For these reasons, useful BTK inhibitor classification tree models and diagnostic models have been promptly built up by this technique in several medical realms such as cancer, autoimmune disease, haematological disease and mental diseases [16–19]. In our study, we used the data of a training set to construct a classification tree model that help accurately discriminate patients with active TB from patients with other respiratory diseases and healthy people, and then we applied this model to a test set to verify its performance of classification. Patients.  According to the case definitions described elsewhere, 75 patients

with active TB (active TB group) and 103 individuals (non-TB group) including 43 patients with common respiratory diseases (CRD subgroup) and 60 healthy controls (HC subgroup) were recruited from 309th hospital of Chinese PLA. These patients were randomly divided into two sets: a training set and a test set. Our study was approved by the ethics committee of Peking Union Medical College Hospital, and informed consent was obtained from each patient and volunteer. Case definitions.  Diagnosis INCB018424 concentration of active TB was based on several criteria as follows: (1) sputum smear positive of

acid-fast bacilli or culture positive of M.tb, (2) positive TST, (3) specific symptoms such as persistent cough, weight loss, and night sweats and (4) characteristic changes of chest X-ray (CXR) like lung with cavities in upper lobes. Sputum smear-positive TB (SPP-TB) and smear-negative TB (SNP-TB) patients were classified according to widely accepted criteria [20], and all patients with SNP-TB were ultimately confirmed if their symptoms and CXR turned better after 3 months of anti-TB treatment. TST was performed on active TB group in their first visit according to standard intradermal

Mantoux test with 5 IU purified protein derivative of Bacillus Calmette-Guerin (BCG) (Chengdu institute of biological product, Sichuan, China) and read after 72 h. An induration of ≥5 mm is considered a positive test [21]. Anyone who met the criteria above or had a history of contact with active TB patients was excluded from the non-TB Dehydratase group. To rule out latent patients with TB from this group, individuals that have received BCG vaccination before should be negative in IGRA (QuantiFERON®-TB Gold in Tube; Cellestis, Carnegie, Vic., Australia), which was performed according to the manufacturer’s instructions (cut-off value ≥ 0.35 IU/ml), and other individuals in the non-TB group should be negative of TST. In CRD subgroup, patients with lung cancer and sarcoidosis were diagnosed according to their biopsy evaluation, while patients with pneumonia, COPD, and bronchiectasia were diagnosed based on their clinical manifestations, radiographic features and prompt clinical response to regular therapy.