RESUMO
BACKGROUND: Gastric cancer (GC) is considered a silent killer, taking more than three quarters of a million lives annually. Therefore, prior to further costly and invasive diagnostic approaches, an initial GC risk screening is desperately in demand. METHODS: In order to develop a simple risk scoring system, the demographic and lifestyle indices from 858 GC and 1132 non-ulcer dyspeptic (NUD) patients were analysed. We applied a multivariate logistic regression approach to identify the association between our target predictors and GC versus NUD. The model performance in classification was assessed by receiver operating characteristic (ROC) analysis. Our questionnaire covering 64 predictors, included known risk factors, such as demographic features, dietary habits, self-reported medical status, narcotics use, and SES indicators. RESULTS: Our model segregated GC from NUD patients with the sensitivity, specificity, and accuracy rates of 85.89, 63.9, and 73.03%, respectively, which was confirmed in the development dataset (AUC equal to 86.37%, P < 0.0001). Predictors which contributed most to our GC risk calculator, based on risk scores (RS) and shared percentages (SP), included: 1) older age group [> 70 (RS:+ 241, SP:7.23), 60-70 (RS:+ 221, SP:6.60), 50-60 (RS:+ 134, SP:4.02), 2) history of gastrointestinal cancers (RS:+ 173, SP:5.19), 3) male gender (RS:+ 119, SP:3.55), 4) non-Fars ethnicity (RS:+ 89, SP:2.66), 5) illiteracy of both parents (RS:+ 78, SP:2.38), 6) rural residence (RS:+ 77, SP:2.3), and modifiable dietary behaviors (RS:+ 32 to + 53, SP:0.96 to 1.58). CONCLUSION: Our developed risk calculator provides a primary screening step, prior to the subsequent costly and invasive measures. Furthermore, public awareness regarding modifiable risk predictors may encourage and promote lifestyle adjustments and healthy behaviours.
Assuntos
Dispepsia , Neoplasias Gástricas , Humanos , Masculino , Idoso , Neoplasias Gástricas/diagnóstico , Irã (Geográfico) , Dispepsia/diagnóstico , Inquéritos e QuestionáriosRESUMO
INTRODUCTION: Helicobacter pylori express a large array of antigens, each of which is duly responsible for successful colonization and pathogenesis. Here, we have studied host serum antibody responses to four of its immunodominant antigens in association with the infection status and the resulting clinical outcomes. METHODS: For this purpose, four individual H. pylori proteins (UreB, CagA, Tip-α and HP0175) were produced in recombinant forms. Serum antibody responses of 246 (75â¯GC and 171 NUD) patients, against the above antigens, were evaluated by multiplex immunoblotting. The associations between the resulting data and the infection status, as well as clinical outcomes were evaluated using logistic regression models. RESULTS: Serum antibodies to all four recombinant antigens increased the chances of detecting screening ELISA-positive subjects, in an escalating dose-dependent manner, ranging from 2.6 (1.5-4.7) for HP0175 to 14.3 for UreB (4.3-50.7), exhibiting the lowest and highest odds ratios, respectively (PAdjâ¯≤â¯0.001), such that 98.2% of the subjects with antibodies to all four antigens, were also positive by the screening ELISA (Pâ¯<â¯0.0001). Among the screening ELISA-positive subjects, the three antigens of CagA, Tip-α, and HP0175 were able to segregate current from past H. pylori infection (Pâ¯<â¯0.05). Accordingly, subjects with antibodies to one or more antigen(s) were at 5.4 (95% CI: 1.8-16.4) folds increased chances of having current infection, as compared to triple negatives (PAdjâ¯=â¯0.003). In reference to the clinical outcomes, those with serum antibodies to CagA were more prevalent among gastric cancer, as compared to NUD patients (ORAdj: 5.4, 95% CI: 2.4-12.2, PAdjâ¯<â¯0.0001). When NUD patients were categorized according to their histopathologic status, multiple antigen analysis revealed that subjects with serum antibodies to one or more of the 3 current infection-positive antigens (CagA, Tip-α, and HP0175) were at 9.7 (95% CI: 2.1-44.9, Pâ¯=â¯0.004) folds increased risk of atrophic gastritis, in reference to triple negatives. CONCLUSION: The non-invasive multiplex serology assay, presented here, was able to not only detect subjects with current H. pylori infection, it could also screen dyspeptic patients for the presence of gastric atrophy. This simple and cost-efficient method can supplement routine screening ELISAs, to increase the chances of detecting current infections as well as atrophic gastritis.
