Distribution of lymphocyte subsets in healthy human immunodeficiency virus-negative adult ethiopians from two geographic locales

Immunological values for 562 factory workers from Wonji, Ethiopia, a sugar estate 114 km southeast of the capital city, Addis Ababa, Ethiopia, were co mpared to values for 218 subjects from Akaki, Ethiopia, a suburb of Addis A baba, for whom partial data were previously published. The following marker s were measured: lymphocytes, T cells, B cells, NK cells, CD4(+) T cells, a nd CD8(+) T cells. A more in depth comparison was also made between Akaki a nd Wonji subjects. For this purpose, various differentiation and activation marker (CD45RA, CD27, HLA-DR, and CD38) expressions on CD4(+) and CD8(+) T cells were studied in 60 male, human immunodeficiency virus-negative subje cts (30 from each site). Data were also compared with Dutch blood donor con trol values. The results confirmed that Ethiopians have significantly decre ased CD4(+) T-cell counts and highly activated immune status, independent o f the geographic locale studied. They also showed that male subjects from A kaki have significantly higher CD8(+) T.-cell counts, resulting in a propor tional increase in each of the CD8(+) T-cell compartments studied: naive (C D45RA(+)CD27(+)), memory (CD45RA(-)CD27(+)), cytotoxic effector (CD45RA(+)C D27(-)), memory/effector (CD45RA(-)CD27(-)), activated (HLA-DR(+)CD38(+)), and resting (HLA-DR(-)CD38(-)). No expansion of a specific functional subse t was observed. Endemic infection or higher immune activation is thus not a likely cause of the higher CD8 counts in the Akaki subjects. The data conf irm and extend earlier observations and suggest that, although most lymphoc yte subsets are comparable between the two geographical locales, there are also differences. Thus, care should be taken in extrapolating immunological reference values from one population group to another.