Normal plasmacytoid DC numbers and dendritic cell IFN production in APECED. (A) Percentages of plasmacytoid DCs (pDCs) among PBMCs in APECED and control groups (P = .079, t test). (B) Expression of type I IFN genes after plasmacytoid DC stimulation for 6 hours with live influenza virus (left panel) or 2.5 μM CpG (right panel) in IFN-α–positive APECED (Ab⁺) or control persons (Ctrl). (C) IRF3 and IRF7 expression in stimulated plasmacytoid DCs from APECED or control individuals. (D) Type I IFN gene expression was studied after 18 hours of stimulation of monocyte-derived DCs from APECED patients (Ab⁺) and healthy controls (Ctrl) with 25 μg/mL of poly(I:C).