Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019621 (Langerhans cell histiocytosis)
 3,250 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Expression of adhesion molecules was investigated in six biopsy specimens of Langerhans' cell histiocytosis using immunocytochemistry. Cells with Langerhans' cell histiocytosis morphology were stained for ICAM-1, for the beta-1 integrins alpha-4 (VLA-4) and alpha-5 (VLA-5) , and for the beta-2 integrins LFA-1, MAC-1 and p150,95. This pattern of reactivity was different from that of epidermal Langerhans' cells of the normal skin which were not immunostained. A variable number of CD68+ multinucleated giant cells was present in five biopsies. They were less reactive than the cells of Langerhans' cell histiocytosis for alpha-4 (VLA-4) and LFA-1, were positive for MAC-1 and p150,95 and were characterized by prominent expression of the beta-1 integrins alpha-2 (VLA-2), alpha-3 (VLA-3) and of VnR (alpha-v/beta-3). The repertoire of adhesion molecules expressed by giant cells is indicative of profound cell-matrix interactions, whereas that of Langerhans' histiocytosis cells suggests particularly active cell-cell interactions. Blood vessels of the lesions were stained for beta-1 integrins, for vitronectin receptor and for molecules involved in adhesion and trans-endothelial migration of circulating leukocytes, such as ICAM-1, VCAM-1 and E-selectin. Additional findings were the observation of CD1a + multinucleated giant cells in a single case, suggesting a possible lineage relationship with the histiocytosis cells, and the demonstration of some Ki-67+ Langerhans' cell histiocytosis cells and CD1a+ mitotic figures in four of six cases, indicating local proliferation of Langerhans' histiocytosis cells.
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PMID:Expression of adhesion molecules in Langerhans' cell histiocytosis. 769 6

Langerhans' cell histiocytosis (LCH) is characterized by the presence of large mononucleated cells, associated with inflammatory cells. The Langerhans' cell (LC) lineage of the mononucleated cells is suggested by the presence of Birbeck granules and the expression of CD1a. We investigated the presence of 14 markers expressed by normal LCs in vitro. Nine skin and one lymph node frozen biopsies of LCH children were analysed by in situ immunohistochemistry. The data were compared with six skin and five lymph node frozen biopsies. LCH cells of the ten samples were positive for all 14 LC markers. We observed three different groups of markers, according to the respective staining of normal LCs and LCH cells. Group 1 included DR, DQ, CD1a, CD1c, and ICAM-3. Markers of group 1 were present on the majority of both normal LCs and LCH cells. Group 2 included CD1b, CD4, LFA-1, LFA-3, CD32, and CD68. Markers of group 2 were detected on the majority of LCH cells, but only on a fraction of normal LCs. Group 3 included CD11b, CD24, and B7/BB1. Markers of this group were detected on LCH cells, but not on normal LCs. This in situ immunohistochemical study confirms that LCH cells belong to the LC lineage. The different clinical LCH syndromes had the same immunohistochemical staining. The expression of some markers of groups 2 and 3 is known to be related to the activation of LCs in vitro. Our study suggests that LCH cells are activated LCs.
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PMID:Langerhans' cell histiocytosis cells are activated Langerhans' cells. 796 9

ICAM-3 is a newly recognized adhesion molecule, which is a member of the immunoglobulin supergene family of ICAMs, and has been shown to be identical with the CD50 antigen. Recent functional studies have shown that ICAM-3 is a ligand for LFA-1, and plays an important part in immune reactions. To date, very few data exist in the literature concerning its expression in the skin. In the present study, we investigated the expression of ICAM-3 in normal skin and in 98 biopsy specimens of various inflammatory and neoplastic dermatoses. ICAM-3 was found to be expressed by epidermal CD1a+ Langerhans cells, by cells of Langerhans cell histiocytosis, by T and B lymphocytes infiltrating the dermis in cutaneous lymphomas and in a wide spectrum of inflammatory dermatoses. Epidermal keratinocytes were consistently negative; endothelial expression of ICAM-3 was observed in six of the 98 cases. These results show that ICAM-3 is constitutively and widely expressed by cells participating in inflammatory dermatoses (including Langerhans cells and T and B lymphocytes), and that it can be, albeit rarely, induced on endothelial cells and dermal dendrocytes. These results highlight the important part that ICAM-3 may play in cutaneous inflammatory and immune reactions.
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PMID:Expression of ICAM-3/CD50 in normal and diseased skin. 854 91

Hemophagocytic lymphohistiocytosis (HLH) and Langerhans cell histiocytosis (LCH) are members of a group of rare heterogenous disorders, the histiocytoses, characterized by uncontrolled accumulation of pleomorphic infiltrates of leukocytes. The etiology of these diseases is mainly unknown. CD45 is a hemopoietic cell specific tyrosine phosphatase essential for antigen receptor mediated signaling in lymphocytes and different patterns of CD45 splicing are associated with distinct functions. Recently a polymorphism (C77G) in exon 4 of CD45 causing abnormal CD45 splicing and a point mutation affecting CD45 dimerization were implicated in multiple sclerosis in humans and lymphoproliferation and autoimmunity in mice respectively. Here we show that two patients with HLH exhibited abnormal CD45 splicing caused by the C77G variant allele, while a further 21 HLH patients have normal CD45. We have also examined 62 LCH patients and found three to have the C77G mutation. Peripheral blood thymus-derived (T) CD8(+) cells from normal individuals carrying the C77G mutation show a significant decrease in the proportion of cells expressing L-selectin and increased frequency of cells with LFA-1(hi) expression. It remains to be established whether C77G is a contributing factor in these histiocytic disorders.
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PMID:Abnormal cell surface antigen expression in individuals with variant CD45 splicing and histiocytosis. 1463 Sep 80