Noninvasive diagnosis of Helicobacter pylori infection in older subjects: Comparison of the C-13-urea breath test with serology

Background. The potential influence of cognitive status, physical activitie s, comorbidity and cotreatments on the feasibility and diagnostic accuracy of two noninvasive diagnostic tests for Helicobacter pylori (Hp) infection, i.e., the C-13-urea breath test(C-13-UBT) and serology (immunoglobulin G [ Igc] anti-Hp antibodies), in older subjects is not known. Method. The study involved 100 consecutive symptomatic elderly subjects (me an age, 78.3 years; range, 65-96 years), who had undergone an upper gastroi ntestinal endoscopy. Patients were considered Hp positive if at least two o f the three invasive methods, i.e. histology, culture, and/or the rapid ure ase test were positive for Hp infection. Patients were considered Hp negati ve if all three invasive methods were negative. The C-13-UBT was performed according to the European standard method and the assaying of IgG anti-Hp a ntibodies by enzyme-linked immunosorbent assay. Cognitive status and functi onal activities were determined by the Mini-Mental State Examination (MMSE) , the activities of daily living (ADLs) and instrumental ADLs (IADLs). Results. According to invasive methods, 49 patients were Hp positive and 47 were Hp negative (4 subjects were excluded from the study). Hp-positive pa tients demonstrated a significantly higher prevalence of peptic ulcers (p=. 02) and activity of chronic gastritis (p<.0001) than tip-negative subjects. The C-13-UBT demonstrated a sensitivity of 100%, a specificity of 95.7%, a nd a diagnostic accuracy of 97.9%. Serology had significantly lower sensiti vity (74.4%), specificity (59%), and diagnostic accuracy (67%, p<.001) than the C-13-UBT. The feasibility and the diagnostic accuracy of the C-13-UBT were not altered by the cognitive status (MMSE) and functional activities ( ADL, IADL) of the patients, their drug consumption, or the prevalence of co ncomitant diseases. Conclusions, In older subjects, the C-13-UBT had a significantly higher dia gnostic accuracy than serology without influence of cognitive function, dis ability, comorbidity and cotreatments. This method may be considered an exc ellent, clinically useful, noninvasive test for the diagnosis of Hp infecti on in older subjects.