HELICOBACTER PYLORI AND t(11;18)(q21;q21) TRANSLOCATION IN GASTRIC MALT LYMPHOMA

Role of non-Helicobacter pylori gastric Helicobacters in helicobacter pylori-negative gastric mucosa-associated lymphoid tissue lymphoma

Marginal zone lymphomas rank as the third most prevalent form of non-Hodgkin B-cell lymphoma, trailing behind diffuse large B-cell lymphoma and follicular lymphoma. Gastric mucosa-associated lymphoid tissue lymphoma (GML) is a low-grade B-cell neoplasia frequently correlated with Helicobacter pylori (H. pylori)-induced chronic gastritis. On the other hand, a specific subset of individuals diagnosed with GML does not exhibit H. pylori infection. In contrast to its H. pylori-positive counterpart, it was previously believed that H. pylori-negative GML was less likely to respond to antimicrobial therapy. Despite this, surprisingly, in-creasing evidence supports that a considerable proportion of patients with H. pylori-negative GML show complete histopathological remission after bacterial eradication therapy. Nonetheless, the precise mechanisms underlying this treatment responsiveness are not yet fully comprehended. In recent years, there has been growing interest in investigating the role of non-H. pylori gastric helicobacters (NHPHs) in the pathogenesis of H. pylori-negative GML. However, additional research is required to establish the causal relationship between NHPHs and GML. In this minireview, we examined the current understanding and proposed prospects on the involvement of NHPHs in H. pylori-negative GML, as well as their potential response to bacterial eradication therapy.

Effectiveness of Helicobacter pylori eradication in the treatment of early-stage gastric mucosa-associated lymphoid tissue lymphoma: An up-to-date meta-analysis

BACKGROUND

Gastric mucosa-associated lymphoid tissue (MALT) lymphoma (GML) is usually a low-grade B-cell neoplasia strongly associated with Helicobacter pylori (H. pylori)-induced chronic gastritis. Clinical practice guidelines currently recommend H. pylori eradication as the preferred initial treatment for early-stage GML. To determine the practical effect of bacterial eradication as the sole initial therapy for early-stage GML, an updated analysis and review of available evidence is imperative.

AIM

To perform a meta-analysis to assess the rate of complete remission (CR) of H. pylori-positive early-stage GML following bacterial eradication.

METHODS

We performed independent, computer-assisted literature searches using the PubMed/MEDLINE, Embase, and Cochrane Central databases through September 2022. Prospective and retrospective observational studies evaluating the CR of early-stage GML following bacterial eradication in H. pylori-positive patients. The risk of bias was assessed using Joanna Briggs Institute (JBI) Critical Appraisal Tools. The pooled estimate of the complete histopathological remission rate and respective confidence intervals (95%CI) were calculated following the random-effects model. Heterogeneity and inconsistency were assessed using Cochran's Q test and I2 statistic, and heterogeneity was defined as P < 0.01 and I² > 50%, respectively. Subgroup and meta-regression analyses were conducted to explore potential sources of heterogeneity.

RESULTS

The titles and abstracts of 1576 studies were screened; 96 articles were retrieved and selected for full-text reading. Finally, 61 studies were included in the proportional meta-analysis (P-MA). Forty-six were prospective and fifteen were retrospective uncontrolled, single-arm, observational studies. The overall risk of bias was low to moderate in all but a single report, with an average critical appraisal score across all studies of 79.02%. A total of 2936 H. pylori-positive early-stage GML patients, in whom H. pylori was successfully eradicated, were included in the analysis. The pooled CR of H. pylori-positive early-stage GML after bacterial eradication was 75.18% (95%CI: 70.45%-79.91%). P-MA indicated the substantial heterogeneity in CR reported across studies (I 2 = 92%; P < 0.01). Meta-regression analysis identified statistically significant effect modifiers, including the proportion of patients with t(11;18)(q21;q21)-positive GML and the risk of bias in each study.

CONCLUSION

Comprehensive synthesis of available evidence suggests that H. pylori eradication is effective as the sole initial therapy for early-stage GML. Although the substantial heterogeneity observed across studies limits the interpretation of the pooled overall CR, the present study is a relevant to informing clinical practice.

Efficacy of eradication therapy in Helicobacter pylori-negative gastric mucosa-associated lymphoid tissue lymphoma: A meta-analysis

BACKGROUND AND AIMS

The role of eradication therapy in Helicobacter pylori-negative gastric mucosa-associated lymphoid tissue (MALT) lymphoma remains controversial. The aim of this study was to investigate the efficacy of H. pylori eradication therapy as a first-line treatment for H. pylori-negative gastric MALT lymphoma.

METHODS

A literature search of studies published until October 2019 was performed using electronic databases. Studies that reported treatment response to eradication therapy as an initial treatment for patients with H. pylori-negative gastric MALT lymphoma were eligible for inclusion. The primary outcome was the complete remission rate after eradication therapy.

RESULTS

Twenty-five studies were included in the analyses. The overall pooled complete remission rate was 29.3% (95% confidence interval [CI], 22.2%-37.4%, I²  = 41.5%). There was no publication bias, and the sensitivity analyses showed consistent results. The pooled complete remission rates were lower in the subgroups of studies that had a higher incidence of translocation t(11;18)(q21;q21) (19.9%, 95% CI, 11.6%-32.0%), studies that used serological tests to exclude H. pylori infection (27.5%, 95% CI, 20.1%-36.4%), and studies where non-response to eradication therapy was determined at <12 months after treatment (27.0%, 95% CI, 15.5%-42.7%). Meta-regression analysis revealed that the pooled estimate was not significantly different in terms of the characteristics of individual studies.