Assuntos
Antígenos de Bactérias/imunologia , Antígenos de Bactérias/isolamento & purificação , Proteínas de Bactérias/imunologia , Gastrite Atrófica/microbiologia , Infecções por Helicobacter/imunologia , Helicobacter pylori/imunologia , Testes Sorológicos/métodos , Adulto , Idoso , Anticorpos Antibacterianos/sangue , Antígenos de Bactérias/genética , Proteínas de Bactérias/genética , Feminino , Gastrite Atrófica/patologia , Infecções por Helicobacter/epidemiologia , Infecções por Helicobacter/microbiologia , Helicobacter pylori/genética , Helicobacter pylori/patogenicidade , Humanos , Irã (Geográfico) , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/isolamento & purificação , Neoplasias Gástricas/imunologia , Neoplasias Gástricas/microbiologia , Transativadores/genética , Transativadores/imunologiaRESUMO
BACKGROUND: Most two- dimensional in vitro models for studying host- H. pylori interactions rely on tumor-derived cell lines, which harbor malignant alterations. The recent development of human gastric organoids has overcome this limitation and provides a highly sophisticated, yet costly, short-term model for H. pylori infection, with restricted use in low-budget centers. METHOD: Tissue specimens from upper, middle, and lower stomachs of H. pylori-negative volunteers were collectively dispersed and cultured on mouse embryonic fibroblast (MEF) or collagen-coated plates. Gastric primary cells (GPCs) were evaluated by light microscopy, immunostaining, qRT-PCR and ELISA analysis of cellular secretions, before and after H. pylori infection. RESULTS: The formation and long-term (up to 1 year) maintenance of GPCs was highly dependent on adherent inactivated MEF cells, cultured in enriched media. These cells were multipassageable and able to undergo stable freezer storage and subsequent revival. The cellular composition of GPCs included the combination of cytokeratin 18 (CK18) and E-cadherin (E-cad)-positive epithelial cells, MUC5AC-positive gastric cells, and leucine-rich repeat containing G protein-coupled receptor 5 (LGR5)-positive progenitor cells. These cells produced significant amounts of gastric pepsinogens I and II. GPCs also allowed for extended (up to 96 hours) H. pylori infection, during which they underwent morphological alterations (cellular vacuolation and elongation) and hyperproduction of gastric pepsinogens and inflammatory cytokines (IL-8 and TNF-α). CONCLUSION: We, hereby, present a simple, consistent, and cost-efficient gastric cell culture system, which provides a suitable model for extended in vitro infection of H. pylori. This platform can be employed for a variety of gastric-related research.
Assuntos
Infecções por Helicobacter/microbiologia , Helicobacter pylori/crescimento & desenvolvimento , Cultura Primária de Células/métodos , Estômago/citologia , Animais , Caderinas/genética , Caderinas/metabolismo , Células Cultivadas , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Infecções por Helicobacter/metabolismo , Helicobacter pylori/fisiologia , Humanos , Queratina-18/genética , Queratina-18/metabolismo , Camundongos , Modelos Biológicos , Organoides/citologia , Organoides/microbiologia , Cultura Primária de Células/economia , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Estômago/microbiologia , Fator de Necrose Tumoral alfaRESUMO
Immunotoxins (ITs) are specialized therapeutic agents designed for targeted treatment, particularly in cancer therapy. They consist of a monoclonal antibody or antibody fragment linked to a potent cytotoxic agent, such as bacterial- or plant-derived toxins like diphtheria toxin, ricin, or pseudomonas exotoxin. The monoclonal antibody component specifically binds to antigens expressed on the surface of target cells, facilitating the internalization of the IT. Once inside the cell, the cytotoxic agent is released, disrupting essential cellular processes and leading to cell death. This targeted approach minimizes damage to healthy tissues while effectively eliminating diseased cells. The production of ITs involves two primary methods: recombinant fusion and chemical conjugation. In recombinant fusion, genetic engineering is used to create a fusion protein that combines the antibody and toxin, ensuring precise control over their ratio and functionality. In chemical conjugation, pre-existing antibodies are chemically linked to toxins, allowing for greater flexibility in combining different antibodies and cytotoxic agents. Each method has its advantages and challenges, influencing the specificity, production complexity, and therapeutic potential of the resulting ITs. As research advances, ITs continue to show promise not only in oncology but also in treating other diseases, including inflammatory conditions and atherosclerosis. The precise targeting and potent effects of ITs make them a valuable tool in the development of new therapeutic strategies.
