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)

Lymph nodes contain nonlymphoid accessory cells including follicular dendritic cells (FDCs), interdigitating dendritic cells (IDCs) and fibroblastic reticular cells (FBRCs). Neoplasms derived from FDCs are uncommon, and those of IDC origin are even more rare. We report the clinicopathologic features of 11 reticulum cell neoplasms, including 2 of FBRC origin. There were seven male patients and four female patients ranging in age from 13 to 73 years. All cases involved lymph nodes (cervical or supraclavicular-6 cases), (abdominal--2 cases), epitrochlear (1 case); two had more than one site of involvement (cervical lymph node and mediastinum--1 case, cervical and abdominal lymph nodes--1 case). One case of FDC tumor had concomitant Castleman's disease, plasma cell variant. Each neoplasm showed similar histology with oval-to-spindle-shaped cells in a storiform or fascicular pattern. Based on immunophenotypic findings, the neoplasms were classified as FDC (five cases), IDC (two cases), FBRC (three cases), and reticulum cell neoplasm, not otherwise specified (one case). The FDC tumors showed immunoreactivity for CD21 or CD35, vimentin, and CD68. The IDC tumors showed strong positivity for S-100 protein and variable positivity for CD68 and CD1a. The cases derived from FBRCs were positive for vimentin, desmin, and smooth-muscle actin. The neoplasm classified as reticulum cell neoplasm, not otherwise specified had similar morphologic features but showed only equivocal positivity for CD68 and vimentin. Follow-up was available for 9 of 11 (82%) cases with a mean of 3.5 years. Four of five patients with FDC tumors were alive with disease when last seen; the fifth is alive and well with no evidence of disease at 4-year follow-up. One patient with IDC tumor had a recurrence in a different nodal site. Two patients with FBRC tumor were disease free at follow-up of 2 years and 8 years, respectively. The patient with reticulum cell neoplasm, not otherwise specified, was alive and disease free 8 years after diagnosis.
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PMID:Reticulum cell neoplasms of lymph nodes: a clinicopathologic study of 11 cases with recognition of a new subtype derived from fibroblastic reticular cells. 973 36

The escape of malignant cells from the immune response against the tumor may result from a defective differentiation or function of professional antigen-presenting cells (APC), ie, dendritic cells (DC). To test this hypothesis, the effect of human renal cell carcinoma cell lines (RCC) on the development of DC from CD34(+) progenitors was investigated in vitro. RCC cell lines were found to release soluble factors that inhibit the differentiation of CD34(+) cells into DC and trigger their commitment towards monocytic cells (CD14(+)CD64(+)CD1a-CD86(-)CD80(-)HLA-D Rlow) with a potent phagocytic capacity but lacking APC function. RCC CM were found to act on the two distinct subpopulations emerging in the culture at day 6 ([CD14(+)CD1a-] and [CD14(-)CD1a+]) by inhibiting the differentiation into DC of [CD14(+)CD1a-] precursors and blocking the acquisition of APC function of the [CD14(-)CD1a+] derived DC. Interleukin-6 (IL-6) and macrophage colony-stimulating factor (M-CSF) were found to be responsible for this phenomenon: antibodies against IL-6 and M-CSF abrogated the inhibitory effects of RCC CM; and recombinant IL-6 and/or M-CSF inhibited the differentiation of DC similarly to RCC CM. The inhibition of DC differentiation by RCC CM was preceeded by an induction of M-CSF receptor (M-CSFR; CD115) and a loss of granulocyte-macrophage colony-stimulating factor receptor (GM-CSFR; CD116) expression at the surface of CD34(+) cells, two phenomenon reversed by anti-IL-6/IL-6R and anti-M-CSF antibodies, respectively. Finally, a panel of tumor cell lines producing IL-6 and M-CSF induced similar effects. Taken together, the results suggest that the inhibition of DC development could represent a frequent mechanism by which tumor cells will escape immune recognition.
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PMID:Inhibition of the differentiation of dendritic cells from CD34(+) progenitors by tumor cells: role of interleukin-6 and macrophage colony-stimulating factor. 984 45

