The dysfunction of peripheral blood dendritic cells in patients with mixed connective tissue disease

The morphological findings and functions of peripheral blood dendritic cells (DC) from patients with mixed connective tissue disease (MCTD) were compared with those of DC from normal subjects. DC from both groups possessed typical dendritic processes and showed HLA-DR antigens and C3bi receptor. The autologous mixed lymphocyte reaction (MLR) and autologous concanavalin A (Con A)-induced T cell proliferation using DC as stimulating cells and accessory cells were significantly depressed in patients with MCTD. In the allogeneic MLR and allogeneic Con A responses, DC from patients with MCTD were poorer stimulating cells and accessory cells. The dysfunction of DC also, as one of the various immune abnormalities, must play a role in the appearance of clinical features.