Sputum-to-serum hydrogen sulfide ratio in COPD

Area of Science:

• Biochemistry
• Pulmonary Medicine
• Biomarker Discovery

Background:

• Hydrogen sulfide (H₂S) is a gasotransmitter produced by respiratory cells.
• H₂S may play a role in cellular signaling within the respiratory system.

Purpose of the Study:

• To investigate H₂S levels in serum and sputum as potential biomarkers for COPD.
• To evaluate the sputum-to-serum H₂S ratio as an indicator of COPD exacerbation.

Main Methods:

• Measured H₂S levels in sputum and serum using a sulfide-sensitive electrode.
• Studied patients with stable COPD, acute exacerbation of COPD (AE-COPD), healthy smokers, and healthy non-smokers.
• Calculated the sputum-to-serum H₂S ratio (H₂S ratio).

Main Results:

• AE-COPD subjects had higher sputum H₂S and lower serum H₂S compared to other groups.
• The H₂S ratio was significantly higher in AE-COPD subjects (p<0.001).
• An H₂S ratio ≥0.44 demonstrated 93.1% sensitivity and 84.5% specificity for indicating exacerbation.

Conclusions:

• The sputum-to-serum H₂S ratio is a promising biomarker for COPD.
• This ratio can indicate obstructive neutrophilic inflammation.
• The H₂S ratio may help identify ongoing COPD exacerbations.