title: Comparison of salivary and serum enzyme immunoassays for the diagnosis of Helicobacter pylori infection.
abstract: Infection with Helicobacter pylori has been established as an important risk factor for the development of peptic ulcer disease, gastritis and gastric cancer. The diagnosis of H pylori infection can be established by invasive or noninvasive techniques. Two noninvasive enzyme immunoassays (EIAs) for antibody detection - HeliSal and Pylori Stat - were compared with histology. Both assays detect immunoglobulin (Ig) G directed against purified H pylori antigen. The test populations consisted of 104 consecutive patients scheduled for upper gastrointestinal endoscopy. Of these patients, 97 (93%) had symptoms compatible with peptic ulcer disease. Saliva and serum were collected simultaneously at the time of endoscopy. Salivary EIA had a sensitivity of 66%, specificity of 67%, positive predictive value of 67% and negative predictive value of 66% compared with the serum EIA, where the results were 98%, 48%, 64% and 96%, respectively. Although the salivary EIA is an appealing noninvasive test, it was not a sensitive and specific assay. The serum EIA also lacked specificity, but was highly sensitive with a good negative predictive value. Although a negative serum EIA rules out H pylori infection, a positive result must be interpreted in the clinical context and confirmed with a more specific measure.
authors.affiliation: Departments of Medicine and.
authors.forename: J M
authors.initials: JM
authors.lastname: Embil
authors.forename: S H
authors.initials: SH
authors.lastname: Choudhri
authors.forename: G
authors.initials: G
authors.lastname: Smart
authors.forename: T
authors.initials: T
authors.lastname: Aldor
authors.forename: N M
authors.initials: NM
authors.lastname: Pettigrew
authors.forename: G R
authors.initials: GR
authors.lastname: Grahame
authors.forename: M R
authors.initials: MR
authors.lastname: Dawood
authors.forename: C N
authors.initials: CN
authors.lastname: Bernstein