Evaluation Of Serum Anti - PPD IgG Antibody In The Diagnosis Of Active Pulmonary Tuberculosis By ROC Analysis

Objective:To evaluate the diagnostic value of serum levels of anti-PPD Ig G specific antibodies in active pulmonary tuberculosis, we performed the study to determine ADA activity in the patients with pulmonary tuberculosis and normal people.Methods: We collected 32 newly diagnosed patients with active pulmonary tuberculosis in inpatient from June 2013 to March, 2014. The control group include 40 healthy examined people coming from Medical Examination Center. In another test, We collected 20 patients with tuberculous pleurisy, 20 patients with malignant pleural effusion.Exclusion criteria: Patients with other lung disease, severe heart failure, chronic liver kidney disease, malignant tumor, diabetes, autoimmune diseases, congenital or acquired immunodeficiency, accept systemic immunomodulatory or immunosuppressive therapy(including oral corticosteroids).We developed an indirect ELISA test to detect the anti-PPD Ig G specific antibodies in both active pulmonary TB group and the control group. And then ROC analysis was performed to evaluate the value of the test for the diagnosis of active pulmonary tuberculosis. ADA was measured by full automatic biochemical analyzer of Shimadzu Corporation Modular PI.Results:Compared with the healthy, the levels of levels of anti-PPD Ig G specific antibodies in active pulmonary tuberculosis patients increased,(1.297±1.109 and 2.832±1.578 respectively(P=0.002). Area under the ROC curve is 0.797(95CI, 0.643-0.950). The average of antibody levels of the control group plus SD as diagnostic cutoff point is appropriate. There were significantly different of blood ADA antibody concentration between active pulmonary tuberculosis group and healthy group(P<0.05)Conclusions: Serum anti-PPD Ig G antibody levels can be proposed as a diagnostic marker of active pulmonary tuberculosis. Determination of blood ADA in patients with pulmonary tuberculosis increased significantly,it can be used as a reference index for detecting tuberculosis.