A RAPID MANUAL METHOD FOR CD4-CELL QUANTITATION FOR USE IN DEVELOPING-COUNTRIES( T)

Objective: To evaluate a manual method (Cytosphere) for quantifying CD 4+ T-cell numbers. Design: Cross-sectional study of HIV-1-seronegative and HIV-1-seropositive individuals evaluated for absolute CD4 counts by both standardized flow cytometric measurements and manual Cytospher e technology using a hemacytometer. Setting: University research hospi tals in both the United States and Africa. Patients, participants: Blo od specimens from 382 patients were evaluated. These were broken down into 294 samples obtained from HIV-1-seropositive patients and 88 samp les obtained from HIV-1-seronegative patients. Interventions: None. Ou tcome measured: Absolute CD4 cell number. Results: Evaluation of sampl es obtained from HIV-1 patients in both the United States and Africa d emonstrated an overall correlation of the Cytosphere assay with flow c ytometry of 0.912 (95% confidence interval, 0.895-0.928; P < 0.001). W hen samples were stratified based on CD4+ T-cell counts determined by flow cytometry, the Cytosphere assay had a 96% predictive value for co rrectly identifying individuals with CD4 T-cell counts > 200 x 10(6)/l and a 92% predictive value for correctly identifying individuals with CD4 T-cell counts < 200 x 10(6)/l. Conclusions: This assay appears to have the potential for the quantitation of CD4 cells in the limited l aboratory facilities in developing countries and to have a strong corr elation with standard flow Cytometric technology.