title: Double (IgA kappa + IgG kappa) paraproteinaemia in a single patient: immunofluorescence evidence for a common plasma cell clone 'frozen' at the switch phase.
abstract: We present a patient with multiple myeloma and double (IgA kappa + IgG kappa) paraproteinaemia in the serum. Immunofluorescence analysis of bone marrow plasma cell with fluorochrome-conjugated goat antibodies specific for mu, delta, gamma or alpha immunoglobulin heavy chain and kappa or lambda light chains revealed the presence of a plasma cell clone synthesizing simultaneously gamma, alpha and kappa chains. A minority of plasma cells synthesized gamma or alpha chains separately. Moreover, in the patient's peripheral blood, a few cells with the morphology of lymphoplasmoblasts and simultaneously positive for gamma, alpha and kappa chains were also detected. These results indicate that in this patient, the neoplastic plasma cell clone was 'frozen' at the differentiative step of the switch from IgG to IgA synthesis.
mesh_terms: D000368:Aged; D005455:Fluorescent Antibody Technique; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis*; D007074:Immunoglobulin G / Q000032:analysis*; D007145:Immunoglobulin kappa-Chains / Q000032:analysis*; D008297:Male; D009101:Multiple Myeloma / Q000276:immunology*; D010950:Plasma Cells / Q000276:immunology
chemical_list: D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007145:Immunoglobulin kappa-Chains