An acute leukemia with an unusual immunophenotype developed in a 17-year-old girl. At the initial presentation, extramedullary involvement was not evident, but with advancing disease, massive splenomegaly and an osteolytic rib tumor developed. The disease was aggressive and refractory to intensive chemotherapeutic regimens for myeloid and lymphoid malignancies, and the patient died 3 months after the initial presentation. The leukemic cells were of irregular shape and variable size; they had deeply indented or bi-lobed nuclei and relatively fine, azurophilic granules in their cytoplasm. They were positive for acid phosphatase and beta-glucuronidase in granular staining, but they were negative for myeloperoxidase. The leukemic cells had a unique immunophenotype: it was positive for T-cell antigens (CD1a, CD2, cytoplasmic CD3, CD4), myeloid antigens (CD13 and CD33), NK-cell antigen (CD56), CD19 and CD30. DNA analysis revealed no gene rearrangement in the T-cell receptor beta, gamma and delta, or immunoglobulin heavy chain genes. The leukemic cells of our patient are thought to have arisen from the transformation of a putative precursor cell common to both the T- and NK-cell lineage in the bone marrow. The current literature on precursor NK-cell malignancy is reviewed, and its clinicopathological feature is discussed.
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PMID:Acute leukemia with the phenotype of a natural killer/T cell bipotential precursor. 1003 70

We describe a case of granulomatous mycosis fungoides, tumor stage, mimicking sarcoidosis in an 82-year-old man with a 2-year history of skin disease. The final diagnosis was established after one of seven biopsy specimens showed a nongranulomatous histologic picture of patch-stage mycosis fungoides. Monoclonality was proven for the lymphocytic population by T-cell-receptor rearrangement studies. The unusually extensive granulomatous inflammation with huge giant cells surrounded by CD1a-positive cells in the other six biopsy specimens was suggestive of the histopathology of granulomatous slack skin, another rare granulomatous cutaneous T-cell lymphoma. Because both a clinical and histologic overlap between granulomatous mycosis fungoides and granulomatous slack skin have been reported in the literature, we conclude that they may belong to the spectrum of a single disease.
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PMID:Granulomatous mycosis fungoides: report of a case with some histopathologic features of granulomatous slack skin. 1021 76

Cutaneous lymphadenoma is an uncommon basaloid epithelial tumor of uncertain histogenesis, most recently classified as a variant of trichoblastoma. Because characteristic immunohistochemical findings have been reported in trichoblastomas, we evaluated the staining patterns of five cutaneous lymphadenomas and compared the results to those of ten trichoblastomas and ten nodular basal cell carcinomas (BCCs), using antibodies to cytokeratin 20 (CK20), bcl-2, and CD34. In addition, because lymphadenomas contain intraepithelial S100-positive putative Langerhans cells, we compared staining of all tumor groups for S100 protein and CD1a. We also attempted to corroborate recent reports of CD30-positive activated lymphocytes in lymphadenomas. We identified CK20-positive Merkel cells in 3/5 lymphadenomas, 7/10 trichoblastomas, and none of the BCCs. Staining for bcl-2 accentuated the peripheral epithelial layer in all lymphadenomas and in 3/10 trichoblastomas, while the remaining trichoblastomas and all BCCs stained diffusely. There was stromal staining with CD34 in two lymphadenoma, 4 trichoblastomas, and 3 BCCs. All lymphadenomas featured numerous intraepithelial S100-positive cells which were also positive for CD1a in three cases tested. In addition, 8/10 trichoblastomas and 2/10 BCCs contained modest numbers of cells labelling for S100 and CD1a. Two of three lymphadenomas contained rare single cells resembling histiocytes faintly positive for CD30, and similar cells labelled for CD68. We conclude that the similar staining patterns of lymphadenomas and trichoblastomas support the classification of lymphadenoma as a variant of trichoblastoma. Staining with CD34 does not reliably distinguish between these tumors and BCCs. Lymphadenomas, trichoblastomas, and BCCs may all contain Langerhans' cells. The relationship between these cells and the striking lymphoid infiltrates seen in lymphadenomas is not clear. In our cases, the CD30-positive cells in lymphadenomas appear to represent histiocytes rather than activated lymphocytes.
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PMID:Immunohistochemical comparison of cutaneous lymphadenoma, trichoblastoma, and basal cell carcinoma: support for classification of lymphadenoma as a variant of trichoblastoma. 1023 76

We describe 18 cases of a distinctive morphologic variant of primary thymic epithelial neoplasm characterized by a micronodular growth pattern associated with florid lymphoid follicular hyperplasia of the stroma. The tumors occurred in seven women and 11 men aged 41 to 76 years (mean, 58 years). All cases were asymptomatic and discovered incidentally on routine chest radiograph or during coronary artery bypass surgery. The tumors measured from 3 to 10 cm in greatest dimension and were well circumscribed and encapsulated. In seven cases, the lesions were grossly described as cystic or partially cystic masses. Histologically, they were characterized by a proliferation of small tumor nodules separated by abundant lymphoid stroma with prominent germinal centers. The nodules were composed of spindle cells containing oval nuclei devoid of atypia or mitotic activity. Immunohistochemical studies showed strong positivity of the spindle tumor cells for CAM 5.2 and broad spectrum keratin antibodies. The surrounding lymphoid cell population was strongly positive for LCA and L26 and showed a polyclonal pattern of staining for kappa and lambda. Stains for UCHL-1, CD1a, CD3, CD5, and CD99 were negative in the stromal lymphoid cell population. The tumor in one of the patients was associated with active pulmonary tuberculosis, and in another with anemia and splenomegaly of unknown etiology. None of the patients had clinical signs or history of myasthenia gravis or other autoimmune disorders. The present cases are interpreted as an unusual morphologic variant of spindle cell thymoma with prominent B-cell lymphoid hyperplasia. The possible significance of this phenomenon is discussed.
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PMID:Micronodular thymoma with lymphoid B-cell hyperplasia: clinicopathologic and immunohistochemical study of eighteen cases of a distinctive morphologic variant of thymic epithelial neoplasm. 1043 66

