title: The phenotypic spectrum of histiocytosis X cells.
abstract: Proliferating cells in histiocytosis X (histiocytosis X cells) share many structural and immunophenotypic features with Langerhans cells, leading to the assumption that histiocytosis X represents a proliferative disorder of Langerhans cells. Because, depending on their state of activation and/or differentiation, Langerhans cells exhibit a varying immunophenotype, we investigated whether histiocytosis X cells display a similar phenotypic heterogeneity and, if so, whether the heterogenous biological behavior of histiocytosis X is reflected by differences in the immunophenotype of the proliferating cells. In 21 patients suffering from different clinical manifestations of histiocytosis X, proliferating cells uniformly expressed class I and II alloantigens, T200, CD1, CD4, and S100 protein. In 12 of 21 cases, histiocytosis X cells additionally exhibited immunocytochemically detectable amounts of C3b and C3bi receptors and certain monocyte/macrophage antigens (CDw14, Ki-M1, Ki-M6). This immunophenotypic heterogeneity of histiocytosis X cells could not be correlated with clinical course, prognosis, and final outcome of the disease in a given patient. The capacity of histiocytosis X cells to immunophenotypically mimic various states of Langerhans cell activation and/or differentiation, however, underscores the concept of histiocytosis X as a proliferative disorder of Langerhans cell origin.
authors.affiliation: Department of Dermatology I, University of Vienna Medical School, Austria.
authors.forename: V
authors.initials: V
authors.lastname: Groh
authors.forename: H
authors.initials: H
authors.lastname: Gadner
authors.forename: T
authors.initials: T
authors.lastname: Radaszkiewicz
authors.forename: K
authors.initials: K
authors.lastname: Rappersberger
authors.forename: K
authors.initials: K
authors.lastname: Konrad
authors.forename: K
authors.initials: K
authors.lastname: Wolff
authors.forename: G
authors.initials: G
authors.lastname: Stingl
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D006646:Histiocytosis, Langerhans-Cell / Q000235:genetics* / Q000473:pathology; D006801:Humans; D007124:Immunoenzyme Techniques; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008854:Microscopy, Electron; D010641:Phenotype