OBJECTIVEAnalyzing the relationships between peripheral blood CD4+ CD25hi regulatory T (Treg) cells and peripheral blood immune status or plasma HIV-lviral load in HIV-infected individuals,so as to determine whether Treg were related to the progression of HIV-infected disease.

METHODS116 HIV-infected patients in different stages and 21 healthy control individuals were included in this study. The CD4+ and CD8+ T cell counts were determined by a standard 4-color flow cytometry technique. The Treg cells were examined with 3-color immune staining flow cytometry. The plasma HIV-1 viral load was detected by real time PCR.

RESULTSThe frequencies of Treg cells decreased in HIV-infected individuals with high CD4+ T cell counts( > 300/microl) compared with normal controls. With the progression of disease the frequencies of Treg cells were raised gradually, until were increased in HIV-infected individuals with low levels of CD4+ T cell counts ( < 100/microl). In addition, the frequencies of Treg cells were inversely related to CD4+ T cell counts and CD4+ /CD8+ ratio, data showed a statistically significant (respectively, r = -0.564, P < 0.001; r = -0.377, P < 0.001). Furthermore, the proportions of Treg cells were closely related to plasma HIV-1 RNA viral load (r = 0.514, P < 0.001).

CONCLUSIONCD4 CD25hi Treg cells should be a kind of important cells participating the immunopathogenesis of AIDS. It may play different roles in different stages of HIV-infected disease. The exact mechanism of Treg cells in the progression of the HIV-infected disease needs to be investigate further.

Adult ; Case-Control Studies ; Cells, Cultured ; Disease Progression ; Female ; HIV Infections ; immunology ; pathology ; virology ; HIV-1 ; genetics ; immunology ; isolation & purification ; Humans ; Interleukin-2 Receptor alpha Subunit ; immunology ; Male ; Middle Aged ; T-Lymphocytes, Regulatory ; immunology ; Viral Load