Background: Diagnosing chronic
pulmonary aspergillosis is a major challenge in clinical practice. The development and validation of a novel, sensitive and specific assay for diagnosing chronic
pulmonary aspergillosis is urgently needed. Methods: From April 2018 to June 2019, 53 patients with chronic
pulmonary aspergillosis (CPA), 32 patients with community-acquired
pneumonia (CAP) and 48 healthy controls were recruited from the First Affiliated Hospital of Guangzhou Medical University. Clinical characteristics and samples were collected at enrollment. All exhaled breath samples were analyzed offline using thermal desorption single-photon ionization time-of-flight mass spectrometry; to analyze the metabolic pathways of the characteristic
volatile organic compounds, serum samples were subjected to ultrahigh-performance liquid chromatography. Results: We identified characteristic
volatile organic compounds in patients with chronic
pulmonary aspergillosis, which mainly consisted of
phenol,
neopentyl alcohol,
toluene,
limonene and
ethylbenzene. These compounds were assessed using a logistic regression model. The sensitivity and specificity were 95.8 and 96.9% for discriminating patients in the CPA group from those in the CAP group and 95.8 and 97.9% for discriminating patients in the CPA group from healthy controls, respectively. The concentration of
limonene (m/z 136) correlated significantly positively with anti-Aspergillus fumigatus
IgG antibody titers (r = 0.420, P < 0.01). After antifungal treatment, serum
IgG and the concentration of
limonene (m/z 136) decreased in the subgroup of patients with chronic
pulmonary aspergillosis. Conclusions: We identified VOCs that can be used as
biomarkers for differential diagnosis and therapeutic response prediction in patients with chronic
pulmonary aspergillosis.