Diagnosis and monitoring for light chain only and oligosecretory myeloma using serum free light chain tests. (1st June 2017)

• Record Type: Journal Article
• Authors: Heaney, Jennifer L. J.; Campbell, John P.; Griffin, Anne E.; Birtwistle, Jane; Shemar, Meena; Child, J Anthony; Gregory, Walter M.; Cairns, David A.; Morgan, Gareth; Jackson, Graham; Drayson, Mark T.
• Is Part Of: British journal of haematology. Volume 178:Number 2(2017)
• Page Start: 220
• Page End: 230
• Publication Date: 2017-06-01
• Subjects: free light chains -- multiple myeloma -- serum -- non‐secretory -- quantitation -- survival; Hematology -- Periodicals; Blood -- Diseases -- Periodicals; 616.15
• DOI: 10.1111/bjh.14753
• Languages: English
• ISSNs: 0007-1048

Abstract

Summary: This study aims to guide the integration of serum free light chain (sFLC) tests into clinical practice, including a new rapid test (Seralite ® ). Blood and urine analysis from 5573 newly diagnosed myeloma patients identified 576 light chain only (LCO) and 60 non‐secretory (NS) cases. Serum was tested by Freelite ® and Seralite ® at diagnosis, maximum response and relapse. 20% of LCO patients had urine FLC levels below that recommended for measuring response but >97% of these had adequate sFLC levels (oligosecretory). The recommended Freelite ® sFLC ≥100 mg/l for measuring response was confirmed and the equivalent Seralite ® FLC difference (dFLC) >20 mg/l identified. By both methods, ≥38% of NS patients had measurable disease (oligosecretory). Higher sFLC levels were observed on Freelite ® at all time points. However, good clinical concordance was observed at diagnosis and in response to therapy. Achieving at least a very good partial response according to either sFLC method was associated with better patient survival. Relapse was identified using a Freelite ® sFLC increase >200 mg/l and found 100% concordance with a corresponding Seralite ® dFLC increase >30 mg/l. Both Freelite ® and Seralite ® sensitively diagnose and monitor LCO/oligosecretory myeloma. Rapid testing by Seralite ® could fast‐track FLC screening and monitoring. Response by sFLC assessment was prognostic for survival and demonstrates the clinical value of routine sFLC testing.