Assuntos
Imunotoxinas , Neoplasias , Imunotoxinas/uso terapêutico , Humanos , Neoplasias/terapia , Neoplasias/imunologia , Neoplasias/tratamento farmacológico , Medicina de Precisão/métodos , Anticorpos Monoclonais/uso terapêutico , AnimaisRESUMO
BACKGROUND AND AIMS: Helicobacter pylori is a highly diverse pathogen, which encounters epithelial cells as the initial defense barrier during its lifelong infection. The structure of epithelial cells can be disrupted through cleavage of microfilaments. Cytokeratin 18 (CK18) is an intermediate filament, the cleavage of which is considered an early event during apoptosis following activation of effector caspases. METHODS: Helicobacter pylori strains were isolated from 76 dyspeptic patients. cagA 3' variable region and CagA protein status were analyzed by PCR and western blotting, respectively. Eight hours post-co-culture of AGS cells with different H. pylori strains, flow cytometric analysis was performed using M30 monoclonal antibody specific to CK18 cleavage-induced neo-epitope. RESULTS: Higher rates of CK18 cleavage were detected during co-culture of AGS cells with H. pylori strains bearing greater numbers of cagA EPIYA-C and multimerization (CM) motifs. On the other hand, H. pylori strains with greater numbers of EPIYA-B relative to EPIYA-C demonstrated a decrease in CK18 cleavage rate. Thus, H. pylori-mediated cleavage of CK18 appeared proportional to the number of CagA EPIYA-C and CM motifs, which seemed to be downplayed in the presence of EPIYA-B motifs. CONCLUSIONS: Our observation associating the heterogeneity of cagA variants with the potential of H. pylori strains in the induction of CK18 cleavage as an early indication of apoptosis in gastric epithelial cells supports the fact that apoptosis may be a type-specific trait. However, additional cagA-targeted experiments are required to clearly identify the role of EPIYA and CM motifs in apoptosis and/or the responsible effector molecules.
Assuntos
Motivos de Aminoácidos , Antígenos de Bactérias/genética , Apoptose , Proteínas de Bactérias/genética , Células Epiteliais/microbiologia , Helicobacter pylori/patogenicidade , Queratina-18/metabolismo , Western Blotting , Células Cultivadas , Técnicas de Cocultura , Citometria de Fluxo , Helicobacter pylori/genética , Humanos , Reação em Cadeia da Polimerase , Polimorfismo GenéticoRESUMO
BACKGROUND/AIM: The identification of the vacA intermediate region has provided new insights into the role of vacA heterogeneity in relation to gastro-duodenal pathogenesis. The aim of this study was to assess vacA polymorphism in Iranian Helicobacter pylori strains and its association with cagA as a major virulence determinant, gastric histopathology and disease. METHODS: vacA polymorphism and serum antibody responses were studied in 207 H. pylori-infected (139 NUD, 34 PUD, and 34 GC) patients and correlated with gastric histopathology. RESULTS: Multivariate logistic regression analysis found intermediate region typing superior to signal or mid region typing for screening high risk patients. vacA i1 allele was identified as an independent predictor of dysplasia (OR = 9.044; 95% CI: 1.11-73.33). Possession of s1/i1/cagA(+) strains was also identified as a predictor of intestinal metaplasia (OR = 3; 95% CI: 1.13-7.95), dysplasia (OR = 9.9; 95% CI: 1.23-80.86) and risk of GC (OR = 6.9; 95% CI: 2.5-18.66) as well as induction of anti-VacA sero-positivity (OR = 5.04; 95% CI: 1.8-13.6). Anti-VacA serology correctly detected 83.8% of s1/i1/cagA(+) strains carried by high-risk patients. CONCLUSIONS: The current study emphasizes the implication of vacA polymorphic structure, especially the s1/i1/cagA(+) genotype, in increasing the risk of GC by revealing their association with gastric pre-neoplastic changes and their reflection in VacA sero-positivity which encourages the application of noninvasive procedures in population screening.
