Obstetrics & Gynecology Email Alerts
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Obstetrics & Gynecology 2005;105:449-450
© 2005 by The American College of Obstetricians and Gynecologists
This Article
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 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
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Sheffield, J. S.
Right arrow Articles by Wendel, G. D.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Sheffield, J. S.
Right arrow Articles by Wendel, G. D., Jr

Letter to the Editor

False Positive Results for the AUSZYME Monoclonal Test

Jeanne S. Sheffield, MD, Vanessa R. Laibl, MD, Scott W. Roberts, MD, MS and George D. Wendel, Jr, MD

Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, Texas

To the Editor:

On November 18, 2004, the National Center for Infectious Diseases posted a notice warning physicians that BD Diagnostics and Abbott Diagnostics were investigating an increase in false-positive hepatitis B surface antigen (HbsAg) results for the AUSZYME Monoclonal test when using BD Vacutainer SST Plus tubes. The BD Vacutainer serum separator tubes may have an interfering substance that affects a number of analytes, including follicle-stimulating hormone, thyroid hormones, cortisol, folate, and B12, depending on the testing instrument used. Because BD is a major supplier of serum separator tubes to hospitals and clinics, clinicians need to be aware of their specific laboratory practices.

This issue has broad implications for practicing obstetricians screening pregnant women for hepatitis B virus carrier state by HBsAg testing. We noticed an increase in false-positive HBsAg testing at our institution, starting in August 2004 (Fig. 1). All pregnant women are screened at their first prenatal visit. Over a 3-month time period, we identified 24 women testing positive for HBsAg. Nineteen of these women were negative on confirmatory testing (false-positive HBsAg).



View larger version (15K):
[in this window]
[in a new window]
  		Fig. 1. False Positive HBsAg Results by month in 2004.

Sheffield. Letter to the Editor. Obstet Gynecol 2005.

 

BD is now adjusting the Vacutainer SST collection tubes and the Microtainer tubes and is completing clinical validation of the adjusted product to assure clinical performance in specific instrument/assay combinations.4 Clinicians should ensure that they are using the adjusted collection tubes or switch to new blood collection tubes. We have begun using new collection tubes, and our false-positive HBsAg rate has returned to baseline.

Practicing clinicians need to be aware of their laboratory practices. Reactive HBsAg tests should be repeated in duplicate. If either of the repeat tests is positive, the sample should be tested using an HBsAg neutralizing confirmatory test. Only then can an HBsAg test be considered a true positive test.

doi:10.1097/01.AOG.0000154475.56997.a4

REFERENCES

1. Gotstein MG, Aide PM, Coleman PF, Sanborn MR. Rate of hepatitis B virus infection in pregnant women determined by a monoclonal hepatitis B surface antigen immunoassay. J Clin Microbiol 2002;40:3493–6.[Abstract/Free Full Text]

2. BD Diagnostics technical bulletin. September 17, 2004. Available at: http://www.bd.com/vacutainer/pdfs/techbulletins/Abbott_Diagnostics_17september2004_VS7310.pdf. Retrieved December 17, 2004.

3. National Center for Infectious Diseases. Viral hepatitis. Available at: http://www.cdc.gov/ncidod/diseases/hepatitis/new.htm#top. Retrieved December 17, 2004.

4. Available at: BD Diagnostics technical bulletin. November 10, 2004. Available at: http://www.bd.com/vacutainer/pdfs/techbulletins/Assay_Interference_Microtainer_10november2004_VS7326.pdf. Retrieved December 17, 2004.




This article has been cited by other articles:


Home page
 Clin. Chem.Home page
R. A.R. Bowen, Y. Chan, M. E. Ruddel, G. L. Hortin, G. Csako, S. J. Demosky Jr, and A. T. Remaley
Immunoassay Interference by a Commonly Used Blood Collection Tube Additive, the Organosilicone Surfactant Silwet L-720
Clin. Chem., October 1, 2005; 51(10): 1874 - 1882.
[Abstract] [Full Text] [PDF]

This Article
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 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
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Sheffield, J. S.
Right arrow Articles by Wendel, G. D.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Sheffield, J. S.
Right arrow Articles by Wendel, G. D., Jr

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS