Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06126 (CD1a)
 2,221 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 62-year-old female with histiocytosis X presented with a vulvar ulcer. Multiple osteolytic lesions were later detected. Histological examination of the ulcerated skin showed diffuse proliferation of histiocytic cells with folded nuclei and pale eosinophilic cytoplasm. Immunohistochemistry revealed S100 protein and vimentin as well as CD1a, CD4, and HLA-DR antigens in the proliferating cells. Electron microscopy demonstrated Birbeck granules in the cytoplasm of the cells. The patient was successfully treated by complete surgical excision of the ulcer followed by radiotherapy for recurrent vulvar erythema.
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PMID:An adult case of histiocytosis X with a vulvar ulcer and multiple bone lesions. 805 99

Langerhans cell histiocytosis is difficult to study because of its rarity. Although recent studies indicate that it may be a clonal proliferation this does not prove that it is a malignant tumour. New methods for culturing dendritic cells and their precursors provide the opportunity to resolve issues relating to clonality, underlying genetic lesions and functional abnormalities in LCH or other lesional cells. The expression of the CD1a antigen on LCH cells provides a target for therapy.
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PMID:The scientific challenge of Langerhans cell histiocytosis. 807 11

Langerhans cell histiocytosis (LCH), formerly histiocytosis X, is a rare disorder of unknown aetiology and pathogenesis which is characterized by clinical heterogeneity and an unpredictable course. LCH is considered to be a reactive, proliferative disease. The pathognomonic cell in the lesion has been shown to be identical or very similar to the Langerhans cell. Immunophenotyping studies have shown the cell to be CD1a (OKT-6), S-100 protein, HLA-DR, and CD4 positive; ultrastructurally, the presence of intracytoplasmic Birbeck granules is the hallmark of the entity. The lesions may be localized or generalized. Due to the lack of an accepted classification system for the stage of the disease and its rarity, very few comparative therapy studies have been carried out. Recently, the Histiocyte Society has suggested diagnostic criteria for LCH, and established a program of initial evaluation of the patient in order to start controlled treatment trials. Traditionally, chemotherapy has been preferred with a trend over time towards a more conservative approach. The rate of sequelae is high and connected to a chronic course of recurrent multiosseous disease. Case fatality is strongly associated to development of organ dysfunction seen in disseminated disease, which is especially seen at low age (< 2 years) of onset.
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PMID:[Langerhans-cell histiocytosis (histiocytosis X) in children]. 831 26

The cutaneous lymphocyte associated antigen (CLA) recognized by the monoclonal antibody (moAb) HECA-452 plays a major role in the homing of lymphocyte subpopulations to the skin by binding to E-selectin on dermal microvessels. The factors responsible for the immigration of Langerhans cells (LC) and their precursors into the skin are still unknown, but because normal resting LC are also capable of expressing CLA, the antigen was proposed as a candidate LC-homing structure. To gain insight into these mechanisms, the expression of HECA-452 on neoplastic LC within and outside the skin was investigated in paraffin-embedded sections from 44 patients with localized and disseminated forms of Langerhans cell histiocytosis (LCH) presenting with proliferating cells positive for CD45, CD1a, S100 and HLA-DR. Irrespective of the clinical presentation or the type of organ involved, HECA-452 positive LC were detected in all biopsies tested (range 5->90%). The most prominent HECA-452 reactivity was observed in skin lesions and in areas with accumulations of eosinophilic granulocytes. Our data provide evidence for heterogeneous expression of sLex/sLea structures in various stages of activated and/or differentiated LCH cells. Remarkably, CLA-antigen expression on LCH-cells was not restricted to cutaneous sites. In view of recent findings on the expression of HECA-452 on resting epidermal LC, our data are compatible with the view that local cytokine production by keratinocytes or cells from the surrounding infiltrate induce and/or modulate CLA expression on LC in both cutaneous and extra-cutaneous sites.
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PMID:Expression of the monoclonal antibody HECA-452 defined E-selectin ligands in Langerhans cell histiocytosis. 862 76

The cutaneous histiocytoses are best divided in the Langerhans' cell histiocytoses and non-Langerhans' cell histiocytoses. In the former group, the cells react with S100 and CD1a antibodies, while in the latter group they express a variety of macrophage markers. Xanthogranuloma is a frequent childhood tumor and the only common non-Langerhans' cell histiocytosis. Xanthogranulomas contain a mixture of several different types of histiocytes that also appear in more pure forms as both solitary tumors and disseminated processes. The varying histiocyte morphology provides a unifying concept for non-Langerhans' cell histiocytoses.
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PMID:The non-Langerhans' cell histiocytoses in childhood. 888 34

