Helicobacter pylori colonization in the first 3 years of life in Japanese children.

BACKGROUND: Acquisition of Helicobacter pylori infection occurs in early childhood, but the exact time of the acquisition and dynamics of infection are not clear. The aim of this study was to estimate the time of acquisition of H. pylori colonization in infants. SUBJECTS AND METHODS: This prospective follow-up study included 237 infants born in Wakayama Rosai Hospital from February, 2001 to April, 2002. Stool samples were collected at indicated ages, and H. pylori antigens were determined by a stool antigen test, HpSA. RESULTS: One-hundred and eight infants among initially enrolled 237 children have been followed up until 24 months. Among these, 16 infants turned to be HpSA positive within 12 months, but only four remained positive by the consecutive tests with optical density values of more than 0.7. They were assumed persistent positives. The rest 12 infants reverted to be negative by the consecutive tests and were assumed transient or false-positives. The optical density values of HpSA in the transient cases were exclusively less than 0.35. CONCLUSIONS: The consecutive follow up of HpSA, but not the one-point test, might be useful to diagnose persistent colonization of H. pylori in young infants, and some infants seemed to acquire H. pylori infection in the first year of life. These results should be taken into account for prevention and treatment strategies for H. pylori infection in infants.

Bovine lactoferrin is effective to suppress Helicobacter pylori colonization in the human stomach: a randomized, double-blind, placebo-controlled study.

Bovine lactoferrin (bLF) has antibacterial activity against Helicobacter pylori in vitro and is effective to suppress bacterial colonization in mice. The aim of our study was to evaluate the efficacy of orally administered bLF on H. pylori colonization in humans by a randomized, double-blind, placebo-controlled study. Fifty-nine healthy subjects positive for H. pylori infection were recruited. Subjects were randomized into two groups. The bLF group received bLF tablets at a dosage of 200 mg b.i.d. for a period of 12 weeks, and the control group received placebo tablets without bLF. The (13)C-urea breath test (UBT) was performed before, during, and at the end of administration, and again 4 weeks after administration. Positive response was defined as more than 50% decrease of the UBT value at the end of administration. Positive response was observed in 10 of 31 bLF-treated subjects (32.3%) and 1 of 28 control subjects (3.6%), indicating that the rate of positive response in the bLF group was significantly higher than that in the control group (bLF vs. control, P < 0.01). These results suggested that bLF administration is effective to suppress H. pylori colonization.

A strain-specific antigen in Japanese Helicobacter pylori recognized in sera of Japanese children.

An enzyme immuno assay (EIA) test based on Japanese strain-derived high-molecular-weight cell-associated proteins (JHM-CAP) was evaluated by comparing with a previously developed EIA test based on a U.S. strain-derived high-molecular-weight cell-associated proteins (HM-CAP). Serum samples of 131 Japanese asymptomatic children (mean age, 5.5 years; range, 0 to 21 years) were tested that include 43 positive and 88 negative children as judged by Helicobacter pylori stool antigen test (HpSA test). Both tests showed comparable and reliable specificities, but the sensitivity of JHM-CAP EIA, at 93.0%, was much higher than that of HM-CAP EIA, at 67.4%. More false-negative results of HM-CAP were obtained in children under 10 years of age. Immunoblot analysis revealed that the JHM-CAP but not the HM-CAP preparation had a 100-kDa antigen recognized by JHM-CAP positive sera. It was concluded that JHM-CAP EIA is highly accurate for the serodiagnosis of H. pylori infection in Japanese young children and that the high sensitivity of JHM-CAP EIA in contrast to HM-CAP EIA is due to the presence of a 100-kDa antigen in Japanese strains that may be recognized by the host immune system at an early stage of infection.

Polymerase chain reaction--restriction fragment length polymorphism analysis of clarithromycin-resistant Helicobacter pylori infection in children using stool sample.

