A significant increase in the pepsinogen I/II ratio is a reliable biomarker for successful Helicobacter pylori eradication

BACKGROUND: Helicobacter pylori (H. pylori) eradication is usually assessed using the (13)C-urea breath test (UBT), anti-H. pylori antibody and the H. pylori stool antigen test. However, a few reports have used pepsinogen (PG), in particular, the percentage change in the PG I/II ratio. Here, we evaluated the usefulness of the percentage changes in serum PG I/II ratios for determining the success of eradication therapy for H. pylori. MATERIALS AND METHODS: In total, 650 patients received eradication therapy from October 2008 to March 2013 in our Cancer Institute Hospital. We evaluated the relationship between H. pylori eradication and percentage changes in serum PG I/II ratios before and 3 months after treatment with CLEIA(®) (FUJIREBIO Inc, Tokyo, Japan). The gold standard of H. pylori eradication was defined as negative by the UBT performed 3 months after completion of eradication treatment. Cut-off values for percentage changes in serum PG I/II ratios were set as +40, +25 and +10% when the serum PG I/II ratio before treatment was below 3.0, above 3.0 but below 5.0 and 5.0 or above, respectively. RESULTS: Serum PG I and PG II levels were measured in 562 patients with H. pylori infection before and after eradication therapy. Eradication of H. pylori was achieved in 433 patients studied (77.0%). The ratios of first, second, third-line and penicillin allergy eradication treatment were 73.8% (317/429), 88.3% (99/112), 75% (12/16) and 100% (5/5), respectively. An increasing percentage in the serum levels of the PG I/II ratios after treatment compared with the values before treatment clearly distinguished success from failure of eradication (108.2±57.2 vs. 6.8±30.7, p<0.05). Using the above cut-off values, the sensitivity, specificity and validity for determination of H. pylori were 93.1, 93.8 and 93.2%, respectively. CONCLUSION: In conclusion, the percentage changes in serum PG I/II ratios are useful as evaluation criteria for assessing the success of eradication therapy for H. pylori.