Human B Cells: Differentiation and Neoplasia

Abstract
Human B cells differentiate from stem cells to immunoglobulin secreting plasma cells and during this course a series of discrete phases can be recognised. These stages are mirrored in the various malignancies that arise from the B cell lineage and therefore a knowledge of the cellular and molecular events in B cell differentiation are important for a full appreciation of B cell neoplasia. This review intends to provide an overview of human B cell differentiation and the related clinical spectrum of B cell leukaemia and lymphoma. The review will discuss the phenotype of B cells utilizing the expression of surface immunoglobulin and the expression of molecules recognised by monoclonal antibodies including recent cluster designations that are B cell restricted. Immunoglobulin genes and the process of rearrangement which they undergo will be considered as well as molecular defects recognised by the Southern blotting technique. Finally, the most commonly encountered phenotype patterns from each of the recognized entities within the spectrum of B cell neoplasia will be described.