Background: Most patients with multiple myeloma have an abnormal band in the gamma region of protein electrophoresis.
Aim: To correlate the clinical diagnosis with patterns of protein electrophoresis.
Methods: Retrospective analysis of all protein electrophoresis or immunoglobulin quantification requested during 1992 and review of clinical charts of patients.
Results: During 1992, 553 protein electrophoresis were requested. Of these, 344 were repetitions and 209 came from patients seen for the first time. Among the latter, we found a monoclonal component in 40. Of these 40 patients, 35 had a multiple myeloma, one had a plasmocytoma and four a non-Hodgkin lymphoma. Fourteen patients with diagnosis of myeloma did not have a monoclonal component in protein electrophoresis. These figures resulted in a 71% sensitivity and 97% specificity for monoclonal components in the diagnosis of multiple myeloma. The monoclonal component of patients with myeloma was characterized as IgG in 29 (60%), IgA in 5 (10%) and IgM in one.
Conclusions: A monoclonal component present in a protein electrophoresis has a high diagnostic accuracy for multiple myeloma.