title: The human progenitor cell antigen (CD34) is localized on endothelial cells, dermal dendritic cells, and perifollicular cells in formalin-fixed normal skin, and on proliferating endothelial cells and stromal spindle-shaped cells in Kaposi's sarcoma.
abstract: The human progenitor cell antigen (CD34) is selectively expressed on hematopoietic progenitor cells in the bone marrow. In either cryostat sections of snap-frozen skin, or formalin-fixed paraffin-embedded sections of normal skin, anti-CD34 monoclonal antibody immunostained vascular endothelial cells and perivascular/interstitial dendritic cells, particularly in the reticular dermis. A distinctive population of perifollicular spindle-shaped cells in the midportion of the follicle (ie, bulge area), which is the site of the putative hair follicle stem cells, were CD34 positive, as were spindle-shaped cells in and around the eccrine glands accentuating their basement membrane zone. In patch/plaque--and tumor-stage acquired immunodeficiency syndrome-associated Kaposi's sarcoma lesions, CD34 expression was present on both the proliferating endothelial cells as well as the spindle-shaped stromal cells. CD34 positive endothelial cells and spindle-shaped stromal cells may play important participatory and supportive functions in both normal and diseased skin.
authors.affiliation: Department of Pathology, University of Michigan Medical Center, Ann Arbor 48109-0602.
authors.forename: B J
authors.initials: BJ
authors.lastname: Nickoloff
mesh_terms: D015703:Antigens, CD / Q000302:isolation & purification*; D003713:Dendritic Cells / Q000737:chemistry*; D004727:Endothelium / Q000737:chemistry* / Q000166:cytology; D006801:Humans; D012514:Sarcoma, Kaposi / Q000737:chemistry* / Q000473:pathology; D012867:Skin / Q000737:chemistry* / Q000166:cytology
chemical_list: D015703:Antigens, CD