Su1132 Helicobacter pylori First-Line and Rescue Treatments in the Presence of Penicillin Allergy

Background and Aim: A combined panel of serum anti-Helicobacter pylori antibodies and serum pepsinogen (PG) levels (referred to as the "ABC system") is effective in evaluating an individual's risk of gastric cancer (GC).In the ABC system, patients who are H. pyloriseronegative and have high PG levels are classified as "Group A"; these patients are thought to have a very low risk of developing GC.However, GC cases are occasionally observed in this group, and the most common cause of this discrepancy is the inclusion of subjects with current or past H. pylori infection in Group A (the "pseudo A" group).In our study, we aimed to clarify the difference in the clinicopathological features of the "true A" and "pseudo A" groups.Subjects and Methods: A total of 1,207 patients who were evaluated for serum anti-H.pylori antibodies and serum PG levels were enrolled in our study.We classified them to according to the ABC system, and 200 patients with gastric biopsy specimens were included in Group A for analysis (103 men; mean age, 54.8 years).We used the histological assessments to group patients into the true A group (no histological gastritis) and the pseudo A group (histologically positive gastritis).Histological gastritis of the antrum and corpus was diagnosed based on atrophy, chronic inflammation, and intestinal metaplasia according to the updated Sydney system.In addition, we evaluated the two groups' serum gastrin levels.Patients with a history of previous H. pylori eradication therapy were excluded.All results are expressed as mean ± standard deviation.Results: Among the Group A patients, 19% (38 cases) of patients were pseudo A and 81% (162 cases) of patients were true A. Based on the histological evaluation, most pseudo A patients had moderate atrophy, mononuclear cells infiltration, and intestinal metaplasia.Based on the endoscopic diagnosis, 15 of 38 patients (39.5%) in the pseudo A group had GC, whereas only 1 patient (0.6%) had GC in the true A group.The pseudo A group had a significantly lower mean PG I/II ratio (5.32 ± 2.05 vs. 6.26 ± 1.85, P < 0.01) and significantly higher gastrin level (175.0 ± 155 pg/ml vs. 120.2± 111 pg/ml, P < 0.01) compared to the true A group.Conclusions: Our results indicate that the pseudo A patients in Group A were at risk of developing GC, and a combination of serum markers (pepsinogen and gastrin) and histological assessment was useful for detecting cases of GC within the pseudo A group.