Plasmacytoid dendritic cells (pDC) in mononuclear cells from human mesenteric lymph nodes (MLN) and peripheral blood (PB). (a) Mononuclear cells isolated from MLN or PB were analysed by flow cytometry. After exclusion of CD14+, CD19+ and dead cells, pDC were defined as CD11c– and BDCA-2+ cells. (b) Proportions of pDC within mononuclear cells from MLN of patients with and without inflammatory bowel disease (IBD; n = 12, six non-IBD, six IBD) and PB (n = 10, all from IBD patients) as well as from control PB (n = 10). **P < 0·01, ***P < 0·001; Mann–Whitney U-test.