Protracted Bacterial Bronchitis

The goal of this observational study is to improve the identification of biomarkers that predict disease progression and to assess the effectiveness of current therapies in children with asthma and protracted bacterial bronchitis. The main aim of the study is to evaluate the microbiome composition and diversity, cellular composition, and metabolomic profile. In addition, to assess their correlation on subsequent treatment and disease course in children with asthma, protracted bacterial bronchitis, and in those receiving inhaled glucocorticosteroids without a diagnosis of asthma. Participants will undergo fiberoptic bronchoscopy. During bronchoscopy, the performing physician will collect Bronchoalveolar lavage fluid samples for metagenomic and metabolomic analysis, as well as mucosal biopsies for histopathological evaluation.

Protracted bacterial bronchitis (PBB) is a problem in the lungs causing children to have a wet cough for more than 4 weeks. PBB is also known to start before and cause other lung diseases and to affect children's quality of life. It is difficult to know if a child has PBB. Listening to the lungs and measuring a child's breathing are usually normal and so a bronchoscopy (looking in the lungs with a camera) and a type of lung scan called CT are needed to diagnose PBB. These tests involve children being put to sleep under anaesthetic (bronchoscopy) or exposed to radiation (CT) and so are not performed often. PBB is difficult to treat and antibiotics are given for many weeks to make children better. Often this doesn't stop the cough and antibiotics need to be injected into the child to treat the infection. Children have to take large amounts of antibiotics and have regular physiotherapy to help their cough. The only way to know if a child is better is when their parents report their cough has improved which is often unreliable. In this study we will take pictures of children's lungs using a type of scan called MRI, which is safe and does not expose children to radiation. Children breathe in a gas called xenon which fills the lungs. If there is phlegm blocking parts of the lungs, the gas cannot get through and we can see the blockage. This type of picture is the best way to measure early lung disease in children with other lung conditions such as cystic fibrosis and bronchiectasis. Measuring lung disease early will make children with PBBs lives better and mean they have to take less antibiotics. In some children, it will also help to stop lifelong lung diseases such as bronchiectasis.

This project aims to assess the relationship between the microbiome and virome composition, the immune responses, and the respiratory health of children with protracted bacterial bronchitis (PBB). In addition, we aim to evaluate how the standard treatment with azithromycin interacts with the components of the microbiome, virome and immune biomarkers.

This is a prospective, single-center, two-arm (1:1), assessor-blinded, randomized controlled clinical trial that will be conducted in collaboration with the outpatient clinic of the third Pediatric Pulmonology Unit, "Attikon" University Hospital of Athens in Greece. The aim of the study is to investigate the effects of applying digital physiotherapy services in the management of specific clinical outcomes in children with chronic suppurative lung diseases, other than cystic fibrosis. The research question is whether airway clearance techniques and exercise training that are performed remotely using digital health services (DHSs) can improve functional and exercise capacity, as well as compliance with ACTs, compared to usual care. The intervention program includes airway clearance techniques (ACTs), as well as aerobic and strengthening exercises that can be implemented easily in an online setting at home with minimal equipment. The duration of the program will be 12 weeks, and the prescribed weekly regimen will consist of 50-minute remote sessions: two synchronous, supervised sessions conducted via the Vsee platform, and a minimum of one asynchronous, unsupervised session. Children will be encouraged to maintain daily adherence to the exercise protocol.

The AMIC study is a double-blind, placebo-controlled, multicenter, nationwide, randomized controlled academic pharmaceutical trial. OVERALL PRIMARY OBJECTIVES: * To study the clinical efficacy of antibiotics in children with chronic wet cough (CWC). * To study if duration of treatment with antibiotics in children with CWC has impact on efficacy or time to relapse of symptoms. OVERALL SECONDARY OBJECTIVE: -To study respiratory pathogens and the diversity/composition of airway and gut microbiome in children with CWC compared to healthy controls, and changes in pathogens/microbiome after treatment with antibiotics. OVERALL TERTIARY OBJECTIVE: -To study the role of inflammation, immunology, and genetics in children with chronic wet cough and suspicion of PBB to increase the knowledge of pathophysiological mechanisms associated with PBB. The study will include two different RCTs AMIC 1 and AMIC 2: AMIC 1: Participants will be randomly assigned to 14 days amoxicillin-clavulanate syrup or placebo. AMIC 2: Participants will be randomly assigned 1:1 to receive either 14 or 28 days with amoxicillin-clavulanate syrup.