CD8(+) T cell populations in common variable immunodeficiency

In a subgroup of CVID T cell abnormalities have been reported. Peripheral b lood T lymphocytes from patients with common variable immunodeficiency (CVI D) and blood donors were examined for expression of CD8 alpha, CD8 beta and CD28. In CVID, three CD8(+) T cells could be defined: CD8 beta(high)CD28() (expressing CD8 beta at a high median fluorescence intensity), CD8 beta(l ow)CD28(+) and CD8 beta(low) CD28(-) cells. The number of CD8 beta(low) cel ls was markedly increased compared to blood donors. After activation, CD8 b eta(high)CD28(+) cells from cord blood differentiated into CD8 beta(low) CD 28(-)cells. Therefore, CD8 beta(low) cells are induced by activation even i n normal donors, but may reflect inflammatory activity in CVID.