Study On Screening Of Characteristic VOCs From Exhaled Breath Of Pulmonary Cryptococcosis Patients

Pulmonary cryptococcosis is one of the most important fungal infections,and the incidence rate has been increasing in recent years.However,due to its lack of specific clinica manifestations of pulmonary cryptococcosis,it is easy to cause misdiagnosis and missed diagnosis.In addition,its diagnosis and antifungal treatment are expensive,which brings a huge economic burden to society and families.Therefore,pulmonary cryptococcosis urgently needs a new diagnostic method which is easy to deploy in primary hospitals.Breath diagnosis is non-invasive,simple,fast,and accurate,and it has been used in the diagnosis of many diseases.Furthermore,it has successfully detected the characteristic VOCs in the breath of patients with pulmonary aspergillosis.Thus,the breath diagnosis is expected to become a new method for diagnosis of pulmonary cryptococcosis.In this paper,a total of 53 subjects were detected by gas chromatography ion mobility spectrometry(GC-IMS),including 20 patients with pulmonary cryptococcosis and 33 healthy controls.And,a total of 19 VOCs were detected.By using orthogonal partial least squares-discriminant analysis(OPLS-DA),it was found that there was a clear distinction between the exhaled VOCs of patients with pulmonary cryptococcal disease and that of healthy controls.Furthermore,the potential characteristic VOCs for patients with pulmonary cryptococcosis were screened out,including 2-methyl-1-propanal,isopropyl benzene,2-pentanone,4-methyl-2-pentanone,butanal and hexanal.The potential characteristic VOCs were used to establish logistic regression model for fitting,the sensitivity was 100% and the specificity was 93.93%.In this paper,the breath of the subject was also collected by Tedlar bags,43 patients with pulmonary cryptococcosis and 50 healthy controls were detected by thermal desorption single photon ionization time-of-flight mass spectrometry(TD /SPI-MS).A total of 204 ions were detected.The OPLS-DA model was used to analyze the data matrix,and there was a good distinction between the pulmonary cryptococcosis group and the healthy control group.Furthermore,a total of 9characteristic ions were screened,including: m/z90?m/z62?m/z91?m/z208?m/z88?m/z222?m/z89?m/z210?m/z220.The logistic regression model was used for fitting,the sensitivity was 100% and the specificity was 90.70%.Both GC-IMS and SPI-MS were used to detect the exhaled breath VOCs of pulmonary cryptococcosis and healthy controls,and the potential characteristic VOCs in the breath of patients with pulmonary cryptococcosis were screened out.The whole research evaluate the feasibility of exhalation diagnosis,providing a basis for subsequent research of breath diagnosis.