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)

Canine cutaneous histiocytoma (CCH) is a common, benign neoplasm of the dog. Histiocytomas most commonly occur as solitary lesions that undergo spontaneous regression. The age-specific incidence rate for histiocytomas drops precipitously after 3 years, although histiocytomas occur in dogs of all ages. Langerhans cells (LCs) in humans and dogs express abundant major histocompatibility complex class II molecules and a variety of leukocyte antigens characteristic of dendritic cell differentiation including CD1a, CD1b, CD1c, and CD11c. The immunophenotype of CCH resembled that of cutaneous LCs by virtue of the expression of CD1 molecules (CD1a, -b, and -c), CD11c, and major histocompatibility complex class II. Furthermore, histiocytoma cells had a tropism for epidermis, which was also consistent with an epidermal LC lineage. The expression of adhesion molecules such as CD11b (variable), CD44, CD54 (ICAM-1), and CD49d (VLA-4) in CCH indicated that the infiltrating cells had some of the characteristics of activated LCs, as these molecules are not expressed by normal, resting canine epidermal LCs. CCH did not express Thy-1 or CD4. Thy-1 expression is a characteristic of human and canine dermal dendrocytes, which are perivascular dendritic antigen-presenting cells closely related to epidermal LCs. CD4 expression is prevalent in human LC histiocytosis, and in this respect CCH differed from human LC histiocytosis. Here we demonstrate that CCH is a localized form of self-limiting LC histiocytosis, which predominantly expresses an epidermal LC phenotype. CCH occurs as solitary or, less commonly, as multiple cutaneous nodules or plaques, which rarely may extend beyond the skin to local lymph nodes. Regression of CCH occurs spontaneously in the vast majority of cases in primary and secondary sites, and is mediated by CD8+ alpha beta T cells. The high frequency of CCH within the general canine population offers the potential that the dog may provide an interesting model system to further the understanding of LC proliferative disorders, particularly the self-limiting, cutaneous form of human LC histiocytosis.
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PMID:Canine cutaneous histiocytoma is an epidermotropic Langerhans cell histiocytosis that expresses CD1 and specific beta 2-integrin molecules. 862 37

We describe a widespread papular eruption in a 5-year-old girl with rheumatic fever. Histological examination revealed a dense histiocytic infiltration in the dermis. On immunohistochemical studies, the cells were positive for vimentin, CD68, MAC387, alpha1-antichymotrypsin and lysozyme, but negative for CD1a and S-100 protein. Electron microscopic studies showed no Birbeck granules in their cytoplasm. A diagnosis of generalized eruptive histiocytoma of childhood was established. The skin lesions completely disappeared within 8 months.
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PMID:Generalized eruptive histiocytoma of childhood associated with rheumatic fever. 1052 34

This report describes the clinicopathologic, immunohistochemical, and ultrastructural features of a benign fibrous histiocytoma of 3 years' duration situated on the posterior right arm of a 17-year-old woman. To our knowledge, this is the first published description of an association between the histologic features of benign fibrous histiocytoma with proliferating dermal dendrocytes and solid clusters of indeterminate cells and inflammatory infiltrate containing numerous eosinophils. Cell type identification was confirmed by immunohistochemical demonstration of positivity of indeterminate cells for CD1a and S-100 protein, by absence of Birbeck granules in electron microscopy study, and by positivity of fibroblast-like cells for factor XIIIa and negativity for CD34. Mitosis or cytologically atypical cells were absent. The MIB1-measured proliferative index of the tumor cells was less than 5% in spindle cells and approximately 15% in indeterminate cells. Possible pathogenic pathways are discussed that could account for divergent differentiation or a combination of neoplasms of different lineages.
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PMID:Benign fibrous histiocytoma with indeterminate cells and eosinophils: collision, differentiation, or involution? 1516 15

