Table of Contents
ISRN Oncology
Volume 2011, Article ID 326719, 6 pages
Research Article

An Evaluation of the Spontaneous Proliferation of Peripheral Blood Mononuclear Cells in HTLV-1-Infected Individuals Using Flow Cytometry

1Advanced Laboratory of Public Health, Gonçalo Moniz Center, Oswaldo Cruz Foundation, 40296-710 Salvador, BA, Brazil
2HTLV Center, Bahiana School of Medicine and Public Health (EBMSP), 40290-000 Salvador, BA, Brazil
3Laboratory of Tissue Engineering and Immunopharmacology, Gonçalo Moniz Center, Oswaldo Cruz Foundation, 40296-710 Salvador, BA, Brazil
4Center of Biotechnology and Cell Therapy, São Rafael Hospital, 41250-390 Salvador, BA, Brazil

Received 7 August 2011; Accepted 12 September 2011

Academic Editors: Y. Akiyama and S. Holdenrieder

Copyright © 2011 Lorena Ana Pinto et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


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 [3H]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 [3H]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 [3H]thymidine incorporation. This method may prove useful to better understand the phenomenon of spontaneous proliferation of PBMC of patients infected with HTLV-1.