Bronchial hyperresponsiveness and bacterial respiratory infections

Area of Science:

• Pulmonary Medicine
• Infectious Diseases
• Allergy and Immunology

Background:

• Bacterial respiratory tract infections are implicated in bronchospasm and the progression of chronic obstructive pulmonary disease (COPD).
• Conditions like bronchiectasis, cystic fibrosis, and croup exhibit exaggerated airway reactivity, potentially influenced by bacterial presence.
• Bacterial inhalation, including Haemophilus influenzae, has been linked to bronchial obstruction.

Purpose of the Study:

• To investigate the prevalence of bacterial infections during acute asthma exacerbations.
• To assess the role of antibiotic therapy in managing bacterial respiratory infections and associated airway hyperreactivity in asthmatic patients.

Main Methods:

• A multicenter study of 193 patients with acute asthma exacerbation between January 1989 and June 1990.
• Bacterial identification in sputum samples from patients.
• Evaluation of antibiotic treatment (cefaclor) in a subset of 12 patients with high airway reactivity.

Main Results:

• Bacteria were detected in the sputum of 52% of patients during acute asthma exacerbations.
• Commonly isolated bacteria included Streptococcus pneumoniae, Streptococcus pyogenes, Staphylococcus aureus, Moraxella catarrhalis, and H. influenzae.
• A 10-day course of cefaclor in 12 patients resulted in microbiologic cure and a slight, though not statistically significant, change in airway reactivity.

Conclusions:

• Antibiotic therapy plays a role in controlling bronchial hyperreactivity secondary to bacterial respiratory infections in asthmatic patients.
• The efficacy of antibiotics is most apparent after the resolution of airway inflammation.
• Strategies to minimize airway reactivity are crucial for preventing or reversing respiratory failure in asthma and COPD exacerbations.