The immunophenotype of 6 cases of Langerhans cell histiocytosis (LCH) of the hypothalamus and 3 cases of cranial bone manifestation of LCH was investigated by means of immunohistochemistry on paraffin sections. Antibodies against S 100 protein, lysozyme, CD68 (PG-M1), CD68 (KP1), HLA-DR, beta 2 microglobulin, placental alkaline phosphatase (PLAP), the monoclonal antibody MAC 387, and a monoclonal antibody against CD1a were used. All examined cases showed positive staining of lesional cells for S 100 protein, HLA-DR, beta 2 microglobulin, macrophage associated markers and CD1a. According to the "confidence levels" of the Writing Group of the Histiocyte Society [Chu et al. 1987], a "definite diagnosis" of LCH requires the demonstration either of Birbeck granules in lesional cells by electron microscopy, or of CD1a antigenic determinants on the surface of lesional cells. Since electron microscopy of these rare CNS lesions is not possible in many cases, we are now able to give a definite diagnosis of LCH of the hypothalamus by means of immunohistochemistry for CD1 a on routinely fixed and processed tissue.
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PMID:Langerhans cell histiocytosis of the hypothalamus: diagnostic value of immunohistochemistry. 892 2

An unusual case of primary parenchymal Langerhans' cell histiocytosis of the central nervous system is reported. The definitive diagnosis was obtained by ultrastructural detection of Birbeck granules and by immunohistochemical evidence of CD1a expression. Despite complete surgical resection, there was an early recurrence with multiple central nervous system metastases leading to a fatal outcome.
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PMID:Primary Langerhans' cell histiocytosis of the central nervous system with fatal outcome. Case report. 952 34

Involvement of the thyroid gland by Langerhans' cell histiocytosis is quite rare. We describe the case of a 58-year-old man referred for treatment of a progressively enlarging goitre. The trachea was severely stenotic and adjacent structures such as the left carotid vein and the thyroid cartilage were also involved. Central diabetes insipidus and severe combined immunodeficiency were associated. Although fine needle aspiration biopsy of the thyroid was initially interpreted as papillary carcinoma, anaplastic thyroid cancer was suspected. Treatment with prednisolone, doxorubicin and irradiation controlled the tracheal compression. A diagnosis of thyroid Langerhans' cell histiocytosis was finally made on the basis of the presence of Birbeck granules and CD1a and CD4 antigen in the thyroid tumour cells. Furthermore, positive staining for CD68 and lysozyme suggested that the tumour cells may have had the character of phagocytic cells in addition to their dendritic cell nature. This is the first case of thyroid involvement by malignant histiocytosis of Langerhans' cell type with unusual phagocytic markers.
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PMID:Thyroid involvement by malignant histiocytosis of Langerhans' cell type. 894 75

We evaluated CD1a-positive cells in bronchoalveolar lavage samples from children with Langerhans cell histiocytosis (LCH). All children with multifocal LCH and pulmonary symptoms scored higher than 5% (30.6% +/- 7.2%), whereas those with other lung disorders scored much less than 5%. In children with multifocal LCH, bronchoalveolar lavage fluid abnormalities can precede pulmonary symptoms. During chemotherapy the CD1a-positive cell count lends to decrease.
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PMID:Cd1a-positive cells in bronchoalveolar lavage samples from children with Langerhans cell histiocytosis. 896 36

Dendritic cells are antigen-presenting cells derived from the hematopoietic stem cell. The dendritic cell family includes Langerhans' cells (CD1a-positive dendritic cells of the skin), and antigen-presenting cells that are found in the lymphoreticular system and throughout the organ parenchyme. Dendritic cells play a key role in both the primary and secondary immune responses. Several studies indicate that these cells participate in antitumor immunity, tumor surveillance, graft-versus-host disease, and in the pathogenesis of clinical syndromes of unknown origin or those induced by viruses, such as the human immunodeficiency virus. Different disorders are characterized by an abnormal proliferation and accumulation of dendritic cells; for example, the Langerhans' histiocytes, which accumulate in Langerhans' cell histiocytosis. In this review the immunophenotypic, morphological, and functional characteristics of the dendritic cell family is described. The clinical and laboratory studies suggesting a unique role for these cells in various syndromes and diseases are reviewed. The Langerhans' cell histiocytoses and the malignant disorders associated with transformation of cells belonging to the dendritic cell family, are discussed.
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PMID:Physiology and pathophysiology of dendritic cells. 949 Feb 85


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