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A Quantitative Glycogen Assay to Verify Use of Self-Administered Vaginal Swabs

Anderson, Deborah J. PhD*; Politch, Joseph A. PhD*; Pudney, Jeffrey PhD*; Marquez, Cecilia I. MD*; Snead, Margaret C. PhD; Mauck, Christine MD

doi: 10.1097/OLQ.0b013e31826e880e
Original Study

Background Self-administered swabs are used to sample vaginal contents for a variety of clinical purposes including detection of sexually transmitted infections, condom breakage, and vaginal product use. The goal of this study was to determine whether a quantitative glycogen assay can be used to assess whether a swab has been exposed to the vagina to assure study compliance.

Study Design Buccal, skin, or vaginal samples were tested to determine whether a commercial quantitative glycogen assay can differentiate vaginal specimens. In addition, archived remnant de-identified vaginal swabs from clinical trials were tested. Periodic acid–Schiff stain was used to identify glycogen-positive cells as a confirmation test.

Results Glycogen concentrations in eluates of vaginal swabs from reproductive-aged women were significantly higher than those from unused swabs (mean ± SE, 964 ± 135 μg/mL vs. 14.7 ± 2.5 μg/mL, P < 0.001) and swabs exposed to buccal and finger/hand epithelia (40.3 ± 4.8 and 18.5 ± 5.4 μg/mL, P < 0.001). Glycogen concentrations were lower and more variable in vaginal swabs from older perimenopausal/menopausal women (mean ± SE, 235 ± 123, P < 0.01). Semen and sample storage longer than 1 year did not affect glycogen detection. Using a cutoff of 100 μg/mL of glycogen, 30 of 30 vaginal swabs from reproductive-aged women versus 0 of 28 control swabs were positive, for an assay sensitivity of 1 (95% confidence interval, 0.86–1) and specificity of 1 (95% confidence interval, 0.85–1). Periodic acid–Schiff stain correlated with soluble glycogen results but was less specific.

Conclusions The quantitative glycogen assay provides a simple and inexpensive method to validate the use of self-administered swabs for sampling vaginal contents in clinical studies.

The quantitative glycogen assay provides a simple and inexpensive method to validate the use of self-administered swabs for sampling vaginal contents in clinical studies.

From the *Division of Reproductive Biology, Department of Obstetrics and Gynecology, Boston University School of Medicine, Boston, MA; †Centers for Disease Control and Prevention, Atlanta, GA; and ‡CONRAD, Eastern Virginia Medical School, Arlington, VA

We would like to acknowledge the technical support from Ryan Palapaz and Caitlin Blaskewicz and valuable advice and support from Ron Frezieres, Terri Walsh, Maria Gallo, Carolyn Black, Teresa Brown, Marianne Callahan, and Jill Schwartz.

Support by the United States Agency for International Development (USAID) under USAID Cooperative Agreement GPO-A-00-08-00005-00 with CONRAD. The views expressed in this article are not necessarily those of USAID.

The authors have no conflicts of interest.

The findings and conclusions in this article are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention.

Correspondence: Deborah J. Anderson, PhD, Division of Reproductive Biology, Department of Obstetrics and Gynecology, Boston University School of Medicine, 670 Albany St, Rm 516, Boston, MA 02118. E-mail: Deborah.Anderson@BMC.org.

Received for publication April 11, 2012, and accepted August 9, 2012.

© Copyright 2012 American Sexually Transmitted Diseases Association