Remission of primary low-grade gastric lymphomas of the mucosa-associated lymphoid tissue type in immunocompromised pediatric patients

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.

Primary gastric lymphoma: A report of 16 pediatric cases treated at a single institute and review of the literature

Gastrointestinal tract is the most common extranodal site for childhood non-Hodgkin lymphomas (NHLs). However, primary gastric lymphoma (PGL) is very rare. We report our experience with PGL. Between 1972 and 2019, patients with PGL among 1696 NHL cases were evaluated retrospectively. Patient characteristics, treatments, and survival rates were recorded. We also reviewed the cases reported in literature. There were 16 PGL (11 males, five females) cases with a median age of 10 years. Most frequent complaints, similarly to the literature, were pain and vomiting. Hematemesis/melena and anemia were present in 20% of patients. Most common tumor location was antrum. Histopathological subtypes were Burkitt and non-Burkitt B-cell lymphoma in 43.75% and marginal zone lymphoma (MZL) in 6.25% of cases while mucosa-associated lymphoid tissue (MALT) and low-grade lymphomas constitute 15.3% of cases reported in the literature. In our series, Helicobacter pylori (H. pylori) was analyzed in only the case with MZL and found to be positive. However, H. pylori positivity was reported in 75% of the cases in the literature. H. pylori eradication, chemotherapy, and radiotherapy were applied in one, 14, and five patients. Subtotal gastrectomy with gastroduodenostomy/jejunostomy was performed in three patients. Gastrojejunostomy was done without tumor resection in two patients. Nine patients lived without disease for a median of 59 (12-252) months. Five-year EFS and OS were 69.6% and 64.3%, respectively. PGL constitutes 0.94% of our NHL cases. Interestingly, most of the cases in the literature were from Turkey. While adult PGL is mostly MALT lymphoma, most pediatric cases had high-grade histopathology. Although surgery and radiotherapy were applied earlier, chemotherapy alone is sufficient.

New Diagnostic Strategies for Detection of Helicobacter pylori Infection in Pediatric Patients

Helicobacter pylori (H pylori) is a common chronic bacterial infection that is an important cause of peptic ulcer disease and gastroduodenal disease in children. H pylori is also associated with extragastric manifestations, including growth reduction, iron-deficiency anemia, and idiopathic thrombocytopenic purpura. Current guidelines recommend endoscopy with biopsy for the definitive demonstration of H pylori infection. In contrast to serology, the fecal antigen test and the urea breath test provide reliable, sensitive, and specific results for detecting active H pylori infection in children before and after treatment. The first-line treatment option for pediatric patients is triple therapy with a proton pump inhibitor and 2 antibiotics, which include amoxicillin and clarithromycin or metronidazole. Decreasing eradication rates and the emergence of antibiotic-resistant strains of H pylori have led to the use of other treatments, such as sequential therapy or triple therapy with newer antibiotics, particularly in geographic areas with high rates of antibiotic resistance. Patients should be tested after treatment to confirm eradication, as the absence of symptoms does not necessarily mean that H pylori is no longer present. This clinical roundtable monograph provides an overview of H pylori infection, as well as expert insight into the diagnosis and management of H pylori infection in children.

Childhood cancers: what is a possible role of infectious agents?

The etiology of childhood cancers has been studied for more than 40 years. However, most if not all cancers occurring in children are attributed to unknown causes. This review is focused on the role of infections in cancer development and progression in children. The main infectious agents include human herpesviruses, polyoma viruses, and human papilloma viruses. It is known that infections can lead to carcinogenesis through various mechanisms, and most likely act in addition to genetic and environmental factors. Given the importance of the infectious etiology of childhood cancers, clinical implications and possible prevention strategies are discussed.

What do we know about benefits of H. pylori treatment in childhood?

Policy analysis shows that H. pylori test and treat strategies targeting adults at moderate to high risk of H. pylori-induced disease is likely to be cost-effective for preventing digestive diseases responsible for a large global disease burden. Little is known, however, about health benefits to children from eliminating this infection. We conducted a systematic review of the evidence regarding health benefits to children from treatment to eliminate H. pylori infection.   We systematically searched Ovid MEDLINE for pertinent review articles published through 2012. We excluded reviews focused on treatment efficacy and scrutinized reference lists of selected reviews to identify additional eligible reviews. Fifteen reviews met specified inclusion criteria. Overall, they show that few reported studies investigating pediatric health effects of treatment for H. pylori infection were well designed with adequate statistical power. Thus, there is insufficient evidence for drawing conclusions about health benefits to children from treatment to eliminate H. pylori infection.

