Abstract The
diagnosis of
Multiple Myeloma is a challenge to the
physician due to the non-specific symptoms (
anemia,
bone pain and
recurrent infections) that are commonplace in the
elderly population. However,
early diagnosis is associated with less severe
disease, including fewer
patients presenting with
acute renal injury,
pathological fractures and severe
anemia. Since 2006, the
serum free
light chain test Freelite® has been included alongside standard
laboratory tests (
serum and
urine protein electrophoresis, and
serum and
urine immunofixation) as an
aid in the identification of monoclonal
proteins, which are a cornerstone for the
diagnosis of
Multiple Myeloma. The
serum free
light chain assay recognizes the
light chain component of the
immunoglobulin in its free form with high
sensitivity. Other assays that
measure light chains in the free and intact
immunoglobulin forms are sensitive, but unfortunately, due to the nomenclature used, these assays (total
light chains) are sometimes used in place of the free
light chain assay. This
paper reviews the available
literature comparing the two assays and tries to clarify hypothetical limitations of the total assay to detect
Multiple Myeloma. Furthermore, we elaborate on our study comparing the two assays used in 11
Light Chain
Multiple Myeloma patients at presentation and 103
patients taken through the
course of their
disease. The aim of this article is to provide a clear discrimination between the two assays and to provide information to
physicians and
laboratory technicians so that they can utilize the International Myeloma Working Group guidelines.