title: Expression of CD52 on plasma cells in plasma cell proliferative disorders.
abstract: Multiple myeloma (MM) and primary systemic amyloidosis (AL) remain incurable disorders, and new treatments targeted to the malignant plasma cells are needed. Alemtuzumab is a humanized monoclonal antibody to CD52 and has activity in chronic lymphocytic leukemia. We examined the CD52 expression on CD45+ and CD45- plasma cell populations to evaluate the potential for using alemtuzumab for these disorders. Bone marrows from 61 patients (29 AL, 23 MM, and 9 MGUS [monoclonal gammopathies of undetermined significance]) were studied using 3-color (CD38/45/52) flow cytometry. Among those with MGUS, MM, and AL, 67%, 52%, and 35%, respectively, were positive for CD52 expression. The CD52 expression was predominantly confined to the clonal CD38+/CD45+ plasma cell fraction with median expression of 68%, 88%, and 82% in MGUS, MM, and AL, respectively, compared with 18%, 6%, and 9% among the CD45- plasma cell population. Clinical trials are warranted in these diseases to learn the therapeutic benefit of anti-CD52 immunotherapy.
authors.affiliation: Department of Internal Medicine, Division of Hematology, Mayo Clinic and Mayo Foundation, Rochester, MN 55905, USA.
authors.forename: Shaji
authors.initials: S
authors.lastname: Kumar
authors.forename: Teresa K
authors.initials: TK
authors.lastname: Kimlinger
authors.forename: John A
authors.initials: JA
authors.lastname: Lust
authors.forename: Kathleen
authors.initials: K
authors.lastname: Donovan
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Witzig
mesh_terms: D000074323:Alemtuzumab; D000911:Antibodies, Monoclonal / Q000627:therapeutic use; D061067:Antibodies, Monoclonal, Humanized; D000912:Antibodies, Neoplasm / Q000627:therapeutic use; D015703:Antigens, CD / Q000032:analysis*; D000951:Antigens, Neoplasm / Q000032:analysis*; D001853:Bone Marrow / Q000276:immunology / Q000473:pathology; D000074301:CD52 Antigen; D005434:Flow Cytometry; D006023:Glycoproteins / Q000032:analysis*; D006801:Humans; D016130:Immunophenotyping; D008998:Monoclonal Gammopathy of Undetermined Significance / Q000276:immunology / Q000473:pathology; D009101:Multiple Myeloma / Q000276:immunology / Q000473:pathology; D010265:Paraproteinemias / Q000276:immunology / Q000473:pathology*; D010950:Plasma Cells / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000912:Antibodies, Neoplasm; D015703:Antigens, CD; D000951:Antigens, Neoplasm; D000074301:CD52 Antigen; C000613862:CD52 protein, human; D006023:Glycoproteins; D000074323:Alemtuzumab