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An imbalance of interferon-gamma (IFN-γ)-bearing CD4+ T (Th1) cells in the pathogenesis of AD is well recognized; however, a possible role in AD for CD8+ T cells secreting Th1-like cytokines (Tc1) has not been properly addressed. In this study, two- and three-colour FACS analysis allowed us to discriminate the Th1 from the Tc1 subset. AD patients had half the number of IFN-γ-producing circulating T cells (P < 0·005; 13·6 ± 1·9% (mean ± s.d.)) compared with normal donors (25·0 ± 2·4%). Specifically, both Th1 (4·8 ± 0·7%) and Tc1 (8·1 ± 1·1%) cells in AD were decreased compared with Th1 (8·8 ± 0·8%) and Tc1 (15·0 ± 1·5%) cells in controls. Moreover, at the mRNA level, the ratios of IFN-γ/IL-4 and IFN-γ/IL-10 were lower in cells from AD patients compared with controls. In conclusion, the decrease of IFN-γ-producing T lymphocytes in AD is due to a reduction in both Th1 and Tc1 IFN-γ-secreting cells; this may not only contribute to the over-production of IgE, but also explain the high incidence of cutaneous infections observed in AD patients.