Suzuki Y, et al. - Researchers examined the link between hydrogen sulphide (H₂S) levels and disease activity in asthma by investigating possible variations in H₂S levels during different conditions in asthma. Stable asthmatic subjects (S-BA), uncontrolled asthmatic subjects (UC-BA), asthmatic subjects with acute exacerbation (AE-BA) and healthy subjects were examined. Significantly higher sputum H₂S levels were detected in the AE-BA subjects vs the UC-BA and healthy subjects. The AE-BA subjects had lower serum H₂S levels, compared with the S-BA subjects, while these levels were similar to those in healthy subjects. Overall, H₂S ratio may have utility in the prediction of future risks of asthma exacerbation. It may offer useful information on obstructive neutrophilic airway inflammation as one of the non-Th2 biomarkers, in asthma.