Lymphocyte antigen CD52 (CD52)

Lymphocyte antigen CD52 is a small, highly glycosylated, glycosylphosphatidylinositol-anchored cell-surface glycoprotein abundantly expressed on mature lymphocytes and also present on monocytes and dendritic cells, with lower levels on neutrophils and little to no expression on hematopoietic stem cells; it is also produced in the male genital tract and present on mature sperm cells. CD52’s exact physiological role is not fully defined; evidence supports roles in lymphocyte transendothelial migration, T-cell costimulation/activation, potential anti-adhesion properties, and interaction with the inhibitory lectin receptor SIGLEC10 via its ITIM pathway. Clinically, CD52 is an established therapeutic target: the humanized anti-CD52 antibody alemtuzumab depletes CD52-positive lymphocytes via ADCC and CDC and is used in chronic lymphocytic leukemia, in multiple sclerosis (relapsing–remitting) as immune reconstitution therapy, and in transplantation settings for lymphocyte depletion, with ongoing exploration in other hematologic malignancies (e.g., certain T/NK-cell neoplasms and FLT3-ITD–associated leukemias). Because CD52 expression can vary across diseases and patients, flow cytometric assessment of surface CD52 is recommended before initiating anti-CD52 therapy and can be used to monitor therapeutic targeting.

Other names

CAMPATH-1 antigenCluster of differentiation 52CAMPATH-1CD52 antigen

Antibody-dependent cellular cytotoxicity (ADCC) against CD52-positive cells; Complement-dependent cytotoxicity (CDC); Antibody-mediated lymphocyte depletion leading to immunosuppression