The reliability of ELISA in predicting H. pylori infection in dyspeptic populations under age 45

Dyspepsia is a common problem worldwide. Many dyspeptic patients have no alarm symptoms and are diagnosed by family doctors. Non-invasive testing of H. pylori is recommended in patients up to the age of 55. Testing of asymptomatic high risk groups is now being considered in many countries. The aim of the study was to compare the accuracy of serology tests (ELISA, HelicoTest) against the benchmark UBT (urea breath test) in the detection of H. pylori infection in young populations.

The study was conducted on 238 patients under age 45 (159 with undiagnosed dyspepsia and 79 controls). The gold standard of diagnosis of H. pylori infection was based on a positive UBT. UBT, serological ELISA and HelicoTest were performed on each of the patients.

By UBT 50.9% and by ELISA 49.7% of dyspeptic patients were infected with H. pylori, while in the control group 38% and 39.2% were infected, respectively. HelicoTest showed the highest positive results in both groups (55.3% study group, 44.3% control). The average level of IgG antibodies from ELISA testing among patients with a positive UBT H. pylori result was 3.16 U/ml. Patients with negative UBT results showed an average IgG level of 0.53 U/ml.

There was a correlation of increasing antibody level on ELISA and probability of testing positive on UBT. The majority of patients had moderate dyspeptic symptoms. The ELISA is an easy, cheap and effective method for diagnosing H. pylori infection in the primary care setting.