Helicobacter pylori-Associated Iron Deficiency Anemia in Childhood and Adolescence-Pathogenesis and Clinical Management Strategy.

Many epidemiological studies and meta-analyses show that persistent Helicobacter pylori infection in the gastric mucosa can lead to iron deficiency or iron deficiency anemia (IDA), particularly in certain populations of children and adolescents. Moreover, it has been demonstrated that H. pylori infection can lead to and be closely associated with recurrent and/or refractory iron deficiency and IDA. However, the pathogenesis and specific risk factors leading to this clinical outcome in H. pylori-infected children remain poorly understood. In general, most of pediatric patients with H. pylori-associated IDA do not show evidence of overt blood loss due to gastrointestinal hemorrhagic lesions. In adult populations, H. pylori atrophic gastritis is reported to cause impaired iron absorption due to impaired gastric acid secretion, which, subsequently, results in IDA. However, significant gastric atrophy, and the resultant substantial reduction in gastric acid secretion, has not been shown in H. pylori-infected children. Recently, it has been hypothesized that competition between H. pylori and humans for iron availability in the upper gastrointestinal tract could lead to IDA. Many genes, including those encoding major outer membrane proteins (OMPs), are known to be involved in iron-uptake mechanisms in H. pylori. Recent studies have been published that describe H. pylori virulence factors, including specific OMP genes that may be associated with the pathogenesis of IDA. Daily iron demand substantively increases in children as they begin pubertal development starting with the associated growth spurt, and this important physiological mechanism may play a synergistic role for the microorganisms as a host pathogenetic factor of IDA. Like in the most recent pediatric guidelines, a test-and-treat strategy in H. pylori infection should be considered, especially for children and adolescents in whom IDA is recurrent or refractory to iron supplementation and other definitive causes have not been identified. This review will focus on providing the evidence that supports a clear biological plausibility for H. pylori infection and iron deficiency, as well as IDA.

The Resolution of Severe Iron-Deficiency Anemia After Successful Eradication of Helicobacter pylori in Teenagers.

Long-term follow-up studies with Helicobacter pylori eradication therapy in children with H. pylori-associated iron-deficiency anemia (IDA) are scarce. We investigated whether successful H. pylori eradication would result in maintaining resolution of recurrent and/or refractory IDA in a cohort of teenagers in Japan. Methods: In this case series, 7 H. pylori-infected patients with recurrent and/or refractory IDA (12-16 y old) received successful eradication therapy and were then followed for a median of 20 months (range, 9-76 mo) after oral iron supplementation therapy (1-4 mo) was discontinued. Five patients of our study cohort participated in rigorous sports activities. Results: No visual appearance of ulcerations or erosions was found by esophagogastroduodenoscopy. In all patients studied, the gastric biopsies showed histological evidence of chronic gastritis without significant atrophy and intestinal metaplasia. Compared with the baseline (median values: hemoglobin, 6.3 g/dL; serum iron, 9 µg/dL; serum ferritin, 1.5 ng/mL), values of hemoglobin (P < 0.001), serum iron (P < 0.005), and ferritin (P < 0.001) significantly increased, on average, 2-3 months after eradication therapy and these iron indices were maintained at the same or higher levels at the endpoint of follow-up (median values: 14.2 g/dL, 102 µg/dL, and 29.3 ng/mL, respectively). No patient had recurrence of IDA at the time of final follow-up. Conclusions: H. pylori infection can be closely associated with recurrent or refractory IDA in teenage children. It is speculated that increased iron demands as a result of growth spurt in adolescents may play a synergistic role in combination with H. pylori in the pathogenesis of IDA.

[A Case of Mucinous Adenocarcinoma Extending to Bladder Neck and Prostate].

A 56-year-old man visited a clinic with the chief complaint of frequent micturition and residual sensation of urine. He was referred to our hospital for close examination. Cystoscopy showed a tumor protruding toward the bladder neck from the prostate with stones and debris on the surface. Magnetic resonance imaging showed an encapsulated tumor of iso-intensity in the prostate in T2-weighed images. Prostate specific antigen was 0.88 mg/dl. Transurethral resection of prostate was performed under the diagnosis of benign prostate hyperplasia. During the operation, a solid tumor with mucus deposit was observed. Intraoperative rapid pathological diagnosis was mucinous adenocarcinoma. A radical cystectomy was performed. Pathologically, mucinous adenocarcinoma was distributed in the bladder neck, the prostate and surrounding tissue, but the prostatic urethra was intact. The surgery was assessed to be curative. Neither neoadjuvant nor adjuvant chemotherapy was performed, since the effectiveness of chemotherapy for mucinous adenocarcinoma arising from urothelial epithelium has not been established.

The updated JSPGHAN guidelines for the management of Helicobacter pylori infection in childhood.

