title: Decreased expression of T-cell costimulatory molecule CD28 on CD4 and CD8 T cells of mexican patients with pulmonary tuberculosis.
abstract: Patients with tuberculosis frequently develop anergy, a state of T-cell hyporesponsiveness in which defective T-cell costimulation could be a factor. To know if the expression of T-cell costimulatory molecules was altered in tuberculosis, we analyzed the peripheral blood T-cell phenotype of 23 Mexican patients with pulmonary tuberculosis. There was severe CD4 (P < .001) and CD8 (P < .01) lymphopenia and upregulation of costimulatory molecule CD30 on CD4 and CD8 T cells (P < .05); this increase was higher in relapsing tuberculosis. The main finding was severe downregulation of the major costimulatory molecule CD28 on both CD8 and CD4 T cells (P < .001). Depletion of the CD4/CD28 subset, a hitherto undescribed finding, is relevant because CD4 T cells constitute the main arm of the cell-mediated antimycobacterial immune response.
authors.affiliation: Facultad de Farmacia, Universidad Autonoma del Estado de Morelos, 62209 Morelos, Mexico.
authors.forename: German
authors.initials: G
authors.lastname: Bernal-Fernandez
authors.forename: Patricia
authors.initials: P
authors.lastname: Espinosa-Cueto
authors.forename: Rosario
authors.initials: R
authors.lastname: Leyva-Meza
authors.forename: Nathalie
authors.initials: N
authors.lastname: Mancilla
authors.forename: Raul
authors.initials: R
authors.lastname: Mancilla