The numbers of different subsets of lymphocyte in tuberculous and malignant hydrothorax patients. The peripheral blood and hydrothorax mononuclear cells were stained with specific antibodies respectively. The numbers of blood and hydrothorax CD3+, CD3+CD4+ T, CD3+CD8+ T, CD19+CD5+ B cells, and CD3−CD16/56+ NK cells were characterized by flow cytometry, and the ratios of CD4+ to CD8+ T cells were calculated in individual groups of subjects. Data shown are the mean values of individual subjects. a–c The numbers of CD3+, CD3+CD4+, and CD3+CD8+ T cells. d The ratios of CD4+ to CD8+ T cells. e, f The numbers of CD19+CD5+ B cells and CD3−CD16/56+ NK cells. The horizontal lines show the median values of individual groups. HCs healthy controls.