Background:  To date, the immunophenotyping of cluster of differentiation antigens (CD) relies heavily on flow cytometry, which allows estimation of only 3 markers in a given assay. What is clearly lacking is a cumulative analysis of the whole spectrum of CD markers on a protein array platform. As both the quality and numbers of CD4⁺ and CD8⁺ T cells are crucial in HIV disease, the main objective was to use a novel approach to examine CD antigens expressed on these 2 cell types to distinguish various HIV disease groups.

Methods:  We used Dot Scan Antibody Microarray, a new technology that enables immunophenotyping of CD antigens in a cumulative fashion. Fresh CD4⁺ and CD8⁺ T cells obtained from whole peripheral blood mononuclear cells (PBMC) by magnetic bead separation were captured on a slide coated with 146 CD markers. The read out was obtained using a scanner. Here, we simultaneously compared CD antigens on fresh CD4⁺ and CD8⁺ T cells from HIV^–individuals (n = 5), HIV⁺ individuals controlling viremia naturally (>20 years of infection) (n = 4), patients controlling plasma viremia with HAART (BDL ≤50 copies/mL plasma) (n = 10), and patients experiencing viremia during HAART (n = 6). One-way analysis of variance was used for deriving statistically significant antibody rankings between HIV groups and p values were adjusted using Holme’s method.

Results:  Our unique approach of simultaneously comparing both CD4⁺ and CD8⁺ T-cells groups has provided a wholesome discrimination between CD markers on the cell surface between various HIV disease groups. Pairwise comparisons between groups showed statistically significant differences in the CD markers on both CD4⁺ and CD8⁺ T cells. Of 16 statistically significant markers observed, 6 are cell adhesion molecules, 8 are related to T-cell activation, apoptosis, and cell senescence, and 2 are IL-2 and T-cell receptor molecules.

Conclusions:  These analyses are unique in showing 2 new T-cells markers (11c and TCRα/β) previously not known for HIV disease. Although both CD4⁺ and CD8⁺ T cells showed good predictive value, the CD8⁺ T cells appear to be more distinguishable, which has remained unknown because these cell types have never been analyzed simultaneously in the context of HIV in an array-like fashion. Together, these analyses can be of immense value in predicting immune status of HIV patients.