Rapid salivary pepsin test: Blinded assessment of test performance in gastroesophageal reflux disease

Authors

  • Elif Saritas Yuksel MD,

    1. Division of Gastroenterology, Hepatology, and Nutrition , Vanderbilt University Medical Center, Nashville, Tennessee, U.S.A.
    2. Department of Biostatistics Vanderbilt University Medical Center, Nashville, Tennessee, U.S.A.
    3. Vanderbilt Voice Center, Vanderbilt University Medical Center, Nashville, Tennessee, U.S.A.
    4. RD Biomed Limited, Hull, United Kingdom
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  • Shih-Kuang S. Hong MD, MSCI,

    1. Division of Gastroenterology, Hepatology, and Nutrition , Vanderbilt University Medical Center, Nashville, Tennessee, U.S.A.
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  • Vicki Strugala PhD,

    1. RD Biomed Limited, Hull, United Kingdom
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  • James C. Slaughter DrPH,

    1. Department of Biostatistics Vanderbilt University Medical Center, Nashville, Tennessee, U.S.A.
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  • Marion Goutte BS,

    1. Division of Gastroenterology, Hepatology, and Nutrition , Vanderbilt University Medical Center, Nashville, Tennessee, U.S.A.
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  • C. Gaelyn Garrett MD,

    1. Vanderbilt Voice Center, Vanderbilt University Medical Center, Nashville, Tennessee, U.S.A.
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  • Peter W. Dettmar PhD,

    1. RD Biomed Limited, Hull, United Kingdom
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  • Michael F. Vaezi MD, PhD

    Corresponding author
    1. Division of Gastroenterology, Hepatology, and Nutrition , Vanderbilt University Medical Center, Nashville, Tennessee, U.S.A.
    • Division of Gastroenterology, Hepatology and Nutrition, Vanderbilt University Medical Center, 1660 TVC, 1301 22nd Ave. South, Nashville, TN 37232-5280
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  • Drs. Strugala and Dettmar are affiliated with RD Biomed Limited, which manufactures the pepsin test described in this study. Their involvement in the study was limited to providing technical support for the test. They had no influence on the study design, conduct, analysis or the final manuscript. There are no financial relationships between any of the other authors and RD Biomed Limited. The authors have no other funding, financial relationships, or conflicts of interest to disclose.

Abstract

Objective/Hypothesis:

Pepsin lateral flow device (LFD) is a rapid noninvasive test to detect salivary pepsin as a surrogate marker for gastroesophageal reflux disease (GERD). We aimed to establish the test sensitivity, specificity, positive and negative predictive values (PPV, NPV) in patients with symptomatic and objective evidence of GERD compared to healthy controls.

Study Design:

Prospective, blinded, controlled cohort study.

Methods:

A total of 230 samples were analyzed. In vitro bench testing was conducted on 52 gastric juice and 54 sterile water samples to assess test sensitivity and specificity. Saliva was collected from 58 patients with GERD and 51 controls. All patients with GERD underwent esophagogastroduodenoscopy (EGD) and wireless 48-hour pH monitoring off acid suppressive therapy. PPV and NPV were calculated based on disease definition of esophagitis and/or abnormal pH monitoring.

Results:

Receiver operating characteristics analysis of in vitro samples found assay sensitivity and a specificity of 87%. There were 6/51 (12%) control subjects and 13/58 (22%) patients with GERD who tested positive for salivary pepsin (P = .25). There was a step-wise increase in the prevalence of positive salivary pepsin: esophagitis (55%), abnormal pH monitoring (43%), GERD symptoms only (24%) (P < .001). Salivary pepsin test showed a PPV of 81% and NPV of 78% for those with objective evidence of GERD (abnormal pH and/or esophagitis).

Conclusions:

Rapid LFD for salivary pepsin has acceptable test characteristics in patients with GERD. A positive salivary pepsin test in this group may obviate the need for more expensive diagnostic testing by EGD or pH monitoring.

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