[Evaluation of the new Hevylite IgA assay for the diagnosis and follow-up of monoclonal gammopathies].

Fiche publication


Date publication

mars 2013

Auteurs

Membres identifiés du Cancéropôle Est :
Pr BASTIE Jean-Noël, Dr CAILLOT Denis


Tous les auteurs :
Lakomy D, Lemaire-Ewing S, Denimal D, Bastie JN, Lafon I, Caillot D

Résumé

Multiple myeloma diagnosis and follow-up are based on monoclonal protein measurement. The estimation of monoclonal immunoglobulin production requires serum protein electrophoresis, immunoelectrophoresis and free light chain assay. However these classical assays have some limitations. Hevylite IgA (Binding Site) is a new nephelometric/turbidimetric assay allowing the IgA kappa and IgA lambda measurement. The aim of this study was to determine the performance of this assay, for the diagnosis and follow-up of myeloma patients at different stages. Sixty seven frozen sera from 26 patients were assayed. Total IgA, IgA kappa, IgA lambda concentrations, serum protein electrophoresis and serum immunofixation were performed at diagnosis and during follow-up. All myeloma patients had an abnormal IgA kappa/IgA lambda ratio at diagnosis. During disease monitoring, the IgA kappa or IgA lambda concentrations correlated well with the electrophoretic estimation of the monoclonal spike and the values of total IgA. Hevylite test was more sensitive than serum protein electrophoresis and provided numerical and reproductible assessment of the monoclonal and non-monoclonal isotype. The IgA kappa/IgA lambda ratio allowed early prediction of disease relapse. Hevylite is an interesting assay especially when the monoclonal IgA comigrates on electrophoresis with normal proteins making impossible a reliable densitometric estimation. Hevylite might become an important assay in the biological exploration of gammopathies.

Référence

Ann Biol Clin (Paris). 2013 Mar-Apr;71(2):157-63