Wet cough in children: infective and inflammatory characteristics in broncho-alveolar lavage fluid

Area of Science:

• Pediatric Pulmonology
• Infectious Diseases
• Respiratory Inflammation

Background:

• Wet cough is a common symptom in pediatric respiratory illnesses.
• Understanding the link between cough type and underlying airway inflammation is crucial for diagnosis and treatment.
• Lower airway infections can be caused by bacteria, viruses, or a combination of both.

Purpose of the Study:

• To investigate the association between cough nature (wet vs. dry) and the presence of lower airway infections in children.
• To determine the relationship between cough characteristics and the severity of neutrophilic airway inflammation.
• To test the hypothesis that viral-bacterial co-infection is linked to wet cough and heightened neutrophilic inflammation.

Main Methods:

• Prospective recruitment of 232 children undergoing flexible bronchoscopy.
• Classification of participants into wet cough, dry cough, or no cough groups based on symptoms.
• Collection of broncho-alveolar lavage (BAL) samples and clinical data to assess infection and inflammation markers.

Main Results:

• Children with wet cough were significantly more likely to have lower airway bacterial, viral, or viral-bacterial co-infections.
• Wet cough was associated with heightened airway neutrophilia compared to dry or no cough.
• Viral-bacterial co-infection showed the highest median neutrophil percentage, indicating maximal inflammation.

Conclusions:

• Cough nature, particularly wet cough, serves as a potential indicator of lower airway infection in children.
• The severity of neutrophilic airway inflammation is closely linked to the type of lower airway infection.
• Viral-bacterial co-infections are associated with the most severe neutrophilic airway inflammation and wet cough presentation.