Inclusion Criteria:  Patient over the age of 18 who is not under legal protection  Patients with CF according to the diagnostic criteria of the Cystic Fibrosis Foundation including:  15 patients with severe mutation but not chronically infected with PA and not treated with lumacaftor / ivacaftor 15 patients homozygous phe508del, chronically infected with PA and not treated with lumacaftor / ivacaftor 15 patients homozygous phe508del, chronically infected with PA and treated with lumacaftor / ivacaftor 15 hospitalized patients for respiratory exacerbation 40 patients initiating Ivacaftor-Tezacaftor-Elexacaftor treatment. No change in baseline treatment for 15 days (including antibiotic treatment). Patient affiliated to a social security system Free, informed and written consent, dated and signed by the patient and the investigator, at the latest on the day of inclusion and before any action required by the study.  Exclusion Criteria:  Informed consent impossible to obtain Involvement in an interventional research protocol in the previous 3 months if exclusion directive was given in this protocol.