title: Expansion of CD11abright cells in CD8+CD45RA+ from HIV-infected patients: a new early marker for disease progression?
abstract: CD8+CD45RA+ T lymphocytes present two distinct subpopulations expressing the CD11a molecule (LFA-1 alpha chain) with different intensity. CD11adim cells represent the unprimed population within the CD8+CD45RA+ subset, whereas CD11abright cells are activated and may be considered as memory lymphocytes. The aim of this study was to analyze the expression of CD11a and CD18 within the CD8+CD45RA+ population in young HIV-infected individuals at different stages of disease as a marker of activation and of disease progression. Blood cells from 82 HIV-infected individuals and 23 age-matched healthy controls were stained with unconjugated CD11a, CD18, PE-goat F(ab')2 anti-mouse, FITC-CD45RA, and TRI-Color CD8. Quantitative analysis for three-color immunofluorescence was carried out by flow cytometry. HIV+ subjects were subdivided into three groups according to their CD4+ cell number (group A, CD4+ cells > 500/microliters [20 subjects], group B, CD4+ cells between 500 and 200/microliters [36 subjects], and group C, CD4+ lymphocytes < 200/microliters [26 subjects]). We found a significant increase of CD11abright in the CD8+CD45RA+ subpopulation throughout the progression of the disease. The CD11abright percentage of positivity (mean) within the CD8+CD45RA+ subpopulation was 31% in healthy donors, 51% in group A, 52% in group B, and 68% in group C. CD11abright expression was closely related to CD18bright (p < 0.001), but not to CD38. The relative increase of CD11a and CD18 expression in CD8+CD45RA+ T lymphocytes parallels the decrease of CD4+ cells and the progression of disease: an inverse correlation between the percentages of CD4+ cells/microliter and CD8+CD45RA+CD11abright cells (p < 0.001) and a direct correlation between the number of CD4+ lymphocytes per microliter and both the number of CD8+CD45RA+CD11adim cells (p < 0.001) and the number of CD8+CD45RA+CD11abright (p = 0.002) was observed. The relative increase of CD8+CD45RA+CD11abright cells may represent an additional marker for monitoring HIV-induced immunodeficiency.
authors.affiliation: Department of Clinical Medicine, University of Rome, La Sapienza, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Scala
authors.forename: I J
authors.initials: IJ
authors.lastname: Ansotegui
authors.forename: B
authors.initials: B
authors.lastname: Bellioni
authors.forename: E C
authors.initials: EC
authors.lastname: Guerra
authors.forename: F
authors.initials: F
authors.lastname: Aiuti
authors.forename: R
authors.initials: R
authors.lastname: Paganelli
mesh_terms: D000328:Adult; D015415:Biomarkers; D018845:CD11 Antigens / Q000378:metabolism*; D018821:CD18 Antigens / Q000378:metabolism*; D016516:CD4-CD8 Ratio; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D018450:Disease Progression; D005260:Female; D015658:HIV Infections / Q000097:blood / Q000276:immunology*; D006801:Humans; D017493:Leukocyte Common Antigens / Q000276:immunology*; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged
chemical_list: D015415:Biomarkers; D018845:CD11 Antigens; D018821:CD18 Antigens; D017493:Leukocyte Common Antigens