Two-site enzyme immunoassay of CD4 and CD8 molecules on the surface of T lymphocytes from healthy subjects and HIV-1-infected patients

Abstract

A highly sensitive two-site enzyme immunoassay (Capcellia) was developed to determine the concentration of CD4 and CD8 molecules expressed on the surface of human T lymphocytes. This assay, performed in one step (20 min), involves the specific immunocapture of T lymphocytes and reaction of the CD4 or CD8 molecules with an enzyme-labeled monoclonal antibody (mAb). The results were expressed as molar concentrations of the T-cell markers on the basis of results obtained with calibrated CD4 and CD8 standards. The assay was sensitive enough to detect 0.4 pmol/L CD4 or 0.8 pmol/L CD8, which corresponded to approximately 20 x 10(6) CD4+ or CD8+ T cells per liter of blood. Mean concentrations in healthy adults were 17.2 pmol/L for CD4 and 22.1 pmol/L for CD8. The CD4 concentration was < 8 pmol/L in 50% of HIV-1-infected patients and in 95% of AIDS patients. Given the epitopic specificity of the mAb to CD4 we used, these values correspond to the concentration of CD4 molecules free of envelope glycoprotein (gp)120.

Evaluation of a quantitative determination of CD4 and CD8 molecules as an alternative to CD4 + and CD8 + T lymphocyte counts in Africans

“…The coefficient of correlation was similar to that previously reported in a Caucasian population (Franke et al 1994). Carrière et al (1994) suggested an equivalence between pmol and number of cells: for CD4, 1 pmol ϭ 50 ϫ 10 6 cells/l and for CD8, 1 pmol/l ϭ 25 cells ϫ 10 6 /l. The sensitivity of the Capcellia assay is 0.9 pmol/l, which corresponds to 0.045 ϫ10 6 /l CD4 T lymphoctes.…”

“…More and more people present with HIV infection in the developing world, so a less expensive method for their monitoring is needed. Alternative methods for the enumeration of CD4 T lymphocytes have been developed and evaluated (Carrière et al 1994;Nicholson Pinilla Moraza et al 1997). We compared concentrations of CD4 and CD8 molecules in circulating T cells given by the Capcellia assay (Carrière et al 1994) to CD4 ϩ and CD8 ϩ T lymphocyte numbers provided by cytofluorometry and haematology analysers.To compare the two methods within a wide range of absolute CD4 ϩ T lymphocyte counts, samples were collected from an AIDS clinic, a TB clinic and from healthy blood bank donors.…”

“…Alternatively to this reference assay, the commercially available Capcellia CD4/CD8 assay (Sanofi Diagnostics Pasteur, Marnes-la-Coquette, France) uses a one-step enzyme-linked immunoassay format to provide quantitative determination of CD4 and CD8 molecules (Carrière et al 1994). To evaluate the usefulness of the Capcellia assay in comparison to flow cytometry or haematology, blood samples were collected from 83 adult donors, HIV-1 infected or not, and evaluated by both assays.…”

“…Alternatively to this reference assay, the commercially available Capcellia CD4/CD8 assay (Sanofi Diagnostics Pasteur, Marnes‐la‐Coquette, France) uses a one‐step enzyme‐linked immunoassay format to provide quantitative determination of CD4 and CD8 molecules ( Carrière et al . 1994 ).…”

Development and optimization of a double antibody sandwich ELISA for the detection of goose T cell surface CD8α molecule

“…Considering that both CD8αα and CD8αβ contain the CD8α chain, CD8α was chosen for the detection of CD8 molecules in this study. A double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) has previously been developed for the detection of human CD8 molecules (Carriere et al 1994) and is operational in distinguishing between healthy subjects and viral-infected patients. Recently, ELISA kits have emerged for using the recognition of goose CD8 (MyBioSource, Cat.…”