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)

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

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

Interdigitating dendritic cell tumor is an extremely rare neoplasm that mainly occurs in lymph nodes. An example of such a tumor in the testis, a hitherto unreported site, is described. Grossly, the tumor was light tan with a uniform solid appearance, replacing virtually the entire testis. Microscopically, it was formed by whorls and fascicles of spindle cells intermingling with small lymphocytes. Such a histologic appearance can, however, mimic a wide variety of other tumors and tumor-like lesions, among which mesenchymal sarcoma, spindle cell carcinoma, follicular dendritic cell tumor, and inflammatory pseudotumor are the main differential diagnoses. Immunohistochemical studies showed that the spindle tumor cells were strongly and diffusely positive for S-100 protein and vimentin. They were also focally positive for CD68 and CD4, but were uniformly negative for leukocyte common antigen, CD1a, CD3, CD20, CD21, CD23, CD34, CD35, actin, desmin, HMB45, cytokeratins, and placental alkaline phosphatase. Ultrastructurally, the tumor cells possessed complex interdigitating cytoplasmic dendritic processes, with abundant rough endoplasmic reticulum and mitochondria in their cytoplasm. An in situ hybridization study for Epstein-Barr virus was negative. The pathologist should be aware of such an entity and consider it in the list of differential diagnoses for unusual spindle cell lesions with a significant background population of small lymphocytes. However, because of its nonspecific histologic appearance, additional immunohistochemical and electron microscopic studies are generally required for its definitive diagnosis.
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PMID:Interdigitating dendritic cell tumor of the testis: a novel testicular spindle cell neoplasm. 1047 77