title: Mitogenic stimulation of malignant B cells Waldenstrøm's macroglobulinaemia: secretion of monoclonal IgM by in vitro-induced plasmablasts.
abstract: The monoclonal B cells present in the blood of three patients with Waldenstrøm's macroglobulinaemia were analysed according to phenotype and function. As a marker for the monoclonal nature of the detected immunoglobulin (Ig) molecules, the kappa/lambda-ratio (two patients) or the presence of idiotypic (Id) determinants (one patient) were used. With double immunofluorescence it was shown that the neoplastic blood B cells were heterogeneous in respect to maturation stage. In addition to B cells carrying membrane bound IgM and IgD (mIgM+/IgD+), both mIgM+/IgD- and cytoplasmic IgM+ blastoid cells could be detected in the blood of the patients. This heterogeneity was also reflected in the responses of the monoclonal B cells upon stimulation with mitogens and T cell factors. B blastoid cells and IgM secretion could be induced after in vitro culture in the presence of Staphylococcus aureus, Pokeweed mitogen or a combination of both mitogens. It was shown that also T cell factors were effective in inducing monoclonal B cell differentiation.
authors.forename: A C
authors.initials: AC
authors.lastname: Bloem
authors.forename: M A
authors.initials: MA
authors.lastname: Chand
authors.forename: B
authors.initials: B
authors.lastname: van Camp
authors.forename: E J
authors.initials: EJ
authors.lastname: Bast
authors.forename: R E
authors.initials: RE
authors.lastname: Ballieux
mesh_terms: D001402:B-Lymphocytes / Q000276:immunology*; D002478:Cells, Cultured; D002999:Clone Cells; D006801:Humans; D007075:Immunoglobulin M / Q000032:analysis*; D007376:Interleukin-2 / Q000276:immunology; D008213:Lymphocyte Activation; D010641:Phenotype; D010950:Plasma Cells / Q000276:immunology*; D011043:Pokeweed Mitogens / Q000494:pharmacology; D013211:Staphylococcus aureus / Q000276:immunology; D008258:Waldenstrom Macroglobulinemia / Q000276:immunology*
chemical_list: D007075:Immunoglobulin M; D007376:Interleukin-2; D011043:Pokeweed Mitogens