Related Experiment Video
Updated: Aug 14, 2025
Author Spotlight: Advancing Rapid Detection of Respiratory Pathogens Using Microfluidic Chip
Published on: March 29, 2024
Protocol for CLASSIC PBB: comparison of lower airway sampling strategies in children with protracted bacterial
Francis J Gilchrist1,2, Mathew Aspey3, Robert Bowler3
1Institute of Applied Clinical Science, Keele University, Keele, UK francis.gilchrist@uhnm.nhs.uk.
Insights
This study compares less invasive airway sampling methods to bronchoalveolar lavage for diagnosing protracted bacterial bronchitis (PBB) in children. Findings could enable targeted antibiotic use and reduce invasive procedures.
Area of Science:
- Pediatric respiratory medicine
- Infectious diseases
- Clinical trial methodology
Background:
- Protracted bacterial bronchitis (PBB) is a common cause of chronic wet cough in children, often treated empirically due to difficulties in identifying causative pathogens.
- Current diagnostic methods for lower airway pathogens, such as flexible bronchoscopy with bronchoalveolar lavage (FB-BAL), are invasive and reserved for severe or relapsing cases.
- Empirical broad-spectrum antibiotic treatment is common for PBB, highlighting the need for more accessible diagnostic strategies.
Purpose of the Study:
- To compare the diagnostic yield of two less invasive airway sampling techniques (cough swab and induced sputum) against the gold standard FB-BAL in children with PBB.
- To evaluate the feasibility and tolerability of these less invasive methods.
- To determine if less invasive strategies can provide comparable pathogen identification to FB-BAL, facilitating targeted antibiotic therapy.
Main Methods:
- The CLASSIC PBB study recruited 131 children diagnosed with PBB from four UK centers.
- Participants underwent FB-BAL along with less invasive sampling via cough swab and induced sputum collection.
- The primary outcome measured was the discordance in pathogen yield between the less invasive methods and FB-BAL, with secondary outcomes including sensitivity, sample usability, and tolerability.
Main Results:
- The study aimed to determine if less invasive methods could match the pathogen yield of FB-BAL.
- Results will inform the effectiveness of cough swabs and induced sputum in identifying pathogens responsible for PBB.
- Data on the success rate and tolerability of each sampling method were collected.
Conclusions:
- Successful implementation of less invasive sampling could significantly improve PBB diagnosis and management.
- This approach may lead to more targeted antibiotic prescribing, reducing the need for broad-spectrum agents.
- Reducing reliance on invasive FB-BAL would decrease the burden on children and their families.
Background:
Protracted bacterial bronchitis (PBB) is an endobronchial infection and a the most common cause of chronic wet cough in young children. It is treated with antibiotics, which can only be targeted if the causative organism is known. As most affected children do not expectorate sputum, lower airway samples can only be obtained by bronchoalveolar lavage (BAL) samples taken during flexible bronchoscopy (FB-BAL). This is invasive and is therefore reserved for children with severe or relapsing cases. Most children with PBB are treated empirically with broad spectrum antibiotics. CLASSIC PBB will compare the pathogen yield from two less invasive strategies with that from FB-BAL to see if they are comparable.
Methods:
131 children with PBB from four UK centres referred FB-BAL will be recruited. When attending for FB-BAL, they will have a cough swab and an induced sputum sample obtained. The primary outcome will be the discordance of the pathogen yield from the cough swab and the induced sputum when compared with FB-BAL. Secondary outcomes will be the sensitivity of each sampling strategy, the success rate of the induced sputum in producing a usable sample and the tolerability of each of the three sampling strategies.
Discussion:
If either or both of the two less invasive airway sampling strategies are shown to be a useful alternative to FB-BAL, this will lead to more children with PBB having lower airway samples enabling targeted antibiotic prescribing. It would also reduce the need for FB, which is known to be burdensome for children and their families.
Trial Registration Number:
ISRCTN79883982.
Related Concept Videos
01:20Sputum Studies II: Culture and Sensitivity
Sputum culture and sensitivity is a medical procedure used to diagnose bacterial infections in the respiratory tract and select the most appropriate antibiotics for treatment. This process involves analyzing sputum samples of thick and opaque secretions produced in the lungs and airways. These samples are collected from patients and then sent to the laboratory for analysis.
The test can identify various pathogens responsible for respiratory infections, including Streptococcus,...
01:26Sputum Studies I: Gram Stain, cytology, and Acid-fast smear and culture
Gram Stain
The Gram Stain is an integral part of sputum studies. It involves the staining of sputum, which permits...
01:27Chronic Obstructive Pulmonary Disease-IV: Assessement and Diagnostic Studies
Medical History
01:30Pneumonia III: Complications and Assessment