OBJECTIVE: To compare the serum glycerophospholipid levels in the inflammatory subtypes of asthma by using targeted metabolomic analysis. METHODS: Demographic and clinical data were collected from 51 patients with asthma between January 2015 and December 2015. Routine blood and sputum induction tests were performed. Eosinophilic asthma was defined as induced sputum containing ⪖ 3% eosinophils, and neutrophilic asthma, as induced sputum containing ⪖ 71% neutrophils. Serum metabolic glycerophospholipid profile was determined by liquid chromatography-mass spectrometry. Differences in glycerophospholipid levels between eosinophilic and non-eosinophilic asthma and between neutrophilic and non-neutrophilic asthma were analyzed using partial least squares discriminant analysis. RESULTS: The serum lysophosphatidylglycerol level was significantly higher in the group with ⪖ 3% eosinophils in sputum than in the group with < 3% eosinophils in sputum. The area under the receiver-operating characteristic curve was ⪖ 70%. There was no significant difference in the serum metabolic glycerophospholipid profile between the group with sputum neutrophils ⪖ 71% and the group with sputum neutrophils < 71%. CONCLUSION Serum lysophosphatidylglycerol is produced abundantly in eosinophilic asthma and may be a biomarker of eosinophilic asthma. This information is helpful for identifying and tailoring treatment for the common asthma subtypes.
Adult ; Asthma ; blood ; immunology ; Eosinophils ; immunology ; Female ; Glycerophospholipids ; blood ; Humans ; Male ; Metabolomics ; Middle Aged ; Neutrophils ; immunology ; Sputum ; cytology ; immunology