title: Quantitation of T lymphocytes in posttransplant transbronchial biopsies.
abstract: The diagnostic role of immunohistochemical staining for T lymphocytes in grading acute airway rejection has not been fully explored. We examined 136 transbronchial biopsies from 52 lung transplant patients and 9 nontransplant controls. Transplant rejection was based on histologic assessment of perivascular (A) and bronchiolar (B) infiltrates. The clinical indication for the 136 allograft biopsies was routine surveillance (n = 72), decreased pulmonary function, rule out rejection (n = 36), suspect infection (n = 16), rule out obliterative bronchiolitis (n = 6), and persistent postoperative graft failure (n = 6). T lymphocytes were counted in bronchial mucosa per 100 bronchial epithelial cells, and in alveolar walls per square millimeters, after immunohistochemical staining with anti-CD3, CD4, and CD8. In controls, the mean alveolar wall CD3 cell count was 45 per square millimeter (95% confidence intervals, 30-52 per square millimeter) and the mean CD8 count was 15 per square millimeter (2-20 per square millimeter). In surveillance and negative patient biopsies, alveolar wall CD8 counts were significantly greater than controls (P = .03 and .02, respectively). Mean alveolar wall CD3 counts were significantly higher in type A rejection (88.7 +/- 12.9) than controls and negative biopsies (42 +/- 5.3, P < .001), but there was no difference compared to infections (119.7 +/- 22, P > .5). Mucosal CD3 cell counts were significantly higher in type B rejection (16.1 +/- 2.5) than controls and negative biopsies (1.5 +/- 0.4, P < .001), and also higher than infections (3.9 +/- 1.1, P < .001). In 7% of biopsies, T-cell staining identified perivascular circumferential infiltrates that were difficult to identify on routine stains, and in an additional 9% minor changes in grading were made after reviewing T-cell markers. Immunohistochemical staining may help in identifying perivascular infiltrates and demonstrates increased intraepithelial T-cells even in low-grade type B rejection. Type B rejection as assessed quantitatively is more specific than type A rejection in comparison to infection.
authors.affiliation: Department of Genitourinary Pathology, Armed Forces Institute of Pathology, Washington, DC 20306, USA.
authors.forename: Fabio
authors.initials: F
authors.lastname: Tavora
authors.forename: Cinthia
authors.initials: C
authors.lastname: Drachenberg
authors.forename: Aldo
authors.initials: A
authors.lastname: Iacono
authors.forename: Allen P
authors.initials: AP
authors.lastname: Burke
mesh_terms: D001706:Biopsy; D001980:Bronchi / Q000276:immunology*; D017252:CD3 Complex / Q000276:immunology; D015704:CD4 Antigens / Q000276:immunology; D016827:CD8 Antigens / Q000276:immunology; D005260:Female; D006084:Graft Rejection / Q000276:immunology*; D006801:Humans; D007150:Immunohistochemistry; D016040:Lung Transplantation / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D020545:Respiratory Mucosa / Q000276:immunology; D012141:Respiratory Tract Infections / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D017252:CD3 Complex; D015704:CD4 Antigens; D016827:CD8 Antigens