title: Ultrastructural aspects of crystal-like inclusions in a case of IgA plasma cell proliferation.
abstract: A case of apparently benign plasma cell proliferation is described. Needle-like paracrystalline inclusions were observed in numerous plasma cells outside the cisternae of the rough endoplasmic reticulum. They had a dense protein core surrounded by a layer of carbohydrate. They were found only in plasma cells secreting IgA-kappa immunoglobulin, but did not react with labelled specific antisera. A small amount of paraprotein IgA-kappa was found in the serum but no Bence-Jones protein could be detected in the urine. These observations suggest that these plasma cells synthesize normal IgA immunoglobulin and accumulate abnormal protein in the form of paracrystalline inclusions.
mesh_terms: D000368:Aged; D001853:Bone Marrow / Q000648:ultrastructure*; D001854:Bone Marrow Cells; D002455:Cell Division; D003459:Crystallins; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D006942:Hypergammaglobulinemia / Q000097:blood* / Q000276:immunology; D007070:Immunoglobulin A / Q000032:analysis; D007137:Immunoglobulin alpha-Chains / Q000032:analysis; D007145:Immunoglobulin kappa-Chains / Q000032:analysis; D002479:Inclusion Bodies / Q000648:ultrastructure*; D008854:Microscopy, Electron; D010950:Plasma Cells / Q000276:immunology / Q000648:ultrastructure
chemical_list: D003459:Crystallins; D007070:Immunoglobulin A; D007137:Immunoglobulin alpha-Chains; D007145:Immunoglobulin kappa-Chains