Endoscopic and histologic analysis of gastric mucosa-associated lymphoid tissue in children with Helicobacter pylori infection

OBJECTIVES

Nodular gastritis (NG) associated with Helicobacter pylori infection can occur commonly in childhood and is regarded to be benign without clinical significance. This study includes endoscopic and histologic analysis of gastric mucosa-associated lymphoid tissue (MALT) to clarify the significance of NG on endoscopy in H pylori-infected children.

METHODS

Of the 758 children who underwent endoscopy, 80 were identified as having H pylori infection. These patients were divided into 3 groups based on endoscopic severity of gastric nodularity. Histopathologic grading of MALT and immunohistochemistry of CD3, CD20, cytokeratin, and Ki-67 were evaluated.

RESULTS

On endoscopy, severe NG was observed in the antrum of 38 of the 80 subjects, mild NG in 27, and an absence of NG in 15. Density of H pylori and lymphocyte infiltration differed among the 3 groups (P=0.022 and P=0.025, respectively). Histological grading for gastric lymphoid infiltrates was compatible with grade 1 in 47 (58.8%), grade 2 in 21 (26.3%), grade 3 in 7 (8.8%), and grade 4-5 in 4 (5.1%) in the antrum. Degree of NG, density of H pylori, neutrophil activity, and gastritis score in the antrum varied with MALT grades (P=0.003, P=0.042, P=0.028, and P=0.006, respectively).

CONCLUSIONS

Our study suggests NG may present as a significant gastric manifestation of childhood H pylori infection that indicates gastric MALT. Thorough histologic investigation may be useful in the evaluation of gastric MALT in children infected with H pylori that manifests as severe NG in the antrum.

Consequences of Helicobacter pylori infection in children

Although evidence is emerging that the prevalence of Helicobacter pylori (H. pylori) is declining in all age groups, the understanding of its disease spectrum continues to evolve. If untreated, H. pylori infection is lifelong. Although H. pylori typically colonizes the human stomach for many decades without adverse consequences, children infected with H. pylori can manifest gastrointestinal diseases. Controversy persists regarding testing (and treating) for H. pylori infection in children with recurrent abdominal pain, chronic idiopathic thrombocytopenia, and poor growth. There is evidence of the role of H. pylori in childhood iron deficiency anemia, but the results are not conclusive. The possibility of an inverse relationship between H. pylori and gastroesophageal reflux disease, as well as childhood asthma, remains a controversial question. A better understanding of the H. pylori disease spectrum in childhood should lead to clearer recommendations about testing for and treating H. pylori infection in children who are more likely to develop clinical sequelae.

Ileal Mucosa-Associated Lymphoid Tissue (MALT) Lymphoma with a Large-Cell Component That Regressed Spontaneously

Reported herein is a case of mucosa-associated lymphoid tissue (MALT) lymphoma of the terminal ileum with a large-cell component, which regressed spontaneously. To the best of our knowledge, only five cases of spontaneously regressing MALT lymphoma have been reported in the English-language literature, and all of these cases were low-grade lymphomas. Spontaneous regression of a MALT lymphoma with a high-grade component is very rare. The present case suggests that MALT lymphoma cells have a reversible nature, even in the presence of a high-grade component.

Helicobacter pylori infection in pediatrics

During the last year, epidemiologic studies have shown that spontaneous clearance of Helicobacter pylori infection has a less significant role in countries with high prevalence and, in contrast to adults, there is no male predominance of H. pylori infection in children. Early acquisition of H. pylori may play a role in the development of recurrent abdominal pain in children less than 5 years of age. In this very young age group, the adequate performance of stool antigen test and (13)C urea-breath test demonstrated satisfactory sensitivity and specificity as non-invasive methods to diagnose H. pylori infection. In the current paper, the most relevant pediatric studies on H. pylori infection published between April 2006 and March 2007 are reviewed.