Altered peripheral invariant natural killer T cells in atopic dermatitis.

BACKGROUND: Conflicting data exist on the number of invariant NKT (iNKT) cells in atopic dermatitis (AD); furthermore, no data have been published on their functional capacity. METHODS: The frequency and number of circulating CD3+6B11+ iNKT cells and their CD4+ and CD4- subpopulations were evaluated in peripheral blood obtained from 41 patients with AD by four-color flow cytometry. Likewise, functional properties of iNKT cells were measured by five-color intracellular cytokine staining. RESULTS: The number and percentage of total iNKT cells and their CD4/CD8 subpopulations were significantly lower than the controls. Of further importance, the CD4-CD8- (double negative, DN) iNKT subgroup showed the strongest positive correlation with total iNKT cells. In addition, the DN subgroup exhibited the most pronounced functional alteration with significantly decreased levels of intracellular IFNγ and significantly increased levels of intracellular IL-4 in AD patients compared with the controls. CONCLUSION: The significantly altered number and cytokine production of iNKT cells from AD patients suggests that these cells may play an important role in the pathogenesis of AD.