Treatment of Helicobacter pylori in children ports on the comparison of eradication rate of between BAM and OAC regimen in Korean children. For effective treatment regimens, the treatment should ach- ieve an eradication rate of over 80% on a rigorous intention to treat basis and over 90% on a per protocol basis (11-13). This result may imply per protocol analysis because we en- rolled retrospectively the only children who completed the prescribed regimen and followed up; therefore there needs a better regimen to eradicate H. pylori in children more effec- tively. Result of susceptibility testing yields best treatment out- come, however susceptibility testing is generally unavailable. Therefore, study of antibiotic susceptibility in Korean chil- dren infected with H. pylori will be necessary. Clarithromycin and metronidazole are important key anti- biotics in the treatment of H. pylori infection especially in children, so increasing resistance to both antibiotics has be- come a major problem in eradication, including in children (6-8, 14, 15). In Korean children, the resistance rate of H. pylori to clarithromycin was 19% in 2000 (16) and that in our un- published personal data in 2005 was 33% (unpublished per- sonal data in 9 children). These results suggest that the rate of clarithromycin is increasing in Korean children. Those in Korean adult also showed increasing rate of resistance from 7.1% in 1999 to 13.8% in 2003 (17). For example, of chil- dren infected with H. pylori, the rate of resistance to clarithro- mycin has been reported to range from 12.4% to 23.5% in Europe, from 10.6% to 25% in North America, and from 5.4% to 17% in East Asia (8). The essential risk factor for clarithromycin resistance is pre- vious consumption of macrolides (18-20). Macrolides, which include clarithromycin, azithromycin, and erythromycin, have been used in Korea since the early 1990s to treat children with respiratory tract infections, enterocolitis, otitis media, and chronic sinusitis. During macrolides treatment, H. pylori col- onizing the stomach of a child may become resistant to clar- ithromycin, leading to high rates of primary clarithromycin resistance (21). Metronidazole has been used as a primary antimicrobial agent to treat H. pylori infection because it is actively secret- ed in the saliva and gastric juice, becoming highly concen- trated in the stomach. In Europe and the U.S.A., the preva- lence of H. pylori resistance to metronidazole has been found to vary from 20% to 40% (22-24), and its prevalence is much higher in developing countries (50-80%) (25). In contrast, H. pylori resistance to metronidazole is quite low in Japan (9-12%) (26). In Korean adult, H. pylori resistance to metron- idazole has increased from 52.9% in 1987 to 66.2% in 2003 (17). In Korean children in our unpublished personal data in 2005 was 44% (unpublished personal data in 9 children). Recently, doubly resistant strains have been reported world- wide, but their prevalence is still low in Europe (0.8-9.1%) and Asia (2-3%) (27, 28). In our study, 6 children failed treat- ment with both the OAC and BAM regimens, suggesting 1039 that they may harbor multi-drug resistant strains of H. pylori and in our unpublished data 33% children showed resistance to both clarithromycin and metronidazole. We changed OAC as first-line treatment since 2001, be- cause NASPGHN (North American Society for Pediatric Gastroenterology, Hepatology and Nutrition) (5) recommend- ed bismuth compound as second-line treatment because of the availability and clinician’s reluctance to use bismuth com- pound, however BAM regimen showed superior eradication rate to OAC regimen. In some studies, poor compliance has been a major risk factor for failure to eradicate H. pylori infection (29). In our study, the compliance was not investigated, so we could not estimate the compliance issue. Our study had several limitations. Firstly, we could not evaluate compliance and eradication rate to intention to treat and per protocol since it was not a randomized controlled study, although we found no demographic differences between children treated with the two triple regimens. Secondly we do not have antibiotic susceptibility testing data, which might have given more detailed information. In conclusion, we have compared the efficacy of a metron- idazole-based regimen and a clarithromycin-based regimen in a large population of children infected with H. pylori. Our study showed that the triple therapy with BAM was more effective for the first-line eradication of H. pylori infection in Korean children, but has no statistical difference with OAC regimen. REFERENCES 1. 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