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

In the developed word,monitoring HIV-infected patients is routinely determi ned by CD4 + T lymphocyte absolute counts. The reference procedure, flow cy tometry, is expensive, requires sophisticated instrumentation and operators with specific training. Due to these limitations, CD4 counting is often un available in developing countries. The Capcellia assay is an enzyme-linked immunoassay for quantitative determination of CD4 and CD8 molecules. We eva luated this method in West Africa on blood samples collected from 39 HIV-un infected and 44 HIV-infected adult subjects. CD4 concentration ranges were determined according to the clinical stages of the disease. We then studied the relationship between the two methods in the HIV-infected patients. The Spearman's rank correlation was 0.61 (95 % confidence interval: 0.38-0.76, P < 0.0001). Nevertheless, determination of limits of agreement revealed d iscrepancies between the two methods, especially for CD4 counts > 0.4 X 10( 9)/l, which are discussed. We conclude that the Capcellia assay is a conven ient means to determine the immunodepression level where flow cytometric in strumentation is unavailable, and can be complementary to CD4 T lymphocyte enumeration.