title: An Evaluation of the Spontaneous Proliferation of Peripheral Blood Mononuclear Cells in HTLV-1-Infected Individuals Using Flow Cytometry.
abstract: The spontaneous proliferation of peripheral blood mononuclear cells (PBMCs) is a hallmark of the human T-lymphotropic virus (HTLV) type-1. Cell proliferation is usually measured using a [(3)H]thymidine incorporation assay. This study aims to quantify the spontaneous proliferation of PBMCs using flow cytometry. PBMCs were cultured for 24 to 120 hours in the presence of 5,6-carboxyfluorescein diacetate succinimidyl ester (CFSE). For comparison, PBMCs were also cultured with [(3)H]thymidine. The cutoff values for spontaneous proliferation were >0.06 for the division index and >5.8% for the percentage of divided cells. Sixty-two percent of HTLV-1-infected individuals presented spontaneous proliferation of PBMCs, which was detected in the first 24 hours. Moreover, proliferation was detected in CD4(+) and CD8(+) T-lymphocyte subsets. A positive correlation was found between the division index and [(3)H]thymidine incorporation. This method may prove useful to better understand the phenomenon of spontaneous proliferation of PBMC of patients infected with HTLV-1.
authors.affiliation: Advanced Laboratory of Public Health, Gonçalo Moniz Center, Oswaldo Cruz Foundation, 40296-710 Salvador, BA, Brazil.
authors.forename: Lorena Ana
authors.initials: LA
authors.lastname: Pinto
authors.forename: Bernardo
authors.initials: B
authors.lastname: Galvão Castro
authors.forename: Milena Botelho Pereira
authors.initials: MB
authors.lastname: Soares
authors.forename: Maria Fernanda Rios
authors.initials: MF
authors.lastname: Grassi