medical Immunology lab technician ziv medical center Safed North Israel, HaZafon, Israel
Abstract:
Background: Multiple myeloma (MM) is the second most common hematological malignancy after non-Hodgkin lymphoma. Diagnosis of monoclonal gammopathies (MGs) is determined by demonstration of a monoclonal immunoglobulin molecule or chain in serum and/or urine. Since 2001, the serum free light chain (FLC) test has been available and its clinical utility proven, but guidelines have not recommended it as a replacement for electrophoresis. There is no evidence about concordance between paraprotein levels and FLC measurements Methodology: serum FLCκ and FLCλ (sFLC) concentrations are routinely measured at the Ziv Medical center biochemistry labs by Freelite® (The Binding Site Group Ltd, UK) on a Beckman Coulter AU680 and Binding site SPA-PLUS. Paraprotein levels are measured by Sebia Capillarys 2 Instrument from serum electrophoresis and immunofixation. Correlation between paraprotein value and light chain in serum to examine the relationship between FLC and paraprotein levels in order to determinate significance of this ratio for patient treatment and for obtaining more meaningful information from these test results. Resuts: The preliminary results show us a correlation (R2=91, R2=85) between paraprotein and FLC ratio and between paraprotein and Kappa light chain in IgG kappa gammopathy. In case of IgA gammopathies these correlations are less significant.
Discussion and
Conclusion: We found good agreement between methods for MM response assessment, but the FLC test analysis was more sensitive than the paraprotein evaluation during follow-up in monoclonal gammopathy patients. To our Knowledge, this is the first report comparing FLC and paraprotein levels and ratio for response assignment based on the International Myeloma Working group guidelines. We will report on patients that have different patterns of paraprotein secretion in different types of heavy and light chains MM. Assessment the concordance or discordance between FLCκ, FLCλ or FLCκ/FLCλ and Paraprotein levels can be useful tool in monoclonal gammopathies diagnosis, follow-up and treatment.
