Electrophoretical distribution of serum monoclonal protein and underlying causes. Data from a referral center in Mexico

Abstract

Background: Monoclonal gammopathies are a group of disorders characterized by an overproduction of monoclonal immunoglobulin. Detection and quantification of monoclonal components using serum protein electrophoresis (SPE) for screening is the initial step in the evaluation of monoclonal gammopathies. This study aimed to describe the electrophoretic patterns of Hispanic patients with suspected monoclonal gammopathy in our hematological disease referral center. Material and methods: All SPE tests performed between January 2013 and November 2017 at the Hematology Service Laboratory in the “Dr. Jos Eleuterio Gonz lez” University Hospital were collected in which monoclonal gammopathy was suspected. Age, gender, and diagnosis, when available, were recorded. We described the immunoelectrophoretic patterns by SPE according to the type of gammopathy. Results: A total of 1461 SPE results were collected. Sixty-four percent of the patients had an abnormal electrophoretic pattern, 19.5% a polyclonal gammopathy, and 44.7% exhibited at least one monoclonal component (monoclonal gammopathy). The isotype most found was IgG in 108 (52.9%), followed by IgA in 40 (19.6%) serum samples, and kappa was the most frequently involved light chain. In 86% of patients, we were able to establish a definitive diagnosis. The most common monoclonal gammopathy was multiple myeloma in 89%, and only one case of monoclonal gammopathy of undetermined significance was diagnosed. Conclusion: Our group of patients exhibits different electrophoretic patterns from previous reports. Multiple myeloma is the most common monoclonal gammopathy, and monoclonal gammopathy of undetermined significance possibly goes underdiagnosed.

Keywords

• Monoclonal gammopathies. Serum protein electrophoresis. Multiple Myeloma. Monoclonal gammopathy of undetermined significance.