DETERMINATION OF CD4- A COMPARATIVE-STUDY WITH FLOW-CYTOMETRY AND THEIMMUNOALKALINE PHOSPHATASE METHOD( AND CD8+ LYMPHOCYTES WITH THE CYTOSPHERE ASSAY )

The proportion and absolute numbers of CD4(+) and CD8(+) lymphocytes i n peripheral blood were determined using a new manual method, the cyto sphere assay (CA). This method uses small latex beads coated with mono clonal antibodies directed against the CD4 and CDS receptors, respecti vely. The CA was compared with two other methods for determination of T lymphocyte subsets, flow cytometry (FC) and the immunoalkaline phosp hatase (IA) method, by testing HIV-seropositive and HIV-seronegative s amples from Denmark (44) and Ivory Coast (79). For HIV-seropositive sa mples, both the proportion and the absolute number of CD4(+) lymphocyt es determined by CA showed a good correlation with results obtained by FC (correlation coefficients were 0.92 and 0.74 in Denmark and The Iv ory Coast, respectively) and IA (correlation coefficients were 0.94 an d 0.66 in Denmark and The Ivory Coast, respectively). However, for HIV -seronegative samples the corresponding correlation coefficients were low. CD4% determinations deviated more from FC counts at higher CD4 co unts than at lower levels for both seronegative and seropositive indiv iduals. In conclusion, the CA performed best for samples from HN-infec ted individuals. Before a more general utilization of the method, it i s necessary to improve its repeatability and standardize its performan ce at all levels of CD4(+) T cells. (C) 1995 Academic Press, Inc.