CONCLUSIONS

Although the complete remission rate after eradication therapy is not high, it can be used as an initial treatment option in a subset of patients with H. pylori-negative gastric MALT lymphoma. Further studies to identify subgroups of patients who may benefit from eradication therapy are needed.

IVTH BRAZILIAN CONSENSUS CONFERENCE ON HELICOBACTER PYLORI INFECTION

ABSTRACT Significant progress has been obtained since the III Brazilian Consensus Conference on H. pylori infection held in 2012, in Bento Gonçalves, Brazil, and justify a fourth meeting to establish updated guidelines on the current management of H. pylori infection. Therefore, the Núcleo Brasileiro para Estudo do Helicobacter pylori e Microbiota (NBEHPM), association linked to Brazilian Federation of Gastroenterology (FBG) held its fourth meeting again in Bento Gonçalves, RS, Brazil, on August 25-27, 2017. Twenty-six delegates, including gastroenterologists, endoscopists, and pathologists from the five regions of Brazil as well as one international guest from the United States, participated in the meeting. The participants were invited based on their knowledge and contribution to the study of H. pylori infection. The meeting sought to review different aspects of treatment for infection; establish a correlation between infection, dyspepsia, intestinal microbiota changes, and other disorders with a special emphasis on gastric cancer; and reassess the epidemiological and diagnostic aspects of H. pylori infection. Participants were allocated into four groups as follows: 1) Epidemiology and Diagnosis, 2) Dyspepsia, intestinal microbiota and other afections, 3) Gastric Cancer, and, 4) Treatment. Before the consensus meeting, participants received a topic to be discussed and prepared a document containing a recent literature review and statements that should be discussed and eventually modified during the face-to-face meeting. All statements were evaluated in two rounds of voting. Initially, each participant discussed the document and statements with his group for possible modifications and voting. Subsequently, during a second voting in a plenary session in the presence of all participants, the statements were voted upon and eventually modified. The participants could vote using five alternatives: 1) strongly agree; 2) partially agree; 3) undecided; 4) disagree; and 5) strongly disagree. The adopted consensus index was that 80% of the participants responded that they strongly or partially agreed with each statement. The recommendations reported are intended to provide the most current and relevant evidences to management of H. pylori infection in adult population in Brazil.

Evaluation of the clinical characteristics, management, and prognosis of 103 patients with gastric mucosa-associated lymphoid tissue lymphoma

The diagnosis of gastric mucosa-associated lymphoid tissue (MALT) lymphoma is difficult owing to its non-specific symptoms and various endoscopic findings. Treatments such as radiotherapy (RT) for localized and chemotherapy (CT) for advanced stages of the disease are employed. The aim of the present study was to examine the clinical characteristics and prognostic factors of Helicobacter pylori (H. pylori) eradication (HPE) in patients with gastric MALT lymphoma. The medical records of 103 patients with gastric MALT lymphoma for the period 2001–2013, were analyzed. The 103 median age of the patients was 53 years and the male to female ratio was 1:1. Serum lactate dehydrogenase and β2-microglobulin were within normal range. Macroscopically, the most commonly involved site was the antrum, followed by the corpus and fundus. A total of 97 patients (94%) tested positive for H. pylori. Forty patients (39%) had stage I, 35 patients (35%) had local or distant nodal involvement, 20 of 103 patients had stage IIIE (19%) and 8 of 103 patients had stage IV (7%) disease. Complete remission, after HPE, was achieved in 54 of the 69 patients (78%) that were H. pylori-positive and in 2 of the 4 patients (50%) that were H. pylori-negative. HPE had a superior trend in the H. pylori-positive patients although no significant difference was identified in the two groups (p=0.194). In patients with advanced disease, the 5-year progression-free survival (PFS) and overall survival (OS) estimates were significantly improoved for patients receiving HPE with CT or RT than those receiving CT or RT (p=0.046 and 0.035, respectively). The multivariate analysis revealed that, the advanced stages were independently associated with shorter PFS, and the modified-International Prognostic Index (m-IPI) (≥2) was associated with shorter OS. In conclusion, gastric MALT lymphoma had a favorable outcome with a high OS rate. HPE was an effective treatment for gastric MALT lymphoma. The patients with advanced stages and m-IPI (≥2) had a much worse prognosis.

The first case of human autochtonous subconjunctival dirofilariosis in Poland and MALT lymphoma as possible consequence of this parasitosis

The first case of human dirofilarosis in Poland was recorded in 2007. Until that time our country was free of Dirofilaria repens. Recent studies show that 21,4- 60% of dogs in Warsaw region harbour microfilariae, therefore it is becoming a growing problem in Central Europe.

In April 2013 a subconjunctival D. repens was removed from the eye of 61-year-old woman. It was the twenty first case of this disease in Poland, the third case of eye dirofilaria and the fourth autochtonous case. The patient had never been abroad, so it was the first case of autochtonous human ocular dirofilariosis in Poland. Nine months after the D. repens had been removed, a MALT lymphoma was discovered. In the article we discuss whether a MALT lymphoma of the lacrimal gland of the eye, previously affected by the parasite, may be the consequence of the invasion.