The Japan Pediatric Helicobacter pylori Study Group published the first guidelines on childhood H. pylori infection in 1997. They were later revised by the Japanese Society for Pediatric Gastroenterology, Hepatology and Nutrition (JSPGHAN). The H. pylori eradication rates, when employing triple therapy with amoxicillin and clarithromycin, currently recommended as the first-line therapy of H. pylori infection in Japan, have substantially decreased, creating an important clinical problem worldwide. In Japanese adults, the "test-and-treat" strategy for H. pylori infection is under consideration as an approach for gastric cancer prevention. However, the combined North American and European pediatric guidelines have rejected such a strategy for asymptomatic children. As risk for gastric cancer development is high in Japan, determining whether the "test-and-treat" strategy can be recommended in children has become an urgent matter. Accordingly, the JSPGHAN has produced a second revision of the H. pylori guidelines, which includes discussion about the issues mentioned above. They consist of 19 clinical questions and 34 statements. An H. pylori culture from gastric biopsies is recommended, not only as a diagnostic test for active infection but for antimicrobial susceptibility testing to optimize eradication therapy. Based upon antimicrobial susceptibility testing of H. pylori strains (especially involving clarithromycin), an eradication regimen including use of the antibiotics to which H. pylori is susceptible is recommended as the first-line therapy against H. pylori-associated diseases. The guidelines recommend against a "test-and-treat" strategy for H. pylori infection for asymptomatic children to protect against the development of gastric cancer because there has been no evidence supporting this strategy.

Results of triple eradication therapy in Japanese children: a retrospective multicenter study.

BACKGROUND: Large-scale clinical trials in children are lacking concerning Helicobacter pylori eradication therapies. The purpose of this study was to assess the efficacy of proton pump inhibitor (PPI)-based triple therapies in Japanese children. METHODS: This was a retrospective analysis of the first- and second-line PPI-based triple therapies from pediatric gastrointestinal units between 1996 and 2003. Data collected included doses and duration of regimens, drug compliance, success or failure of eradication, ulcer healing, and symptom response of those with dyspepsia and no ulcers. The results of antibiotic susceptibility tests were also reported in cases where these were performed. RESULTS: A total of 149 pediatric patients (mean age, 12.6 years) were studied, including 123 patients who received first-line therapy: 115 received a PPI plus amoxicillin and clarithromycin (PAC) and 8 received a PPI plus amoxicillin and metronidazole (PAM). Overall eradication rates of the first-line PAC and PAM therapies were 77.4% and 87.5%, respectively ( P = 0.68). All 14 patients with failed PAC therapy received the second-line PAM regimen, resulting in an eradication rate of 100%. Mild side effects were reported only in PAC regimens (13.8%). Primary resistance to amoxicillin, clarithromycin, and metronidazole was detected in 0%, 34.7%, and 12.5% of the strains, respectively. The PAC regimen showed a high eradication rate for clarithromycin-susceptible strains (91.7%), but was relatively ineffective for resistant strains (40.0%) ( P < 0.01). Eradication of H. pylori was associated with ulcer healing and symptomatic improvement among those with gastritis only (both; P < 0.001). Among 17 patients with iron-deficiency anemia, post-treatment hemoglobin levels were higher than the pretreatment levels ( P < 0.001). CONCLUSIONS: The PAC regimen is effective in children. Clarithromycin resistance is associated with eradication failure. Metronidazole is a good substitute for clarithromycin as the second-line option for children.

Wild-type phenylalanine hydroxylase activity is enhanced by tetrahydrobiopterin supplementation in vivo: an implication for therapeutic basis of tetrahydrobiopterin-responsive phenylalanine hydroxylase deficiency.

We previously proposed a novel disease entity, tetrahydrobiopterin (BH4)-responsive phenylalanine hydroxylase (PAH) deficiency, in which administration of BH4 reduced elevated levels of serum phenylalanine [J. Pediatr. 135 (1999) 375-378]. Subsequent reports indicate that the prevalence of BH4-responsive PAH deficiency is much higher than initially anticipated. Although growing attention surrounds treatment with BH4, little is known about the mechanism of BH4 responsiveness. An early report indicates that BH4 concentration in rat liver was 5 microM where Km for BH4 of rat PAH was estimated to be 25 microM in an oxidation experiment using a liver slice, suggesting relative insufficiency of BH4 in liver in vivo. In the present study, we developed a breath test for mice using [1-13C]phenylalanine in order to examine the BH4 responsiveness of normal PAH in vivo. The reliability of the test was verified using BTBR mice and its mutant strain lacking PAH activity, Pahenu2. BH4 supplementation significantly enhanced 13CO2 production in C57BL/6 mice when phenylalanine was pre-loaded. Furthermore, BH4 apparently activated PAH in just 5 min. These observations suggest that submaximal PAH activity occurs at the physiological concentrations of BH4 in vivo, and that PAH activity can be rapidly enhanced by supplementation with BH4. Thus, we propose a possible hypothesis that the responsiveness to BH4 in patients with PAH deficiency is due to the fact that suboptimal physiological concentrations of BH4 are normally present in hepatocytes and the enhancement of the residual activity may be associated with a wide range of mutations.