CAMPATH-1 antigen (CD52) (CD52)

CAMPATH-1 antigen, commonly known as CD52, is a small, heavily glycosylated protein anchored to the cell membrane via a glycosylphosphatidylinositol (GPI) linkage [1, 3, 5]. It is widely expressed on the surface of mature lymphocytes (T and B cells), monocytes, macrophages, and natural killer cells, as well as in the male reproductive tract [1, 9]. While its exact physiological function remains partially elusive, CD52 is known to participate in immune regulation, lymphocyte migration, and signal transduction, often acting as an inhibitory ligand for the SIGLEC10 receptor [1, 5, 8]. In clinical practice, CD52 is the primary target of the humanized monoclonal antibody alemtuzumab, which induces rapid and profound depletion of CD52-positive cells through antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) [6, 11, 13]. This target is highly relevant in the treatment of relapsing-remitting multiple sclerosis and B-cell chronic lymphocytic leukemia [1, 3, 11]. However, therapeutic modulation of CD52 is associated with significant safety concerns, including severe infusion-related reactions, prolonged lymphopenia, and an increased risk of secondary autoimmune disorders [5, 11].

Other names

CDw52Cambridge pathology 1 antigenEpididymal secretory protein E5Human epididymis-specific protein 5HE5CD52 moleculeEDDM5

Antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) resulting in rapid depletion of CD52-expressing lymphocytes [5, 6, 11].