Assuntos
Adenocarcinoma/microbiologia , Proteínas de Bactérias/genética , Infecções por Helicobacter/complicações , Helicobacter pylori/genética , Polimorfismo Genético , Neoplasias Gástricas/microbiologia , Adenocarcinoma/imunologia , Adenocarcinoma/patologia , Adulto , Anticorpos Antibacterianos/sangue , Proteínas de Bactérias/imunologia , Dispepsia/imunologia , Dispepsia/microbiologia , Feminino , Frequência do Gene , Genótipo , Infecções por Helicobacter/microbiologia , Helicobacter pylori/imunologia , Helicobacter pylori/metabolismo , Humanos , Masculino , Úlcera Péptica/imunologia , Úlcera Péptica/microbiologia , Fatores de Risco , Neoplasias Gástricas/imunologia , Neoplasias Gástricas/patologiaRESUMO
The Helicobacter pylori duodenal ulcer promoting (dupA) gene has been previously described as a risk marker for duodenal ulcer (DU) development and a protective factor against gastric cancer (GC). Recent studies which have assessed the application of dupA in the prediction of clinical outcomes have been controversial. In the current study, the association of dupA with the clinical outcomes and histopathological changes following H. pylori infection was evaluated in Iranian patients. A total of 157 H. pylori-infected patients with DU (n=30), gastric ulcer (n=23), gastritis (n=68) or GC (n=36) were assessed. The presence of jhp0917 and jhp0918 genes was determined by gene specific PCR. Gastric histopathological changes were recorded according to the updated Sydney system. Seventy-eight (49.7 %) and 71 (45.2 %) of the 157 tested strains, respectively, were positive and negative for both genes. The remaining 8 (5.09 %) of the 157 strains were jhp0917-positive/jhp0918-negative. Univariate analysis showed inverse associations between dupA and histological features including dysplasia as the penultimate stage of GC and lymphoid follicles as a consequence of relatively long-standing H. pylori-associated gastritis. The degrees of nucleotide sequence identity of Iranian strains to Colombian, Brazilian and Indian strains ranged from 86.1 to 100 % for the aligned regions of jhp0917, from 88 to 98.8 % for jhp0918 and from 93.4 to 99.5 % for the partial sequences of the dupA gene. Despite the fact that possession of the dupA gene showed no association with any disease category in our population as reported in several other countries, association of dupA-negative strains of H. pylori with pre-malignant lesions calls for additional studies to evaluate the role of this gene as a protective marker against GC.
Assuntos
Infecções por Helicobacter/microbiologia , Helicobacter pylori/metabolismo , Fatores de Virulência/metabolismo , Sequência de Bases , Úlcera Duodenal/microbiologia , Trato Gastrointestinal/microbiologia , Trato Gastrointestinal/patologia , Regulação Bacteriana da Expressão Gênica/fisiologia , Marcadores Genéticos , Helicobacter pylori/genética , Helicobacter pylori/patogenicidade , Humanos , Irã (Geográfico) , Dados de Sequência Molecular , Fatores de Risco , Neoplasias Gástricas/microbiologia , Virulência , Fatores de Virulência/genéticaRESUMO
BACKGROUND: Multiple etiologic factors are suspected to cause gastric cancer, the most important of which is infection with virulent types of Helicobacter pylori. MATERIALS AND METHODS: We have compared 102 gastric cancer patients with 122 non-ulcer, non-cancer dyspeptic patients. Gastric specimens were evaluated for H. pylori infection by tissue-based detection methods. Patient sera underwent antigen-specific ELISA and western blotting using a Helicoblot 2.1 kit and antibody responses to various H. pylori antigens were assessed. RESULTS: The absolute majority (97-100%) of both groups were H. pylori seropositive. Multivariate regression analysis demonstrated serum antibodies to the low molecular weight 35kDa protein to be protective and reduce the risk of gastric cancer by 60% (OR:0.4; 95%CI:0.1-0.9). Conversely, seroreactivity to the 89kDa (VacA) protein was significantly higher in gastric cancer patients (OR:2.7; 95%CI:1.0-7.1). There was a highly significant association (p<0.001) between seroreactivity to the 116kDa (CagA) and 89kDa (VacA) proteins, and double positive subjects were found at nearly five fold (OR:4.9; 95%CI:1.0-24.4) enhanced risk of gastric cancer as compared to double negative subjects. CONCLUSIONS: Seroreactivity to H. pylori low (35kDa) and high (116kDa/89kDa) molecular weight antigens were respectively revealed as protective and risk indicators for gastric cancer.