Much effort has been devoted to the identification of immunologically important factors in
tuberculous pleurisy (
TBP) and malignant
pleurisy (MP) to improve the differential diagnosis of the two major causes of lymphocyte-dominant
pleurisy. This study evaluated the immunoreactivity and potential diagnostic utility of both host (
cytokines and
chemokines) and pathogen (mycobacterial
proteins) factors in
pleural effusions. Effusion samples were collected from 41 patients with MP caused by
lung cancer and from 81 patients with
TBP. The concentrations of nine
cytokines and
chemokines (
interleukin (
IL)-12 p40,
interferon (IFN)-gamma,
tumor necrosis factor (
TNF)-alpha, IL-6, IL-10, CXCL8/IL-8, CXCL10/IP-10, CCL3/MIP-1alpha, and CCL4/
MIP-1beta) and antibody responses (
IgG,
IgM, and
IgA) against five
Mycobacterium tuberculosis antigens (early secreted antigenic target (ESAT)-6, 30-kDa, MTB12, 38-kDa, and a
heparin-binding hemagglutinin (HBHA)) were determined in pleural fluids using
enzyme-linked
immunosorbent assays (ELISA). In the logistic regression, IFN-gamma (odds ratio, 7.178; 95% confidence interval (CI), 2.258-22.817; p=0.001),
IL-12 p40 (odds ratio, 11.037; 95% CI, 3.38-36.037; p<0.001), and
IL-6 (odds ratio, 3.295; 95% CI, 1.147-9.463; p=0.027) were found to be statistically significant
cytokines predicting tuberculous from malignant effusions. Although
IgG responses to all of the M.
tuberculosis antigens tested were significantly higher in effusions from
TBP (p<0.001) compared with those from MP, the logistic regression showed
IgG levels for ESAT-6 and MTB12 to be statistically significant for differentiation of
TBP from MP. HBHA showed the highest sensitivity of
IgM antibody responses in
TBP in comparison with other
antigens. These data indicate that selected mycobacterial
antigens (ESAT-6 and MTB12) and
cytokine markers (IFN-gamma, IL-12p40, and IL-6) provide useful information for differentiating tuberculous and malignant effusions in clinical practice.