Extra

CD23 is a broadly expressed molecule whose impotance lies in its value in distinguishing between CLL (consistent expression) and MCL (infrequent expression).

However, CD23 is not a CLL-specific marker, and is also expressed on other haematological and lymphoma cell types.

normal expression and function

CD23 is a low-affinity receptor for IgE that is involved in antigen capture and presentation. It affects B-cell growth and differentiation and the activation of monocytes. It is expressed on activated B-cells, but also platelets eosinophils activated macrophages and follicular dendritic cells.

other relevant information

When CD23 is expressed by MCL the cases may have a more indolent course and an improved outcome.

diagnostic role

• CD23 is most frequently used to distinguish between CLL and MCL but this difference is not absolute: CD23 is expressed by the vast majority (90% of typical CLL patients), and is generally absent in MCL although it is detected in around 10% of cases where its expression may be bright.
• CD23 may also be expressed by other B-lymphoproliferative disorders although at lower frequency:including lymphoplasmacytic lymphoma, marginal zone lymphoma or follicular lymphoma.

summary tables

1. expression by acute leukaemias and by haematogones file rare.png pro-b all link flow cytometry key file rareu82epng early pre-b all link flow cytometry key file rareu82epng pre-b all link flow cytometry key file rareu82epng early b all link flow cytometry key file rareu82epng pro-t all link flow cytometry key file rareu82epng mature-t all link flow cytometry key file possu82epng aml link flow cytometry key file rareu82epng haemato-gones link flow cytometry key *may be expressed in aml with monocytic differentiation

2. expression by b-lymphoproliferative disorders file hiu82epng frame cll link flow cytometry key file rareu82epng pll link flow cytometry key file possu82epng mcl link flow cytometry key file modu82epng fl link flow cytometry key file possu82epng hcl link flow cytometry key file possu82epng hclv link flow cytometry key file rareu82epng mzl link flow cytometry key file rareu82epng lpl link flow cytometry key file rareu82epng pcs link flow cytometry