BACKGROUND: To analyze clarithromycin-resistant Helicobacter pylori infection in children, we developed a method of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis using stool samples. MATERIALS AND METHODS: Twenty-three children without significant upper abdominal symptoms were included (mean age 7.0 years). Of these, 18 and five were diagnosed as H. pylori-positive and -negative, respectively, by the H. pylori stool antigen test (HpSA). The DNA from the stool samples was purified using the QIAamp DNA Stool Minikit (QIAGEN). The PCR was performed on the purified DNA using oligonucleotide primers designed to amplify the 23S rRNA gene of H. pylori. The PCR products were reacted with restriction enzymes MboII, BceAI, and BsaI to detect mutations A2142G, A2142C, and A2143G, respectively. RESULTS: Sixteen of the 18 HpSA-positive samples were PCR-positive, and all five HpSA-negative samples were PCR-negative. Thus, the PCR had 89% sensitivity and 100% specificity, with 91% accuracy in reference to HpSA. Of the 16 PCR-positive samples, one and four were digested with MboII and BsaI, respectively, indicating 31% prevalence of CAM-resistance. CONCLUSIONS: We conclude that the PCR-RFLP using stool samples is a rapid and reliable method to noninvasively detect clarithromycin-resistant H. pylori infection in children. It may be useful before choosing regimens of H. pylori eradication.

Helicobacter pylori infection in children with chronic idiopathic thrombocytopenic purpura.

BACKGROUND: Recently a high prevalence of Helicobacter pylori infection has been reported in adult patients with chronic idiopathic thrombocytopenic purpura (cITP). Furthermore, after H. pylori eradication therapy in such patients, their platelet counts have been observed to increase, suggesting that H. pylori may be a causative agent of adult cITP. However, there have been only a few reports of children with cITP. The purpose of the present paper was to examine the association between H. pylori infection and cITP in Japanese children. METHODS: Helicobacter pylori stool antigens (HpSA) were measured and the prevalence of H. pylori infection was determined in 10 children with cITP. RESULTS: Helicobacter pylori infection was found in only two of the subjects. In a boy, the urea breath test (UBT) was also positive and the patient received eradication therapy using amoxicillin, clarithromycin, and lansoprazole for 1 week. The therapy was successful and the patient's platelet count increased. The response was maintained throughout more than 1 year of follow up. CONCLUSIONS: The prevalence of H. pylori infection in children with cITP is not high. However, the platelet count increased after eradication therapy in a boy with cITP. It is suggested that the eradication of H. pylori infection would be valuable in children, as well as in adults, with cITP.

Evaluation of a urine antibody test for Helicobacter pylori in Japanese children.

OBJECTIVE: To evaluate the accuracy of a urine-based enzyme-linked immunosorbent assay (ELISA) kit for anti-Helicobacter pylori immunoglobulin G antibody (urine-HpELISA) in children, we compared its sensitivity and specificity in reference to (13)C-urea-breath test (UBT) and H pylori stool antigen test (HpSA). STUDY DESIGN: Japanese children without significant upper abdominal symptoms were included (n=100; mean age, 7.0 years; range, 2 to 15). UBT, HpSA, and urine-HpELISA were performed. RESULTS: Of 100 children, 36 and 64 were judged H pylori-positive and H pylori-negative, respectively, by UBT and HpSA. Thirty-four of 36 positive children were positive by urine-HpELISA, and 62 out of 64 negative children were negative by urine-HpELISA. Thus, the urine-HpELISA had 94.4% sensitivity and 96.9% specificity, with accuracy of 96.0%. CONCLUSIONS: The urine-HpELISA is a rapid, inexpensive, reliable, and easy-to-perform method for the diagnosis of H pylori infection in children. It may be useful not only for diagnosis but also for mass screening for epidemiological studies in pediatric population.

Serodiagnosis of Helicobacter pylori infection is not accurate for children aged below 10.

BACKGROUND: In order to investigate the immune response to Helicobacter pylori in childhood, we compared anti-H. pylori IgG and IgA antibodies with H. pylori antigen in the stool and examined the clinical usefulness of the anti-H. pylori IgG and IgA antibodies. METHODS: This study included 157 children who were seen at our hospital. Serum and stool samples were obtained for these children. Antibodies to H. pylori were examined using an H. pylori IgG enzyme-linked immunosorbent assays (ELISA) and an H. pylori IgA ELISA. Analysis of stool samples was carried out by the H. pylori stool antigen (HpSA) enzyme immunoassay. RESULTS: Of the 157 children, 45 children were HpSA positive, 110 were negative and two were undetermined. Out of 45 HpSA positive patients, 25 children were both IgG and IgA positive and seven were negative for both IgG and IgA antibodies. Of the 110 patients who were HpSA negative, 97 were negative for both antibodies. All HpSA positive children older than 10 years were positive for IgG and IgA antibodies, but of the HpSA positive children under the age of 10, only 18 out of 35 (51.4%) were positive for IgG antibodies or IgA antibody. CONCLUSION: These facts suggested that an immature immune response or tolerance to H. pylori exists in childhood and serodiagnosis of H. pylori infection is less useful in children aged below 10.