O19 - Changes in the balance between myeloid (mDC) and plasmacytoid (pDC) cell numbers in peripheral blood during childhood

Background Dendritic cells (DCs) are the most potent antigenpresenting cells, having an important role in linking innate and adaptive immunity. DCs are also critical mediators of immune tolerance and anergy, depending on the type of antigen they encounter. Peripheral blood DCs represent only the 0.1–1% of mononuclear cells and, based on their lineage origins, they can be divided into two major subsets, plasmacytoid DCs (pDCs) and myeloid DCs (mDCs). Although, the total number of all blood circulating lymphocyte subpopulations in children declines with age, previous studies performed on age-related DC changes have shown controversial results [1-4].