Immunopathology of Postprimary Tuberculosis: Increased T-Regulatory Cells and DEC-205-Positive Foamy Macrophages in Cavitary Lesions
Figure 2
Lipid pneumonia. (a) Alveoli are filled with macrophages and the alveolar walls have high numbers of lymphocytes, 100x. (b) Macrophages in the lipid pneumonia have a foamy appearance, 400x. (c) The cells in the alveoli may undergo necrosis to produce a homogenous appearance, 100x. (d) Relatively few CD4+ cells are present in lipid pneumonia, 400x. (e) Abundant CD8+ cells are noted in the alveoli as well as in the alveolar walls, 400x. (f) Foamy cells stain strongly with the CD68 marker. (g) Foamy macrophages in the lipid pneumonia are frequently positive for the dendritic cell marker DEC-205, 400x. The insert shows a detailed image of a DEC-205-positive macrophage. (h) T-regulatory cells were observed in regions of lipid pneumonia (arrow), 400x. (i) The CD31 stain highlights the disrupted lung architecture, 100x.
