CD20 (SP32)

Anti-CD20 (pan B-cell) reacts with a membrane antigen that is present in B-cells as this epitope is acquired late in the pre-B-cell stage of maturation and remains on cells throughout most of the differentiation process, although it is lost at the plasma cell stage. This antibody recognizes Reed-Sternberg cells, predominant in classic Hodgkin’s disease, in approximately 20% of cases, and approximately half of lymphoblastic lymphoma/leukemias.1-4 Since no staining of histiocytes or plasma cells has been observed and CD20 has rarely been detected in T-cell malignancies, it is a dependable marker of B-cell lymphomas.5 Anti-CD20 does not cross-react with non-hematopoetic neoplasms.