Identification of plasmacytoid T cells in lymphoid hyperplasia of the skin.
Well-defined clusters of plasmacytoid T cells were identified in two cases of lymphoid hyperplasia of the skin. With the use of paraffin-embedded and frozen sections and 46 different antibodies, the antigenic profile of plasmacytoid T cells was obtained. Corresponding to plasmacytoid T cells in reactive and neoplastic lymph node conditions, plasmacytoid T cells of the skin were devoid of most T-cell-restricted differentiation antigens CD2, CD3, CD5, and CD8 while expressing monocyte/macrophage-related antigens recognized by Ki-M6 and Ki-M7. In addition, plasmacytoid T cells were positive for CD4, CD45, HLA class II antigens (HLA-DR, Leu-10, MB3, LN2, LN3) and the transferrin receptor. Furthermore, they reacted with anti-Leu-8, MB1, Ki-B3 (CD45R), and MT1. Thus plasma-cytoid T cells are considered to be mononuclear cells with monocyte/macrophage differentiation rather than T lymphocytes. In addition, our findings substantiate the concept that plasmacytoid T cells may function as a hitherto unrecognized subgroup of antigen-presenting cells in the skin.
Eckert
F
F
Department of Dermatology, University of Munich, West Germany.
Schmid
U
U
D000911:Antibodies, Monoclonal; D015703:Antigens, CD / Q000032:analysis; D001402:B-Lymphocytes / Q000166:cytology; D015704:CD4 Antigens / Q000032:analysis; D006801:Humans; D006965:Hyperplasia / Q000276:immunology / Q000473:pathology; D008221:Lymphoid Tissue / Q000473:pathology; D010950:Plasma Cells / Q000166:cytology* / Q000276:immunology; D012867:Skin / Q000473:pathology*; D013601:T-Lymphocytes / Q000166:cytology* / Q000276:immunology
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D015704:CD4 Antigens