Objectives: To determine prospectively the effect of aspirin, nonsteroidal anti-inflammatory drugs, H2-receptor antagonists, proton pump inhibitors, alcohol intake, race, age, history of Helicobacter pylori eradication attempts, and gastric biopsy location on CLOtest performance.
Methods: Biopsy specimens were obtained from the antrum, greater curve, and proximal stomach. One biopsy specimen from each site (except for the proximal stomach) was used for the CLOtest and two or more specimens were used for histopathology. Giemsa staining was used for the definitive determination of H. pylori status.
Results: One hundred seventeen patients were included in the study, and 50 of these were infected with H. pylori. The sensitivity and specificity of an antral CLOtest, based on the results of Giemsa-stained sections from the antrum alone, were 72.7 and 98.6%, respectively, whereas they were 66.0 and 100% when based on the results of Giemsa-stained sections from all three gastric biopsy sites. The sensitivity and specificity of a body CLOtest, based on the results of Giemsa-stained sections from the body alone, were 80.5% and 93.4%, whereas they were 76.0% and 100% when based on the results of Giemsa-stained sections from all three gastric biopsy sites. Combining CLOtest results from the antrum and body increased CLOtest sensitivity to 82.0%. Univariate analysis revealed only one factor significantly associated with CLOtest concordance: absence of alcohol consumption (p < 0.02). Stepwise logistic regression demonstrated that absence of alcohol use again was independently associated with the concordance between overall CLOtest and all Giemsa-stained biopsy specimen results (p < 0.03) as well as between body CLOtest and body Giemsa-stained biopsy specimen results (p < 0.03). Additional independent and significant associations were noted between antral CLOtest-antral Giemsa-stained biopsy specimen results and no history of H. pylori eradication attempts (p = 0.04) and between body CLOtest-body Giemsa-stained biopsy specimen results and race (African-American) (p < 0.03).
Conclusions: Obtaining a gastric biopsy specimen from the antrum as well as from the body increased CLOtest detection of H. pylori. CLOtest performance was shown to be affected by several demographic and clinical factors.