CD30 expression on circulating memory CD4(+) T cells as a Th2-dominated situation in patients with atopic dermatitis

Th2 clones have been reported to express CD30 preferentially, but whether T cells producing Th2-type cytokines may favor CD30 expression in the in who state remains unknown. We investigated the expression of CD30 on circulati ng T cells in atopic dermatitis (AD) as a Th2-dominated disorder. Periphera l blood mononuclear cells were prepared from 51 AD patients and 14 nonatopi c controls, and their phenotypes were analyzed with flow cytometry. Cytokin e production by stimulated CD4(+) T cells was also assessed by the single-c ell-staining method. Flow cytometric analysis clearly revealed that CD30(+) T cells were identifiable in the blood of AD patients with greater frequen cy compared to controls. The important finding was that CD30 expression was restricted to a small but substantial population of memory (CD45RO(+)) CD4 (+) T cells, but not CD8(+) ones. In AD patients, it was demonstrated that the percentages of CD30(+) cells within CD45RO(+) CD4(+) T cells correlated well with the disease severity, serum IgE levels, peripheral eosinophil co unts, and tendency toward Th2-dominant cytokine pattern as determined by th e ratio of interleukin-4 to interferon-gamma production. This study suggest s that CD30 expression in circulating T cells might serve as an in vivo mar ker for the Th2-dominated condition.