Anne-Sophie Messiaen1, Maxime M W De Sloovere1, Paul-Emile Claus1, Martine Vercammen2, Lieve Van Hoovels3, Olivier Heylen4, Johan Debrabandere1, Hilde Vanpoucke1, Dieter De Smet1.
Abstract
OBJECTIVES: Free light chain (FLC) measurement gained a lot of interest for diagnostic workup of monoclonal gammopathy.
METHODS: We evaluated the performance of turbidimetric polyclonal Freelite (The Binding Site, Birmingham, UK) assays on Cobas 6000 (Roche Diagnostics, Rotkreuz, Switzerland) and nephelometric monoclonal N Latex (Siemens Healthcare Diagnostics, Marburg, Germany) assays on BN ProSpec (Dade Behring, Deerfield, IL) vs established nephelometric Freelite assays on BN ProSpec.
RESULTS: Analytical performance was acceptable. Method comparison (n = 118) showed significant proportional FLC differences for N Latex assays. However, good correlation and clinical concordance were shown. Recovery study in the low concentration range demonstrated consistent over- and underrecovery for Freelite reagents, hampering future research on prognostic value of suppressed noninvolved FLC. Antigen excess detection was successful for κ FLC in three-fourths of cases with Freelite reagents and in all cases with N Latex reagents. However, the latter resulted in underestimated κ FLC concentrations.
CONCLUSIONS: FLC analysis requires continuous awareness of analytical limitations. Monitoring of disease response requires FLC analysis on the same platform using the same reagents. © American Society for Clinical Pathology, 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com
OBJECTIVES: Free light chain (FLC) measurement gained a lot of interest for diagnostic workup of monoclonal gammopathy.
METHODS: We evaluated the performance of turbidimetric polyclonal Freelite (The Binding Site, Birmingham, UK) assays on Cobas 6000 (Roche Diagnostics, Rotkreuz, Switzerland) and nephelometric monoclonal N Latex (Siemens Healthcare Diagnostics, Marburg, Germany) assays on BN ProSpec (Dade Behring, Deerfield, IL) vs established nephelometric Freelite assays on BN ProSpec.
RESULTS: Analytical performance was acceptable. Method comparison (n = 118) showed significant proportional FLC differences for N Latex assays. However, good correlation and clinical concordance were shown. Recovery study in the low concentration range demonstrated consistent over- and underrecovery for Freelite reagents, hampering future research on prognostic value of suppressed noninvolved FLC. Antigen excess detection was successful for κ FLC in three-fourths of cases with Freelite reagents and in all cases with N Latex reagents. However, the latter resulted in underestimated κ FLC concentrations.
CONCLUSIONS: FLC analysis requires continuous awareness of analytical limitations. Monitoring of disease response requires FLC analysis on the same platform using the same reagents. © American Society for Clinical Pathology, 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com
Entities:
Keywords:
Free light chains; Monoclonal; Monoclonal gammopathy; Myeloma; Nephelometry; Polyclonal; Turbidimetry
Mesh：
Substances：
Year: 2017
PMID： 28575180 DOI： 10.1093/ajcp/aqx037
Source DB: PubMed Journal: Am J Clin Pathol ISSN： 0002-9173 Impact factor: 2.493