Sputum-to-serum hydrogen sulphide ratio as a novel biomarker of predicting future risks of asthma exacerbation.

Abstract

BACKGROUND:

Increased level of hydrogen sulphide (H2 S) in sputum is reported to be a new biomarker of neutrophilic airway inflammation in chronic airway disorders. However, the relationship between H2 S and disease activity remains unclear.

OBJECTIVE:

We investigated whether H2 S levels could vary during different conditions in asthma.

METHOD:

H2 S levels in sputum and serum were measured using a sulphide-sensitive electrode in 47 stable asthmatic subjects (S-BA), 21 uncontrolled asthmatic subjects (UC-BA), 26 asthmatic subjects with acute exacerbation (AE-BA) and 15 healthy subjects. Of these, H2 S levels during stable, as well as exacerbation states, were obtained in 13 asthmatic subjects.

RESULTS:

Sputum H2 S levels were significantly higher in the AE-BA subjects compared to the UC-BA and healthy subjects (P < .05). However, serum H2 S levels in the AE-BA subjects were lower than in the S-BA subjects (P < .001) and similar to those in healthy subjects. Thus, the sputum-to-serum ratio of H2 S (H2 S ratio) in the AE-BA subjects was significantly higher than in the S-BA, UC-BA and healthy subjects (P < .05). Among all subjects, sputum H2 S levels showed a trend to decrease with FEV1 %predicted and significantly positive correlations with sputum neutrophils (%), sputum IL-8 and serum IL-8. A multiple linear regression analysis showed that sputum H2 S was independently associated with increased sputum neutrophils (%) and decreased FEV1 %predicted (P < .05). The cut-off level of H2 S ratio to indicate an exacerbation was ≥0.34 (area under the curve; 0.88, with a sensitivity of 81.8% and specificity of 72.7%, P < .001). Furthermore, half of the asthmatic subjects with H2 S ratios higher than the cut-off level experienced asthma exacerbations over the following 3 months after enrolment.

CONCLUSIONS:

The H2 S ratio may provide useful information on predicting future risks of asthma exacerbation, as well as on obstructive neutrophilic airway inflammation as one of the non-Th2 biomarkers, in asthma.

• Authors: Y Suzuki, J Saito, M Kikuchi, M Uematsu, A Fukuhara, S Sato, M Munakata
• Journal: Clinical and experimental allergy : journal of the British Society for Allergy and Clinical Immunology (Clin Exp Allergy) Vol. 48 Issue 9 Pg. 1155-1163 (09 2018) ISSN: 1365-2222 [Electronic] England
• PMID: 29758106 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2018 John Wiley & Sons Ltd.

Chemical References

• Biomarkers
• Cytokines
• Hydrogen Sulfide

Topics

• Adult
• Aged
• Asthma (diagnosis, immunology, metabolism)
• Biomarkers
• Cross-Sectional Studies
• Cytokines (metabolism)
• Disease Progression
• Female
• Humans
• Hydrogen Sulfide (blood, metabolism)
• Male
• Middle Aged
• Neutrophils (immunology, metabolism)
• Prognosis
• ROC Curve
• Respiratory Function Tests
• Sputum (metabolism)
• Th1 Cells (immunology, metabolism)
• Th2 Cells (immunology, metabolism)