Myeloid dendritic cells type 2 in allergic asthma

BACKGROUND: Myeloid dendritic cells type 2 (mDC2s) are a new subtype of DCs identified in both the circulation and the lung and suggested to have a role in allergic asthma. METHODS: Circulating mDC2s were enumerated in 19 healthy, 18 atopic nonasthmatic, 18 mild atopic asthmatic, and 16 moderate/severe atopic asthmatic subjects using flow cytometry. RESULTS: The number of circulating mDC2s was significantly lower in atopic subjects compared with healthy controls and in asthmatic subjects compared with nonasthmatic subjects. There was a trend toward lower levels of circulating mDC2s with increasing allergy and asthma severity. The largest differences were seen in moderate/severe atopic asthmatics being 430.78 ± 48.91/ml compared with healthy controls being 767.05 ± 101.64/ml (P < 0.05). CONCLUSIONS: Circulating mDC2s are lower in atopic and asthmatic subjects, which suggests that these cells efflux from the blood into the airways in patients with allergic disease.