Conflict of interest: SKK was involved in design of concept, data collection, analysis, and writing the paper, AD, MQL, SRH, SRZ, FKB, NL, RAK, SVR, and MAG were involved in writing the manuscript. AD, Honoraria from Binding site for lecture. RAK, Honoraria from Binding site for lecture. SKK, MQL, SRH, SRZ, FKB, NL, SVR, and MAG none relevant to this manuscript.
Changes in serum-free light chain rather than intact monoclonal immunoglobulin levels predicts outcome following therapy in primary amyloidosis†
Version of Record online: 15 FEB 2011
Copyright © 2011 Wiley-Liss, Inc.
American Journal of Hematology
Volume 86, Issue 3, pages 251–255, March 2011
How to Cite
Kumar, S. K., Dispenzieri, A., Lacy, M. Q., Hayman, S. R., Buadi, F. K., Zeldenrust, S. R., Tan, T., Sinha, S., Leung, N., Kyle, R. A., Rajkumar, S. V. and Gertz, M. A. (2011), Changes in serum-free light chain rather than intact monoclonal immunoglobulin levels predicts outcome following therapy in primary amyloidosis. Am. J. Hematol., 86: 251–255. doi: 10.1002/ajh.21948
- Issue online: 23 FEB 2011
- Version of Record online: 15 FEB 2011
- Accepted manuscript online: 2 DEC 2010 10:13AM EST
- Manuscript Accepted: 23 NOV 2010
- Manuscript Received: 17 NOV 2010
- Hematologic Malignancies Program, Paul Calabresi K12 grant
- National Cancer Institute. Grant Numbers: CA62242, CA93842, CA10080
- National Institutes of Health
- Department of Health and Human Services
Current response criteria for light-chain amyloidosis (AL) relegate FLC response to a subsidiary status relative to serum M-protein response. Given that light chains form the substrate for amyloid fibril formation, we hypothesized that changes in FLC might better predict outcome compared to changes in intact immunoglobulin levels. Two patient cohorts were studied, 347 patients who underwent an autologous stem-cell transplant (SCT) and 96 patients treated with melphalan/dexamethasone. We identified the lowest value following therapy for intact serum M-protein and the difference between involved and uninvolved FLC (FLC-diff). We first examined the relative contribution of M-protein and FLC-diff on the overall survival (OS), and found that FLC reduction, rather than M-protein reduction, significantly impacted OS. The median OS was not reached among those with a 50% decrease in FLC-diff compared to 20 months for the remainder. On regression analysis, a 90% reduction in FLC-diff following SCT best predicted being alive at 3 or 5 years. The median OS among those with a 90% decrease was not reached compared to 37.4 months for the rest P < 0.001. The current study supports the notion that FLC response is a more useful measure of hematological response than M-protein response. It also highlights the importance of achieving at least a 90% reduction in the FLC-diff to improve the outcome of patients with light-chain AL. Am. J. Hematol. 2011. © 2011 Wiley-Liss, Inc.