Bronchoalveolar cytokine profile differentiates Pulmonary Langerhans cell histiocytosis patients from other smoking-related interstitial lung diseases.

"Declarations Ethics approval and consent to participateNo animal experiments are included in the study. The studies involving human participants were reviewed and approved by Hospital de la Santa Creu i Sant Pau ethics committee (IIBSP-LAN-2013–39). All patients signed an informed consent before their inclusion in the study. The patients/participants provided their written informed consent to participate in this study. Consent for publicationNot applicable. Competing interestsThe authors declare that there are no competing interests. Competing interests The authors declare that there are no competing interests."

"Funding This study was funded by the Fundación Mutua Madrileña and the Spanish Respiratory Society (SEPAR) and by grants PI14CIII/00055, PI17CIII/00012, PI20CIII/00018 from the FIS."