1.
Helicobacter pylori and hematological disorders.
Santambrogio, E, Orsucci, L
Minerva gastroenterologica e dietologica. 2019;(3):204-213
Abstract
Helicobacter pylori (H. pylori) is one of the most common worldwide infections, which can affect both adults and children. The prevalence of this bacterium is variable in different countries, depending on various hygienic and socioeconomic conditions and living customs. The major damaged tissues of the infection are in the upper gastrointestinal tract, causing gastritis, gastric and duodenal ulcer and gastrointestinal malignancy. Nevertheless, other disorders are associated with this pathogen, including several hematological diseases, such as iron deficiency anemia, immune thrombocytopenia and vitamin B12 deficiency. A huge of data in literature support these associations, enough to recognize them in the last Maastricht V/Florence Consensus Report by European Study Group. The pathogenic mechanisms underlying the linkage between H. pylori and these hematological disorders are not clearly identified, but certainly the good hematological response reaches after eradication therapy confirm a central role of the bacterium in this scenario. Instead, the pathogenic mechanisms of H. pylori infection, which lead to the occurrence of mucosa-associated lymphoid tissue (MALT) lymphoma are clearer and more consolidated; so much that nowadays eradication therapy alone represents the only treatment in this disorder, when localized and with a concomitant H. pylori infection. This review focuses on the hematologic diseases related to H. pylori, particularly on iron deficiency anemia, vitamin B12 deficiency, immune thrombocytopenia and gastric MALT lymphoma.
2.
Biological properties and pathogenicity factors of Helicobacter pylori.
Isaeva, GS, Fagoonee, S
Minerva gastroenterologica e dietologica. 2018;(3):255-266
Abstract
The unexpected discovery of Helicobacter pylori (H. pylori) has revolutionised the history of microbiology as well as of gastroenterology in the last 30 years, with an invaluable benefit for millions of persons worldwide. The confirmation that this Gram-negative spiral bacterium could live in the stomach has rendered out-of-date the concept of inhospitality of micro-organisms in the gastric environment, after a long history of unheard reports on the presence of spiral bacteria in the stomach. The pathogenicity of H. pylori depends on its ability to colonize as well as the capability to survive in the harsh gastric environment. This is possible by a coevolution between the pathogen itself and the host. Any perturbation of this equilibrium disrupts the host-pathogen interaction, promoting the pathological effects. H. pylori has a wide range of pathogenicity factors, in particular cytotoxins, enzymes of aggression, and factors providing protection against human defense systems. The most well-characterized cytotoxins contributing to epithelial cell damage are the vacuolating cytotoxin A (VacA) and the cytotoxin-associated gene A (CagA). Only detailed knowledge of the microbiology and genomics of H. pylori infection will allow a vaccine to be produced. Today, we know that H. pylori induces strong humoral and cellular immune responses, but these are incapable of eliminating the bacterium, raising doubts about the possibility of developing an effective vaccine easily. This review highlights microbiological findings concerning H. pylori infection, focusing on colonization, survival and pathogenicity.
3.
Current status of Helicobacter pylori association with haematological and cardiovascular diseases: A mini review.
Muhammad, JS, Zaidi, SF, Saeed, SA, Ishaq, M
JPMA. The Journal of the Pakistan Medical Association. 2017;(6):907-911
Abstract
Helicobacter pylori infection is considered the most commonly prevalent gastrointestinal pathogen where it manages to survive despite the hostile environment of human stomach, leading to various gastric diseases including gastric cancer. Due to the chronic inflammatory state induced by H. pylori and its interaction with host immune system have diverted researchers to investigate its correlation with systemic diseases outside of the gastrointestinal tract. This literature review was done to explore the association of H. pylori infection with haematological and cardiovascular diseases. We used medical subject heading (MeSH) terms "Helicobacter pylori" with "inflammation," "haematological diseases," "coronary heart diseases" or "vascular diseases" to search PubMed database. All relevant studies identified from 2005 to 2015 were included. As many of the studies are small-scale or showed weak association, further studies are needed to address the role of H. pylori in pathogenesis of haematological and cardiovascular diseases.