CD52

CAMPATH-1 antigen, also known as is_associated_with::cluster of differentiation 52 (CD52), is a is_associated_with::glycoprotein that in humans is encoded by the CD52 is_associated_with::gene.

CD52 is present on the surface of mature is_associated_with::lymphocytes, but not on the is_associated_with::stem cells from which these lymphocytes were derived. It also is found on is_associated_with::monocytes and is_associated_with::dendritic cells. Further, it is found within the male genital tract and is present on the surface of mature is_associated_with::sperm cells.

CD52 is a is_associated_with::peptide of 12 amino acids, anchored to is_associated_with::glycosylphosphatidylinositol (GPI). Since it is highly negatively charged and present on sperm cells and lymphocytes, it has been conjectured that its function is anti-adhesion, allowing cells to freely move around.

CD52 binds the ITIM (is_associated_with::Immunoreceptor tyrosine-based inhibitory motif)-bearing sialic acid-binding lectin is_associated_with::SIGLEC10.

Clinical significance
It is associated with certain types of is_associated_with::lymphoma.

It is the protein targeted by is_associated_with::alemtuzumab, a is_associated_with::monoclonal antibody used for the treatment of is_associated_with::chronic lymphocytic leukemia. A phase III trial into treatment of relapsing-remitting Multiple Sclerosis showed a reduction in relapse rate, but no statistically significant reduction in accumulated disability, when used as a first-line therapy. However, a sister study looking at patients in whom relapses had occurred despite treatment with interferon beta or glatiramer demonstrated reduction in both relapse rate and accumulated disability. 20% patients randomised to interferon beta 1a had "sustained accumulation of disability" compared with 13% in the alemtuzumab group. .