We report the unique case of a 52-year-old patient with atypical morphological features of gastric Langerhans cell histiocytosis. The man was admitted because of increasing upper abdominal pain and weight loss. The upper gastrointestinal endoscopy showed a submucous, hemispherical tumor of the stomach wall along the lesser curvature. The tumor was completely removed and the patient was discharged 11 days later. Two months later, he died at home. The cause of death is unknown, because the autopsy was denied by the relatives. Macroscopically, the stomach showed a 4.5 x 2.5 cm large, spherical tumor of the lesser curvature of the corpus, which infiltrated the perigastric omenta and lymph nodes, the distal pancreas and the glissonian liver capsule. The vast majority of neoplastic cells were intensely positive for S-100 and CD1a. Typical Birbeck granules could be identified in almost all cells. Cell nuclei analyzed by flow cytometry showed an aneuploid peak, a feature typically associated with malignant disease.
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PMID:Langerhans cell histiocytosis of the stomach with atypical morphological features. 1046 99

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

We have analyzed the presence of immature and mature dendritic cells (DCs) within adenocarcinoma of the breast using immunohistochemistry. Immature DCs were defined by expression of CD1a-, Langerin-, and intracellular major histocompatibility complex class II-rich vesicles. Mature DCs were defined by expression of CD83 and DC-Lamp. Breast carcinoma cells were defined by morphology and/or cytokeratin expression. We demonstrate two levels of heterogeneity of DCs infiltrating breast carcinoma tissue: (a) immature CD1a(+) DCs, mostly of the Langerhans cell type (Langerin(+)), were retained within the tumor bed in 32/32 samples and (b) mature DCs, CD83(+)DC-Lamp(+), present in 20/32 samples, are confined to peritumoral areas. The high numbers of immature DCs found in the tumor may be best explained by high levels of macrophage inflammatory protein 3alpha expression by virtually all tumor cells. Confirming the immature/mature DC compartmentalization pattern, in vitro-generated immature DCs adhere to the tumor cells, whereas mature DCs adhere selectively to peritumoral areas. In some cases, T cells are clustering around the mature DCs in peritumoral areas, thus resembling the DC-T cell clusters of secondary lymphoid organs, which are characteristic of ongoing immune reactions.
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PMID:In breast carcinoma tissue, immature dendritic cells reside within the tumor, whereas mature dendritic cells are located in peritumoral areas. 1056 17

Dendritic cells (DCs) are the most efficient antigen presenting cells (APCs) that initiate and modulate our internal immune responses in stimulating both B cells to produce various antibodies and T cells to control cell-mediated immunity. Such DCs can be classified into three groups based on their origin. One is the myeloid DCs originating from CD34+ stem cells that are further differentiated into CD14+ CD1a- phagocytotic, glass-adherent macrophages with the help of M-CSF, or into CD14- CD1a+, Birbeck granule containing LAG-1+ Langerhans cells by GM-CSF, TNF-alpha and TGF-beta 1 stimulation. The latter Langerhans cells appear to differentiate into DC1 as strong stimulators of T cells displaying large amounts of MHC-peptide complexes and co-stimulatory molecules, such as B7-1 and B7-2, after capturing antigens and migrating to a regional lymphoid organ. The second group is the lymphoid DCs originating from CD4+CD11c- cells, which differentiate into DC2 when cultured with IL-3. Third is the follicular dendritic cells (FDC) observed in lymphofollicules that capture foreign antigens with their Fc-receptor or complement-receptors and keep the antigens inside the follicules. DC1s secrete IL-12, which turns CD4 T cells into Th1 cells to induce cellular immunity, whereas DC2s favor production of Th2 cells to organize humoral immunity. Therefore, DCs appear to control our internal self-defense system. These unique features of DCs enable us to manipulate Th1 and Th2 activation selectively, and thus antigen-pulsed DCs are currently thought of as excellent tools to induce specific T cell immunity towards virus-infected cells or tumor cells.
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PMID:[Dendritic cells and tumor specific immunity]. 1063 93


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