Summary
Introduction. Multiple myeloma is a malignant hematologic disorder which is described by the clonal expansion of plasma cells in the bone marrow. The incidence of this disease is increasing every year all over the world, especially in the United States, Australia and Europe. M– protein is considered to be one of the main markers for the disease monitoring in patients during therapy. However, after the treatment of patients with chemotherapy and especially autologous bone marrow transplantation, oligoclonal bands can be observed in serum electrophoresis; their diagnostic significance and implications are not fully elucidated. The purpose of this paper is to review the diagnostic significance and importance of serum oligoclonal bands, to propose guidelines for their interpretation and to present a clinical case demonstrating this issue.
Material and methods. Blood serum samples from a patient with multiple myeloma were analysed by capillary electrophoresis (Sebia, France) and immunofixation (Sebia, France) methods. The data obtained from studies before and after autologous bone marrow transplantation were analysed.
Results. During electrophoresis studies, it was found that 5 months after the second autologous bone marrow transplantation the original monoclonal is no longer present, but intense and prominent IgG kappa and lambda oligoclonal bands were observed. It was identified that the immunoglobulin isotype and electrophoretic mobility of these bands have changed, thus they are result of oligoclonal regeneration.
Conclusions. Serum oligoclonal bands are a transient condition, which is associated with longer progression- free survival and overall survival after autologous bone marrow transplantation. The appearance of these bands could be used as a marker of normal immune system activity and regeneration. In order to prevent false positive interpretation, it is crucial to properly evaluate electrophoresis assays. It is necessary to compare electrophoretic serum protein profiles before and after the treatment and to precisely identify the patient’s original M-protein.
