimulating factor antibody titre at diagnosis was significantly higher among patients who developed nocardiosis (1058 (316-1591) vs 580 (200-1190), p=0.01). Nine patients had died (9%), but only one death was related to infection. INTERPRETATION: Patients with aPAP often presented with opportunistic infections, especially nocardiosis, which highlights the importance of systematic search for slow-growing bacteria in bronchoalveolar lavage or whole lung lavage.