Canine mast cell tumours (MCTs) may be graded microscopically for prognostic purposes. Grade I (well-differentiated) and grade II (intermediate differentiation) tumours have an abundance of metachromatic granules within the cytoplasm; however, grade III (poorly differentiated) MCTs may be difficult to diagnose as they frequently have fewer discernable granules. Herein we report that a cross-reactive anti-human CD1a monoclonal antibody (clone O10) may be used in immunohistochemistry to identify canine MCTs of all grades. The antibody was applied to tissue sections from 48 canine MCTs of different histological grades. Serial sections from each tumour were stained with toluidine blue and safranin O to compare diagnostic sensitivity. All MCTs were labelled positively by the CD1a antibody, but histochemical staining was often equivocal and identification of mast cells was extremely difficult in some cases. This antibody did not label neoplastic cells in cases of canine histiocytoma, plasmacytoma or amelanotic melanoma; therefore, the reagent may be a valuable marker for the diagnosis of canine MCTs, especially those tumours of histological grade III.
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PMID:Immunohistochemical application of an antibody specific for human CD1a to the diagnosis of canine mast cell tumour. 1860 42

A newborn baby boy was referred to the Paediatric Dermatology Unit with a solitary asymptomatic nodule overlying his right nasolabial fold. Complete physical examination, full blood count, serum chemistry, liver function tests and baseline imaging were unremarkable. Histopathological examination showed an atypical dermal infiltrate of mononuclear cells that stained positive with CD1a and S100. A diagnosis of congenital solitary Langerhans cell histiocytoma was made. The lesion completely resolved by 4 months of age. The baby is now 15 months old and repeat systemic evaluation has remained normal.
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PMID:A case of congenital solitary Langerhans cell histiocytoma. 2160 85

Generalized eruptive histiocytoma is considered an extremely rare subtype of non-Langerhans cells histiocytosis. In the literature, there are few reports of this disease that mainly affects adults. In this report, we present a case of generalized eruptive histiocytoma in an elderly patient who had presented symptoms for over two months. Multiple erythematous papules, asymptomatic and symmetrically distributed were observed on the trunk and limbs. Histological examination showed a dense mononuclear cell dermal infiltrate. In the immunohistochemical analysis, the cells were CD68 positive, but CD1a, S100 and CD34 negative. A diagnosis of generalized eruptive histiocytoma was established. The aim of our paper is to report a case of a very rare disease, whose subtype and affected age group are even more unusual.
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PMID:Generalized eruptive histiocytoma: a rare disease in an elderly patient. 2353 13

Generalized eruptive histiocytoma is a rare benign skin disorder with less than 50 cases reported world-wide. It belongs to type IIb of histiocytoses. The histiocytic cells are CD68 positive but lack other markers like CD1a or S100. We report on a 60-year-old male patient with generalized eruptive histiocytoma treated successfully by PUVA combined with topical corticosteroids.
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PMID:Generalized eruptive histiocytoma in adult patient. 2601 60

Langerhans cell (LC) histiocytoma is a neonatal tumor that often consists of a single, ulcerated nodule. Systemic involvement is rare, and LC histiocytoma is considered to be a variant of congenital, self-healing LC histiocytosis (also referred to as Hashimoto-Pritzker disease). In view of its low prevalence, LC histiocytoma is not always diagnosed in a clinical examination and requires histological confirmation. Furthermore, the histological and molecular features of LC histiocytoma have not been well characterized. Here, we report on 6 cases of this rare disease and review the corresponding literature. LC histiocytoma differs from classical self-healing LC histiocytosis with regard to the pathological features; we found that LC histiocytoma was associated with massive infiltration by histiocytes of various sizes and shapes (although often large) throughout the dermis and the superficial subcutis. Epidermotropism was rare, mitotic figures were not inconspicuous, and necrotic or calcified areas were often present. Immunohistochemical assessment revealed a mixture of different types of histiocytes (with CD1a CD207, CD1a CD207, and CD1a CD207 CD163 cells). Genetic testing was performed in 5 cases; it revealed a BRAF mutation (p.V600E and p.485_490delinsF) in 2 cases, a HRAS mutation (p.T58I) in 1 case, a combination of 2 PTEN mutations in another case (p.I224M and p. R234W), and no mutations in the fifth case. All the lesions regressed spontaneously, and none recurred during follow-up.
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PMID:Langerhans Cell Histiocytoma: A Benign Histiocytic Neoplasm of Diverse Lines of Terminal Differentiation. 3025 93