title: Role of two-dimensional electrophoretic analysis in the diagnosis and characterization of IgD monoclonal gammopathy.
abstract: Over a period of 5 years, an isolated light chain (kappa = 9, lambda = 12) was detected in 21 sera by immunofixation electrophoresis. Further analysis with anti-delta- and anti-epsilon-specific antisera identified four delta heavy chains, all associated with a lambda light chain, and no epsilon heavy chains. For evaluation of the role of two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) in the diagnosis of IgD paraproteins, as a possible alternative or complement to immunofixation, IgD paraproteins were retrospectively analyzed by 2D-PAGE. Delta Heavy chains migrated to gel areas clearly distinguishable from other heavy chains alpha, gamma, or mu, and in a wide range of isoelectric points (pI: 5.4-8). In one serum, the monoclonal delta chain had a pI range comparable to that of albumin and was undetectable. However, all four delta chains were easily identified when analyzed from affinity-purified immunoglobulin fractions. These observations showed the following: 1) IgD paraproteins are not rare among apparently isolated monoclonal light chains detected by routine immunofixation, strongly confirming the need for further analysis with anti-delta antisera, before assumption of a light-chain disease. 2) 2D-PAGE analysis of affinity-purified immunoglobulin fractions allowed correct identification of IgD monoclonal gammopathies in all cases. 3) However, although 2D-PAGE analysis is now easy to perform, well standardized, and highly sensitive, this technique remains time-consuming and expensive, and does not appear suitable for routine practice as a first-line diagnostic procedure. 2D-PAGE should find its place as a complement to immunofixation and in the definitive demonstration, in selected ambiguous cases, of the clonal pattern of a suspected gammopathy at immunofixation.
authors.affiliation: Department of Medicine, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland.
authors.forename: F
authors.initials: F
authors.lastname: Spertini
authors.forename: J D
authors.initials: JD
authors.lastname: Tissot
authors.forename: N
authors.initials: N
authors.lastname: Dufour
authors.forename: C
authors.initials: C
authors.lastname: Francillon
authors.forename: P C
authors.initials: PC
authors.lastname: Frei
mesh_terms: D015153:Blotting, Western; D002846:Chromatography, Affinity; D015180:Electrophoresis, Gel, Two-Dimensional; D006801:Humans; D007072:Immunoglobulin D / Q000032:analysis* / Q000302:isolation & purification; D010265:Paraproteinemias / Q000175:diagnosis*
chemical_list: D007072:Immunoglobulin D