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Clinical Chemistry and Laboratory Medicine (CCLM)

Published in Association with the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM)

Editor-in-Chief: Plebani, Mario

Ed. by Gillery, Philippe / Lackner, Karl J. / Lippi, Giuseppe / Melichar, Bohuslav / Schlattmann, Peter / Tate, Jillian R. / Tsongalis, Gregory J.

13 Issues per year

IMPACT FACTOR 2013: 2.955
Rank 5 out of 29 in category Medical Laboratory Technology in the 2013 Thomson Reuters Journal Citation Report/Science Edition

SCImago Journal Rank (SJR): 0.860
Source Normalized Impact per Paper (SNIP): 1.046



False Increase in Serum C-Reactive Protein Caused by Monoclonal IgM-λ: a Case Report

Anna Yu / Ulla Pira

Citation Information: Clinical Chemistry and Laboratory Medicine. Volume 39, Issue 10, Pages 983–987, ISSN (Print) 1434-6621, DOI: 10.1515/CCLM.2001.160, June 2005

Publication History

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Interference caused by human anti-animal antibodies has been described in many laboratory assays. Usually the antigen giving rise to these antibodies is not known. When present in sufficiently high titer, these antibodies may have a significant effect on laboratory assays, causing falsely increased or decreased values, to the detriment of patient care and laboratory diagnosis. We report a case of an 86-year old man who had greatly increased C-reactive protein (CRP) levels in serum (>500 mg/l), suggestive of an unusually strong inflammatory response such as seen in septicemia. Because this diagnosis was not consistent with his symptoms, CRP measurements were repeated using alternative methods, none of which gave CRP results higher than 12 mg/l. Protein electrophoresis followed by immunofixation showed a monoclonal IgM-λ paraprotein (7 g/l), which bound the goat anti-CRP antibodies used in the first CRP assay. Precipitation of the IgM-λ paraprotein eliminated the interference. Subsequent bone marrow tests did not reveal any blood malignancy, and the monoclonal IgM component was attributed to monoclonal gammopathy of unknown significance. In conclusion, an IgM-λ paraprotein was shown to cause falsely elevated CRP values in an automated immunometric assay using goat anti-CRP antibodies.

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