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Query: UMLS:C0019621 (Langerhans cell histiocytosis)
 3,250 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The immunophenotype and proliferation fraction have been investigated in 26 cases of Langerhans' cell histiocytosis (LCH). In all cases LCH cells were positive for S-100 protein, CD1a, or both. In most cases LCH cells expressed the macrophage-associated marker CD68 and in two cases they contained lysozyme. Expression of both cytoplasmic CD2 and CD3 was observed in cryostat sections. An unexpected finding was the presence of placental alkaline phosphatase in LCH cells. Langerhans' cells in normal skin were negative for both CD2 and CD3, but a proportion contained placental alkaline phosphatase. In four cases of Rosai-Dorfman disease the histiocytic cells, which share certain immunophenotypic properties with Langerhans' cells, also were positive for placental alkaline phosphatase. A significant proportion of LCH cells stained positively with the antibody to proliferating cell nuclear antigen and also with the proliferation marker Ki-S1. A good correlation between the percentage of Ki-67-positive and proliferating cell nuclear antigen- and Ki-S1-positive cells, respectively, was observed. Thus, in comparison with their putative precursors, LCH cells have an aberrant phenotype and are proliferating locally. This might suggest that LCH is a neoplastic rather than a reactive process.
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PMID:Langerhans' cell histiocytosis (histiocytosis X): immunophenotype and growth fraction. 769 Jul 35

To date, the rare primary histiocytoses of the skin are diagnosed definitively on the basis of the clinical symptoms, H&E-stained sections, and demonstration of CD1 positivity in frozen sections and of Birbeck granules on electron microscopy. The improvement and analysis of antibodies with the ability to react in paraffin tissue allow retrospective evaluation and classification of these disorders. The antibodies for S-100-protein, peanut agglutinin (PNA) and PCNA (proliferating cell nuclear antigen) have been advocated for differentiation of the specific cells of Langerhans cell histiocytosis (LCH) from other histiocytic cell systems. To date the non-Langerhans cell histiocytoses (non-LCH) have no common ultrastructural and immunohistochemical characteristics. The infiltrate is made up of multiple cell populations, which are of significance for the cellular pathobiology (subtypes of monocytes/macrophages and dendritic cells). The number and distribution of the different monocyte/macrophages and dendritic cells and their ability to react with immunohistochemical markers in paraffin tissue can be completely different in different clinical entities. The antibodies against factor XIIIa (shown on xanthoma disseminatum) and the monoclonal antibody Ki-M1P (shown on juvenile xanthogranuloma) seem to be valuable in discrimination between LCH and non-LCH. Both markers show a positive staining pattern with the characteristic large macrophages. In juvenile xanthogranuloma, the foam cells and giant cells express Ki-M1P, KP1 and anti-cathepsin B. Other monocyte/macrophage markers with the ability to react in paraffin tissue, such as Mac387, lysozyme, alpha 1-antitrypsin and Leu-M1 (Anti-CD 15), in contrast, did not show a typical staining pattern with the characteristic large macrophages dominating the histological picture.
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PMID:[Possibilities and limits of paraffin-embedded cell markers in diagnosis of primary cutaneous histiocytosis]. 775 39

