difficulty including the last participants

Cystic fibrosis requires regular monitoring of bacterial colonization of sputum. The collection is done during scheduled consultations or urgently during exacerbations during the respiratory physiotherapy session, which is increasingly often associated with nebulization of Hypertonic Salt Serum (SSH). This allows, compared to simple expectoration, to obtain a greater density and diversity of germs. However, no study has focused on researching the precise place of origin of the collected secretions. Our aim is therefore to compare, in this pilot study in 20 adolescents suffering from cystic fibrosis and regularly followed at the pediatric CRCM, the ratio between squamous cells (CM, ENT origin) and broncho-alveolar cells in sputum obtained spontaneously and induced with of the SSH (collaboration with Professor Roll). The secondary criteria are the CM/bronchial cell ratio, the CM/alveolar macrophage ratio, cell viability and microbiological diversity. The hypothesis of this research is as follows: the nebulization of SSH before expectoration makes it possible to obtain a greater quantity of secretions from the broncho-alveolar sphere than during simple expectoration. In the cohort of 165 patients followed at the pediatric CRCM of Marseille, only 25 patients correspond to the inclusion criteria: they are between 12 and 17 years old, master autogenous drainage as well as spontaneous expectoration in sufficient quantity to carry out the research. They must also have been in stable clinical condition for at least one month. Taking into account the non-inclusion criteria (refusal to participate, systemic antibiotic therapy, respiratory decompensation or upper airway infection, SpO2 less than 92% before nebulization, appearance of hemoptysis in the last three months), the number of subjects is fixed. To 20. Each patient participates in a single day of hospitalization scheduled at the pediatric CRCM: at 9 a.m. simple expectoration and at 1 p.m., expectoration caused by SSH. The subject is therefore his own witness. The study inclusion period is one year.

Inclusion Criteria:

• Adolescent between 12 and 17 years old with definite cystic fibrosis (two CFTR gene mutations identified and positive sweat test)
• Patient followed at the pediatric CRCM of Marseille
• Patient able to expectorate spontaneously and master autogenous drainage
• Patient in stable clinical condition for 1 month

Exclusion Criteria:

• Patient refusing the study
• Patient under systemic antibiotic therapy
• Patient with respiratory decompensation or upper airway infection
• Patient with oxygen saturation < 92% before nebulization
• Patient with hemoptysis in the last 3 months
• Patients with decompensated heart failure