Objective:To explore the clinical value of detection of sulfated glycosaminoglycan(GAG) segment and IgG antibody to tuberculosis(TB-IgG) to diagnose tuberculous pleuritis and malignant pleural effusion.Methods:Using the lung tumor antigen(LTA) diagnostic kit and tuberculosis antibody colloidal gold diagnostic kit to detecte the GAG and TB-IgG of serum and pleural fluid separately of 357 patients suffering from hydrothorax.We proceeded a retrospective study and then had statistical evidence.Results:The positive rate and specificity of GAG of pleural effusion of lung cancer patients were 80.3%(106/132)

88.4%

and that of serum were 54.5%(72/132)

90.2%.The positive rate and specificity of TB-IgG of pleural effusion of tuberculous pleuritis were 66.2%(102/154)

86.2%

and that of serum were 33.8%(52/154)

83.7%.The specificity of GAG

combined with TB-IgG by measuring the pleural fluid of tuberculous pleuritis and malignant pleural effusion would increase to 97.0% and 98.2% separately.Conclusion:Detection of GAG and TB-IgG of pleural fluid is helpul for diagnosis of tuberculous pleuritis and malignant pleural effusion.GAG combined with TB-IgG can act as differential diagnosis marker of tuberculous pleuritis and malignant pleural effusion for its higher specificity.