Histological features of tuberculosis are caseation necrosis and epithelioid cell granuloma formation. Both phenomena are interpreted as expression of cellular immunity. Caseation necrosis is thought to be immunopathology and epithelioid cell granuloma formation is considered to be expression of protective immunity. Recently roles of cytokines for granuloma formation are gradually elucidated. In this symposium, mechanisms and functions of necrosis and granuloma formation Dr. Akagawa reported differentiation of two types of phenotypically different macrophages from human monocytes by GM (granulocyte-macrophage)-CSF or M (macrophage)-CSF. Interestingly such a basic differentiation induced by CSF was affected by IL-4 (interleukin-4). Langerhans-like dendritic cells were generated by cooperation of GM-CSF and IL-4, and multinucleated cells were generated by cooperation of IL-4 and M-CSF. Dr. Fukuda reported human Langerhans cell granulomatosis (LCG) from the pathological and immunohistochemical standpoints. In situ proliferation of LCs in the LCG was demonstrated by immunohistochemistry using antibody to PCNA (proliferating cell nuclear antigen) which is used to detect proliferating cells. In the course of granuloma formation, damage and disruption of lung structure such as alveolar basement membrane and elastic tissue framework, and reactive intraluminar fibrosis was observed. Mechanism of cystic dilation was also reported. Cytokines might play important roles in these events. Dr. Ina demonstrated experimental epithelioid cell granuloma formation. Extract (granuloma inducing factor, GIF) from Schistosoma mansoni Egg-induced granuloma, TNF -alpha, or IL-1 beta were coated, individually on the surface of beads, then these beads were inoculated to rat's skins or cultured with rat's monocytes. Four weeks later, epithelioid cell granuloma was demonstrated histologically and electronmicroscopically around beads in vitro and in vivo. GIF-induced granuloma was more organized than cytokine-induced ones. In vitro using human monocytes, activated macrophages accumulated around beads of which cytokines or GIF were coated. It was suspected that many cytokines or other factors are needed to make epithelioid cell granuloma. Dr. Sakamoto showed the presence of acid fast bacilli and various inflammatory cells including lymphocytes and macrophages in the tuberculous caseous necrosis after exudative reaction (E-necrosis) by immunohistochemistry. But no acid fast bacilli or inflammatory cells were found in the caseous necrosis after productive reaction (P-necrosis). TNF-alpha (tumor necrosis factor-alpha) and IL-4 were stained in the E-necrosis and IL-4 and ICAM-1 (intercellular adhesion molecule-1) were positively stained in the cytoplasm of epithelioid cells by immunohistochemistry. It was suspected that many cells and cytokines were involved in epithelioid cell granuloma formation and caseous necrosis formation.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[The 69th annual meeting symposium. II: Mechanism of necrotizing granuloma formation and its function]. 779 74

Pulmonary Langerhans cell granulomatosis (LCG), also called histiocytosis X, is a disorder of unknown etiology characterized by the presence of destructive granulomas containing numerous Langerhans cells (LCs). The process may be localized or multifocal, and it remains unclear whether the same pathogenic mechanism is involved in all forms of the disease. It is often assumed that the massive accumulation of LCs at the sites of the lesions results from the abnormal proliferation of these cells, although it has been suggested that LCG in adults, at least in the lung, could be a reactive disorder initiated by activated LCs. Little is known, however, concerning the mechanisms responsible for the accumulation of large numbers of LCs in the course of the disease, and the relative contribution of recruitment and local proliferation of these cells remains to be established. To investigate this question, the proportion of replicating LCs was evaluated in biopsied granulomas from patients with localized or diffuse form of LCG by means of several histopathological techniques currently used in assessment of cell proliferation. The findings demonstrate that, except for proliferating cell nuclear antigen (PCNA), all parameters measured are low in all forms of the disease. They are similar to those of renewing epithelial cells and clearly less than those of neoplastic cells. These data strongly suggest that LCs in LCG granulomas are not a rapidly dividing cell population and that local LC replication makes only a minimal contribution to granuloma maintenance. Caution appears to be necessary in the use of PCNA as a marker of growth fraction.
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PMID:Langerhans cells in Langerhans cell granulomatosis are not actively proliferating cells. 958 81

We present the case of a woman with diabetes insipidus with subsequent genital and multiorgan Langerhans cell histiocytosis (LCH). A monolateral and slightly infiltrated erythematous plaque of the vulva was observed. Hematoxylin and eosin and immunophenotypic studies were performed. The primary antibodies used were monoclonal antibody to S100, CD1a, CD34, HLA-DR, PCNA, CD45Ro, CD40, and langerin. The histology of the infiltrates revealed a granulomatous reaction pattern, with extensive aggregates of histiocyte proliferation. The histiocytes, morphologically characterized by a pale staining of cytoplasm surrounding a grooved reniform nucleus, sometimes contained small distinct nucleoli. Lymphocytes, eosinophils, macrophages, and both plasma cells and giant cells typically infiltrated the lesions. Cells CD1a+ and S100+ infiltrated the epidermic and were dispersed over the infiltrates as well as in clusters, and around the vessels. A considerable number of CD40-expressing cells were restricted to CD1a+ LCH cells. The specimen contained a high percentage of langerin+ cells in both the dermis and the epidermis. The clinical manifestations of LCH affecting the genital area can be diverse, and in most patients take the form of ulcers or erythematous plaques. Histopathologic examination of the lesion evidences a mixture of Langerhans cell histiocytes (CD1a+, S100+, HLADr+, CD207+, CD 40+), lymphocytes (predominantly helper [CD4] CD 45 Ro+), eosinophils, and macrophages. Each of the cell types produces a "cytokine storm." Many of the cytokines favor recruitment of Langerhans cell progenitors and rescue the Langerhans cell histiocytes from apoptosis.
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PMID:Clinical and immunohistochemical evaluation of the vulvar Langerhans cell histiocytosis. 1907 26