CD1a (EP3622)

CD1a is a non-polymorphic major histocompatibility complex class I-related cell surface glycoprotein and is expressed in association with β- macroglobulin. In normal tissues the CD1a antibody reacts with cortical thymocytes, Langerhans cells, interdigitating dendritic cells, and rare antigen-presenting cells of the lymph node.1-3 Anti-CD1a also reacts with Langerhans cell histiocytosis,3 and a subset of pre-T lymphoblastic lymphoma/leukemia (cortical T LBL/L).4,5 When combined with S100 and CD68, CD1a has been reported to be very useful in distinguishing Rosai-Dorfman disease from other histiocytic diseases.