Current Status of Detecting Moncolonal Antibodies and Free Light Chains in Serum

Testing for abnormal immunoglobulins was based previously on serum electrophoresis and immunofixation only. In the last years, however, free light chain (FLC) testing in serum became one important pillar in the diagnosis and monitoring of multiple myeloma and related disorders such as amyloidosis, most of these diseases occurring in older patients. In particular, the ratio of κ FLCs to λ FLCs became pivotal in the diagnosis, monitoring, and rule-out of patients with suspected myeloma. The challenge of this serum testing is the heterogeneity of free light chains and other methodical issues of testing which challenge in particular FLC tests based on turbidimetry and nephelometry. The other challenges arise from the accumulation of FLC in serum due to the impaired excretion of FLC in patients with altered renal function - and renal function will decrease with age physiologically. Since elevated FLC will damage the kidneys, the establishment of reference ranges is challenging, and adequate reference ranges are necessary to obtain good discrimination between patients and normal („healthy“) subjects. This webinar will describe the laboratory tests currently used and will suggest methods to establish reference ranges that allow the optimized use of FLC assays.

 

 

Learning Objectives