Increased levels of circulating endothelial progenitor cells in human T-cell lymphotropic virus type I carriers
Ana Luisa L Pedroso Meireles1, Abrahão Elias Hallack Neto, Renata de Oliveira Costa
1Departamento de Hematologia, Faculdade de Medicina da Universidade de São Paulo (USP), Hospital das Clínicas, São Paulo, SP, Brazil.
Background And Aims:
HTLV-I-transformed T cells secrete biologically active forms of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (b-FGF). In addition, HTLV-I-transformed cells have a high capacity of adhesion to endothelial cells.
Methods:
We measured the circulating endothelial progenitor cells (EPCs) and mature endothelial cells (MECs) by flow cytometry in 27 HTLV-I carriers in comparison to 30 healthy, age- and gender-matched subjects. All subjects had HTLV-I positivity confirmed by Western blot and/or polymerase chain reaction (PCR). The numbers of different subpopulations of EPCs and MECSs were evaluated by four-color flow cytometry using a panel of monoclonal antibodies. All reactions were done in duplicate to confirm reproducibility of the results.
Results:
The median age of all 27 HTLV-I carriers enrolled in this study was 45 years (range: 27-65 years); 11 (41%) were male and 16 (59%) were female. The median age of the 30 healthy subjects in the control group was 45.5 years (range: 20-63 years); 11 (36.6%) were male and 19 (63.4%) were female. The number of EPCs was significantly higher in HTLV-I carriers (median 0.8288 cells/μL, range: 0.0920-3.3176 cells/μL) as compared to control group (median 0.4905 cells/μL, range: 0.0000-1.5660 cells/μL) (p = 0.035). In contrast, the median of the MECs in the HTLV-I carriers was 0.6380 cells/μL (range: 0.0473-5.7618 cells/μL) and 0.4950 cells/μL (range: 0.0000-4.0896 cells/μL) in the control group, with no statistical difference (p = 0.697).
Conclusions:
We demonstrated that EPCs, but not MECs, are increased in the peripheral blood of HTLV-I carriers.
