Research

Diagnosing vaginal infections through measurement of biogenic amines by ion mobility spectrometry
Jack D. Sobel a,*, Zeev Karpas b,c, Avraham Lorber c
a. Harper University Hospital, Division of Infectious Diseases, Wayne State University School of Medicine, MI, USA
b. 3QBD Ltd., 8 Haplada Street, Arad 89106, Israel
c. Chemistry Department, Nuclear Research Center, Negev, Beer-Sheva 84190, Israel

Abstract
Objective: To compare diagnosis of bacterial vaginosis according to the Amsel criteria with measurement by ion mobility spectrometry (IMS) of the biogenic amines that are present in vaginal discharge fluid. Study design: Duplicate samples of vaginal fluid were collected from 115 unselected and consecutive patients in a vaginitis clinic in Detroit. All samples were evaluated using Amsel criteria and the results were compared with the diagnosis based on the IMS results. Results: The incidence rate of vaginal infections was assessed on the basis of both tests and the frequency of BV was found to be 17.4%. The sensitivity and specificity for bacterial vaginosis diagnosis using IMS determination were 95.5% and 98.9%, respectively, with an accuracy of 94.4%. Conclusions: The results show that IMS may be used to rapidly diagnose this common vaginal infection with high accuracy.

©2012 Published by Elsevier Ireland Ltd.





Novel application for ion mobility spectrometry: diagnosing vaginal infections through measurement of biogenic amines

Zeev Karpas a,∗, Walter Chaimb, Rachel Gdalevsky a, Boris Tilman a, Avi Lorber a
a.  Q-Scent Ltd., Advanced Technologies Center, Rotem Industrial Park, Arava 86800, Israel
b. Soroka Medical Center, Beer-Sheva, Israel


Abstract
A method for diagnosis of bacterial vaginosis (BV) and other vaginal infections, based on measurement of biogenic amines present in a sample of vaginal fluid by ion mobility spectrometry (IMS) was developed. Sample introduction is through a two step procedure: addition of alkaline solution to release the volatile amines followed by heating and acid addition for emanation of the semi-volatile amines. Addition of n-nonylamine vapors to the carrier gas stream helps control the ionization processes and enhances the selective response to amines, even in the complex environment of biological matrices. A software package was developed for acquisition, storage and processing of the mobility spectra and for providing a diagnosis based on a table of rules. We report the results from testing of 210 samples of vaginal discharge fluid that were diagnosed by a gynecologist according to the widely used reference method (Amsel test) and by the new IMS method. The new method is rapid (less than 2min per sample), has a high sensitivity (few False Negatives) and specificity (few False Positives) with an accuracy of >95% for BV. The use of this method can reduce the incidence of misdiagnosis, particularly when trichomoniasis is confused with bacterial vaginosis.

© 2002 Elsevier Science B.V. All rights reserved.


 

New technology for diagnosis of bacterial vaginosis
Walter Chaima,*, Zeev Karpasb, Avi Lorberb

a. Department of Obstetrics & Gynecology, Faculty of Health Sciences, Soroka University Medical Center, Ben Gurion University of the Negev, P.O. Box 151, Beer Sheva 84101, Israel
b. Q-Scent Ltd., Rotem Industrial Park, Arava 86800, Israel



Abstract
Objective: To replace clinical diagnosis of bacterial vaginosis (BV) with a new and rapid analytical method based on ion mobility spectrometry (IMS). IMS is an instrumental technique for identifying compounds and determining their concentrations, based on measurement of the velocity of ions drifting through air at atmospheric pressure under the influence of an electric field. The technique is particularly sensitive to amines taking less than 2 min. Study design: Clinical examination of 174 samples determined 22 BV-positive and 152 BV-negative samples. IMS analyzed and recorded biogenic amine emanation mobility spectra of the 174 samples of vaginal discharge from duplicate swabs. Results: IMS confirmed 21 (true positive BV) samples with 1 false negative (21/22, sensitivity ј 95:5%). Out of 152 samples, 150 were confirmed true BV-negative with 2 false positive samples (specificity ј 98:7%), PPV: 91.3%, NPV: 100%. Conclusions: The diagnostic procedure shows high accuracy and is technically simple and rapid. The trimethylamine level becomes an index of severity of the infection.

© 2003 Elsevier Ireland Ltd. All rights reserved.
 

 


Diagnosis of vaginal infection ion mobility spectrometry
Zeev Karpas1, Walter Chaim2, Rachel Gdalevsky1, Boris Tilman1and Avi Lorber1

a. Q-Scent Ltd., Advanced Technologies
Center, Rotem Industrial Park, Arava 86800.
b. Soroka Medical Center, Beer-Sheva, Israel.

Abstract
Amino-acids are the building blocks of all living matter and are thus present in any material of biological origin. In organisms and plants biogenic amines are formed by degradation of amino-acids through microbial and enzymatic processes. Among those compounds are amines, diamines and polyamines, such as trimethylamine (TMA), putrescine, cadaverine, histamine, spermidine, etc. The volatile and semi-volatile biogenic amines that emanate from samples of vaginal discharge were measured by ion mobility spectrometry (IMS). The samples were collected on a cotton swab by a gynecologist during a standard examination or after the patient had specific complaints of vaginal pruritus. A correlation was found between vaginal infections, like bacterial vaginosis (BV), candidiasis (yeast infection) and trichomoniasis, and the types and quantities of biogenic amines in these samples. A dedicated software package carries out the signal acquisition and processing automatically and provides the gynecologist with a recommended diagnosis. Q-Scent has developed a rapid, accurate and inexpensive method for diagnosing common vaginal infections from the mobility spectrum. To date the method has been applied to diagnose several hundred samples in Israel and the USA.

IJIMS 5(2002)3, 49-54, p.50

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