CD1a

CD1a

a type I transmembrane protein found on thymocytes, Langerhans cells, brain astrocytes, and dermal cells that is involved in nonclassical antigen presentation or is a receptor for an undefined ligand or hormone; expressed in patients with T-cell acute lymphoblastic leukemia, histiocytosis X, and thymomas.
References in periodicals archive ?
Cells in LCH express CD1a and ultrastructurally, Birbeck granules.
Immunohistochemical staining for S-100 protein and CD1a confirmed that the histiocytic cells were Langerhans' cells.
Mast cells, however, lack the typical nuclear grooves seen in Langerhans cells and do not react with the Langerhans cell markers S100, CD1a, fascin, and Langerin.
Langerhans cells stain for S100 protein and CD1a but are generally negative for CD45.
4) Moreover, in all of our patient's biopsies, the immunohistochemical studies were consistent with RDD, including CD68 and S100 protein labeling of histiocytes and lack of CD1a expression.
The SHML histiocytes are positive for S100 protein and negative for CD1a by immunohistochemistry.
Terminal deoxynucleotidyl transferase, CD34, and CD1a each suggest an immature T-lymphoid process, with TdT the most likely to be present (Figure 3, d).
Other positive immunostaining patterns are reported with CD1a, CD10, desmin, S100 protein, and caldesmon.
Tumors derived from Langerhans cells, such as Langerhans cell sarcoma, typically stain for CD1a and S100.
A second panel of immunostains showed negativity for CD34, terminal deoxynucleotidyl transferase, myeloperoxidase, muramidase (lysozyme), CD1a, and desmin, prompting consideration of a microphthalmia-associated transcription factor-positive, CD117-positive metastatic melanoma that had otherwise lost antigen expression.