Relationship between airway hyperresponsiveness to mannitol and adenosine monophosphate

Area of Science:

• Pulmonology
• Allergy and Immunology
• Respiratory Medicine

Background:

• Airway hyperresponsiveness (AHR) assessment is crucial for asthma diagnosis and management.
• Indirect bronchoconstrictor stimuli offer a noninvasive method for evaluating AHR.
• Adenosine monophosphate (AMP) is a known indirect bronchoconstrictor used in AHR testing.

Purpose of the Study:

• To investigate the relationship between AHR induced by inhaled adenosine monophosphate (AMP) and mannitol.
• To determine if mannitol can serve as a surrogate for AMP in AHR assessment.
• To explore the correlation between different thresholds of AMP and mannitol response.

Main Methods:

• A study involving fifteen mild-to-moderate atopic asthmatic patients.
• Measurement of threshold AMP concentration and mannitol dose to induce a specific fall in FEV1 (Forced Expiratory Volume in 1 second).
• Two separate screening days were used to assess the reproducibility and reliability of the measurements.

Main Results:

• A highly significant positive correlation was observed between AMP and mannitol thresholds.
• Pearson correlation coefficients ranged from 0.68 to 0.83 (P < 0.005), indicating a strong association.
• Specific results included AMP PC20 vs. mannitol PD15 (r=0.80), AMP PC15 vs. mannitol PD15 (r=0.83), and AMP PC10 vs. mannitol PD10 (r=0.68).

Conclusions:

• A significant association exists between the threshold concentrations of AMP and mannitol that cause a defined reduction in FEV1.
• Inhaled mannitol demonstrates potential as a reliable indirect bronchoconstrictor for AHR assessment.
• Further research is recommended to explore mannitol's relationship with other inflammatory markers in asthma.