CD1a is a group-1 member of the CD1 family of major histocompatibility (MHC)-like glycoproteins.
CD1a is T cell surface antigen important in dendritic cell presentation of glycolipids and lipopeptide antigens.
CD1a may activate intrathyroidal T cells in Hashimoto’s thyroiditis and Grave’s disease (J Immunol 2005;174:3773)
Expression in normal cells
Langerhans cells in normal skin
CD1a+ cortical thymocytes in normal thymus
immature dendritic cells (Langerin-, CD86-, HLA-DR low, CD40-low)
Expression in tumors
Langerhans cell histiocytosis
T-cell acute lymphoblastic leukemia (T-LLA)
myeloid leukemias
mycosis fungoides (variable)
almost all cutaneous T cell lymphomas, T-ALL
Barrett metaplasia of esophagus
monocytes in most sickle cell anemia patients
Negative staining
normal B cells
dendritic cells in most cutaneous B cell lymphomas
histiocytic lymphoma / sarcoma
histiocytoma
follicular dendritic cells
follicular dendritic cell tumor
interdigitating dendritic cells
interdigitating dendritic cell sarcoma
dendritic cell neurofibroma
juvenile xanthogranuloma
sinus histiocytosis with massive lymphadenopathy
Erdheim-Chester disease