Immunoglobulin heavy and light chain isotypes in multiple myeloma patients.

The frequency of expression of immunoglobulin (Ig) light and heavy chain isotypes was analyzed in myeloma proteins (M-proteins) from sera of 40 Indian patients with clinically established multiple myeloma. Patients samples were screened by a combination of electrophoresis, immunoelectrophoresis (IEP) and ELISA techniques in this study. We found that majority of the myeloma proteins (58%) were of the IgG isotype followed by IgA (24%) and biclonal gammopathy associated with IgG and IgA (5%). Both kappa and lambda light chains were associated with the heavy chain isotypes. We recommend the triangular combination for detection of M-proteins and biclonal gammopathy of cancerous plasma cells as biomarkers for diagnosis of myeloma.