Exhaled volatile organic compounds for diagnosis and monitoring of asthma

Table 3 Discriminative volatile organic compounds of different asthma subtypes and inflammatory disease characteristics

Inflammatory characteristics	Identified compound	Ref.
Eosinophilic asthma vs paucigranulocytic asthma	Hexane 2-hexanenone	[14]
Neutrophilic asthma vs eosinophilic asthma	3,7-dimethylnonane; Nonanol 1-propanol	[14]
Neutrophilic asthma vs paucigranulocytic asthma	3-tetradecane pentadecane nonane undecane (isomer of 3,7-dimethylnonane)	[14]
Neutrophilic asthma vs paucigranulocytic and eosinophilic asthma	Nonanal propanol hexane	[14]
Neutrophilic sputum cell ≥ 40%	Cyclopentene, 1,3-dimethyl-2-(1-methylethyl) C10H18 Naphthalene, 2,7-dimethyl	[39]
Eosinophilic sputum cell ≥ 2%	Camphene (7a-Isopropenyl-4,5-dimethyloctahydroinden-4-yl) methanol Bicyclo[4.1.0]hept-2-ene, 3,7,7-trimethyl Cyclohexene-4-methylene	[39]
Blood eosinophils level	2-octene; 3,3-Dimethyloctane; 1-Fluorododecane; 2,6,6-Trimethyldecane	[29]