Clinical Chemistry
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Clinical Chemistry 51: 273-274, 2005; 10.1373/clinchem.2004.043505
This Article
Right arrow Extract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Web of Science (2)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by van der Watt, G.
Right arrow Articles by Berman, P.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by van der Watt, G.
Right arrow Articles by Berman, P.
Related Collections
Right arrow General Clinical Chemistry
Right arrow Clinical Immunology
Right arrow Cancer Diagnostics (since 2002)
Right arrow Proteomics and Protein Markers
(Clinical Chemistry. 2005;51:273-274.)
© 2005 American Association for Clinical Chemistry, Inc.

Letters to the Editor

Pseudoparaproteinemia after Iopamidol Infusion for Coronary Angiography

George van der Watta and Peter Berman

1 Division of Chemical Pathology, Groote Schuur Hospital, University of Cape Town Observatory, Cape Town, South Africa 7925

aAuthor for correspondence. Fax 027-12-4044105; e-mail georgev{at}chempath.uct.ac.za.


To the Editor:

Automated capillary zone electrophoresis (CZE) is increasingly used for separation of serum proteins in routine clinical laboratories (1). Detection of proteins is based on the absorbance of peptide bonds at 214 nm, in contrast to older, gel-based methods, which use dye binding.

A 62-year-old man with ischemic heart disease, type II diabetes, and chronic renal failure underwent coronary angiography and received 62 g (100 mL) of iopamidol (Jopamiron®; Bracco s.p.a) intraarterially during the procedure. Blood was taken ~6 h after angiography for serum protein electrophoresis (SPE). Analysis by CZE (Paragon CZE® 2000; Beckman Coulter®) showed a defined peak of "5.2 g/L" in the cathodal end of the {alpha}2-globulin region. Immunofixation on the same instrument failed to confirm this peak as an immunoglobulin, and assays for apoprotein-B100, haptoglobin, and ceruloplasmin were within reference values. Repeat CZE after 2 and 5 days showed a progressive decrease in peak size. This relatively rapid clearance suggested a nonprotein compound, which was confirmed by the absence of an abnormal band on agarose gel electrophoresis (AGE; Paragon® SPE Kit; Beckman Coulter).

To confirm the interference of iopamidol in the CZE analysis, we added iopamidol to serum aliquots to give concentrations comparable to those expected during angiography. A well-defined peak was obtained in the same zone of the {alpha}2 region in a dose-dependent fashion. Appearance on AGE was unaffected by the additions (Fig. 1 ). Iopamidol diluted in CZE buffer solution displayed an absorbance maximum of 242 nm as described previously (2). The absorbance of iopamidol at 214 nm was 75% of the peak value, accounting for its interference in the CZE analysis.



View larger version (19K):
[in this window]
[in a new window]
  		Figure 1. CZE electropherograms (top) and AGE gels (bottom) of pooled serum before (A) and after (B) addition of 6.12 g/L iopamidol.

The iopamidol peak is indicated by the arrow.

Interference of iodinated radio-opaque contrast agents in CZE analysis of serum proteins has been described, with abnormal peaks in the {alpha}2, ß, and prealbumin regions (2)(3). Radio-opaque agents are usually cleared rapidly from the serum; in this case, clearance of iopamidol was retarded by renal failure.

Clinicians may not be familiar with the potential interference of radio-opaque contrast agents in CZE. This may lead to diagnostic confusion in instances where blood for SPE by CZE is taken soon after an imaging procedure or in patients in whom renal clearance of contrast agent is defective. With the widespread use of CZE, this phenomenon may be encountered more frequently, and laboratories are urged not to discard AGE methods entirely because they have value in validating abnormal peaks on CZE.


References

  1. Bossuyt X, Schietekatte G, Bogaerts A, Blankaert N. Serum protein electrophoresis by CZE 2000 clinical capillary electrophoresis system. Clin Chem 1998;44:749-759.[Abstract/Free Full Text]
  2. Arranz-Pena ML, González-Sagrado M, Olmos-Linares AM, Fernández-Garcia N, Martin-Gil FJ. Interference of iodinated contrast media in serum capillary zone electrophoresis [Letter]. Clin Chem 2000;46:736-737.[Free Full Text]
  3. Bossuyt X, Mewis A, Blanckaert N. Interference of radio-opaque agents in clinical capillary zone electrophoresis [Technical Brief]. Clin Chem 1999;45:129-131.[Free Full Text]



The following articles in journals at HighWire Press have cited this article:


Home page
 Clin. Chem.Home page
P. Vermeersch, G. Marien, and X. Bossuyt
Pseudoparaproteinemia Related to Iomeprol Administration after Angiocardiography: Detection in the {beta} Fraction by Capillary Zone Electrophoresis
Clin. Chem., December 1, 2006; 52(12): 2312 - 2313.
[Full Text] [PDF]

This Article
Right arrow Extract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Web of Science (2)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by van der Watt, G.
Right arrow Articles by Berman, P.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by van der Watt, G.
Right arrow Articles by Berman, P.
Related Collections
Right arrow General Clinical Chemistry
Right arrow Clinical Immunology
Right arrow Cancer Diagnostics (since 2002)
Right arrow Proteomics and Protein Markers

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS