Selective activation of circulating CD4+ lymphocytes in severe adult atopic dermatitis

An analysis of peripheral blood lymphocyte subsets and their expression of activation markers was performed using flow cytometry in 12 adult patients with severe atopic dermatitis, and compared with 14 normal individuals. Repeated measurements were made over an 8-week period during which disease activity was also assessed. Increased percentages of activated and unactivated CD4+ lymphocytes, and decreased percentages of CD8+ cells were observed in atopic dermatitis. Increasing disease activity was associated with an increase in the proportion of activated and unactivated CD4+ lymphocytes and a fall in the proportion of CD8+ cells. This study demonstrates that in adults with severe atopic dermatitis, increasing disease activity is associated with selective activation of CD4+ lymphocytes and a relative expansion of the CD4+ cell subset.