Evaluation of a commercial latex test for serological diagnosis ofHelicobacter pylori infection in treated and untreated patients

The value of a commercially available latex test (Pyloriset) for the diagnosis ofHelicobacter pylori infection by demonstration of specific antibodies was compared with that of direct diagnostic methods such as culture, biopsy-urease test and microscopy of fuchsin-stained smears. The sera were from 136 patients who prior to this study either had or had not been treated forHelicobacter pylori-infection simultaneously with amoxicillin (3 × 750 mg/day) and metronidazole (3 × 500 mg/day) for 12 days. On average, the sensitivity of the test was 90 %. The specificity with sera from untreated patients was 75.9 %; with sera from treated patients specificity was 22.2 %, 28 % and 20 % 1, 3 and 6 months respectively after start of treatment. Only as late as one year after the onset of chemotherapy did the specificity return to 67 %. Because of its low specificity this test does not offer any advantage over other tests in the detection ofHelicobacter pylori-infection or in monitoring the chemotherapeutic success.