title: Immunopathology of postprimary tuberculosis: increased T-regulatory cells and DEC-205-positive foamy macrophages in cavitary lesions.
abstract: Postprimary tuberculosis occurs in immunocompetent people infected with Mycobacterium tuberculosis. It is restricted to the lung and accounts for 80% of cases and nearly 100% of transmission. Little is known about the immunopathology of postprimary tuberculosis due to limited availability of specimens. Tissues from 30 autopsy cases of pulmonary tuberculosis were located. Sections of characteristic lesions of caseating granulomas, lipid pneumonia, and cavitary stages of postprimary disease were selected for immunohistochemical studies of macrophages, lymphocytes, endothelial cells, and mycobacterial antigens. A higher percentage of cells in lipid pneumonia (36.1%) and cavitary lesions (27.8%) were positive for the dendritic cell marker DEC-205, compared to granulomas (9.0%, P < .05). Cavities contained significantly more T-regulatory cells (14.8%) than found in lipid pneumonia (5.2%) or granulomas (4.8%). Distribution of the immune cell types may contribute to the inability of the immune system to eradicate tuberculosis.
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Texas Medical School at Houston, 6431 Fannin, MSB 2.136, Houston, TX 77030, USA.
authors.forename: Kerry J
authors.initials: KJ
authors.lastname: Welsh
authors.forename: Semyon A
authors.initials: SA
authors.lastname: Risin
authors.forename: Jeffrey K
authors.initials: JK
authors.lastname: Actor
authors.forename: Robert L
authors.initials: RL
authors.lastname: Hunter
mesh_terms: D000942:Antigens, Bacterial / Q000032:analysis / Q000276:immunology; D015703:Antigens, CD / Q000032:analysis / Q000276:immunology; D001344:Autopsy; D015415:Biomarkers / Q000032:analysis; D003713:Dendritic Cells / Q000276:immunology / Q000473:pathology; D005487:Foam Cells / Q000276:immunology / Q000473:pathology; D006099:Granuloma / Q000276:immunology / Q000382:microbiology / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D037181:Lectins, C-Type / Q000032:analysis / Q000276:immunology; D008168:Lung / Q000276:immunology / Q000382:microbiology / Q000473:pathology; D015778:Minor Histocompatibility Antigens; D009169:Mycobacterium tuberculosis / Q000276:immunology; D009928:Organ Specificity; D011017:Pneumonia, Lipid / Q000276:immunology / Q000382:microbiology / Q000473:pathology; D011956:Receptors, Cell Surface / Q000032:analysis / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology / Q000473:pathology; D014397:Tuberculosis, Pulmonary / Q000276:immunology / Q000382:microbiology / Q000473:pathology
chemical_list: D000942:Antigens, Bacterial; D015703:Antigens, CD; D015415:Biomarkers; C093569:DEC-205 receptor; D037181:Lectins, C-Type; D015778:Minor Histocompatibility Antigens; D011956:Receptors, Cell Surface