Myeloma screening with turbidimetric immunoassays has limited value

06-16-2006

Automated turbidimetric immunoassays have limited utility in multiple myeloma screening.

"Recently, turbidimetric immunoassays for detecting and quantifying kappa and lambda free light chains (FLC) have become available and are promoted as being more sensitive than immunofixation electrophoresis (IFE) in detecting FLC monoclonal proteins," scientists in the United States explained.

In a recent study, T.D. Jaskowski and coauthors at the University of Utah "assessed the ability of these turbidimetric assays to detect serum monoclonal proteins involving both free and heavy-chain-bound kappa and lambda light chains compared to standard immunofixation electrophoresis."

"Sera demonstrating a restricted band of protein migration (other than a definite M spike) by serum protein electrophoresis (SPE), which may represent early monoclonal proteins, were also examined," the investigators noted. "When compared to IFE, percent agreement, sensitivity, and specificity for the kappa-FLC and lambda-FLC were 94.6, 72.9, and 99.5% and 98.5, 91.4, and 99.7%, respectively, in detecting monoclonal proteins involving free and heavy-chain-bound light chains."

"The majority of sera (73.7%) demonstrating a restricted band of protein migration on SPE demonstrated abnormal IFE patterns suggestive of multiple myeloma or monoclonal gammopathy of unknown significance, but gave normal kappa/lambda FLC ratios using the turbidimetric immunoassays," according to the study report.

"The kappa and lambda FLC assays are significantly less sensitive (72.9 to 91.4%) than IFE, but specific in detecting serum monoclonal proteins. Moreover, the kappa/lambda ratio has little value in routine screening since the majority of sera with abnormal IFE patterns had normal kappa/lambda FLC ratios," the researchers concluded.

Jaskowski and colleagues published their study in Clinical and Vaccine Immunology (Detection of kappa and lambda light chain monoclonal proteins in human serum: Automated immunoassay versus immunofixation electrophoresis. Clin Vaccine Immunol, 2006;13(2):277-280).

For more information, contact T.D. Jaskowski, University of Utah, School of Medicine, Associated Regional and University Pathologists Institute for Clinical and Experimental Pathology, 500 Chipeta Way, Salt Lake City, UT 84108, USA.

Publisher contact information for the journal Clinical and Vaccine Immunology is: American Society for Microbiology, 1752 N St. NW, Washington, DC 20036-2904, USA.

Keywords: Salt Lake City, Utah, United States, Diagnostics, Immunology, Medical Device, Multiple Myeloma, Oncology.

This article was prepared by Clinical Oncology Week editors from staff and other reports. Copyright 2006, Clinical Oncology Week via NewsRx.com.