Morphological diversity of DRC-1 positive cells: human follicular dendritic cells and their relatives

Follicular dendritic cells (FDC) and their relatives of the human tonsils and lymph nodes were immunoelectron microscopically analyzed with a monoclonal antibody DRC-1 (DAKO) in a combination with an enzymatic isolation technique. DRC-1+ cells were largely grouped into three type A (large mono- to multinucleated, sea anemone-fashioned, bearing labyrinth structures, in germinal center), type B (oligodendritic or stellate, medium-sized, in the corona and the primary follicle) and type C (individually located, medium-sized. lymphoid cell-fashioned, outside follicles). Type C were found in hyperplastic lymphoid tissue as well as in some granulation tissue. The DRC-1+ mononuclear cells were curiously encountered in the peripheral blood of some autoimmune disease patients in contrast with no identification in healthy persons. Furthermore some DRC-1+ cells obtained from autoimmune patient were confirmed to proliferate in culture.