title: Autoantibody activity of the immunoglobulin secreted by a follicular B-cell lymphoma.
abstract: In patients with B-cell lymphoma, only in rare cases a secreted paraprotein is found, and in very few of them an associated autoantibody activity has been demonstrated. Here we report the case of a patient with a low-grade B-cell lymphoma with a serum biclonal paraprotein (G,M)lambda and severe erythroblastopenia. Indirect immunofluorescence studies of total serum revealed cytoplasmic (Hep-2 cells) and extracellular matrix (rat tissue sections) staining, suggestive of a new specificity. After gel filtration of serum samples, only the IgM-containing fraction showed the same pattern of staining. Tumor-derived hybridomas expressed an unmutated V3-11 gene identical to that found in tumor samples and secreted an IgM immunoglobulin endowed with the same reactivity, which confirms the tumoral origin of the tissue-reactive protein. The results suggest a link between the autoimmune condition in this patient and the novel specificity displayed by the tumor-derived immunoglobulin.
authors.affiliation: Department of Immunology, Hospital Clínica Puerta de Hierro, Madrid, Spain. yvelise.barrios@immun.lth.se
authors.forename: Y
authors.initials: Y
authors.lastname: Barrios
authors.forename: A
authors.initials: A
authors.lastname: Plaza
authors.forename: R
authors.initials: R
authors.lastname: Cabrera
authors.forename: F
authors.initials: F
authors.lastname: Díaz-Espada
mesh_terms: D000328:Adult; D000595:Amino Acid Sequence; D000818:Animals; D000912:Antibodies, Neoplasm / Q000097:blood / Q000276:immunology*; D000918:Antibody Specificity; D001323:Autoantibodies / Q000097:blood / Q000276:immunology*; D001483:Base Sequence; D002460:Cell Line; D019084:Fluorescent Antibody Technique, Indirect; D005803:Genes, Immunoglobulin; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D007075:Immunoglobulin M / Q000097:blood / Q000276:immunology; D016393:Lymphoma, B-Cell / Q000276:immunology*; D008224:Lymphoma, Follicular / Q000276:immunology*; D008297:Male; D008969:Molecular Sequence Data; D010266:Paraproteins / Q000276:immunology*; D051381:Rats; D014407:Tumor Cells, Cultured
chemical_list: D000912:Antibodies, Neoplasm; D001323:Autoantibodies; D007143:Immunoglobulin Heavy Chains; D007075:Immunoglobulin M; D010266:Paraproteins