Effect of cagA status on the sensitivity of enzyme immunoassay in diagnosing Helicobacter pylori-infected children

Background. The aims of our study were twofold. First, we sought to evaluate in symptomatic children the influence of the Helicobacter pylori genotype on gastritis, abdominal pain, and circulating anti– H. pylori IgG antibodies (anti– H. pylori IgG) or pepsinogen A (PGA) and C (PGC). Additionally, we sought to assess anti– H. pylori IgG, PGA, and PGC patterns in a large cohort (N = 921) of asymptomatic children.
Materials and Methods. In 183 symptomatic children, H. pylori infection and the presence of gastritis were evaluated by histology. In a subgroup of 20 H. pylori –positive children, the H. pylori genotype was evaluated also by polymerase chain reaction. Nine hundred and twenty-one asymptomatic children, aged 11 to 14 years, were studied by anti– H. pylori IgG, PGA, and PGC serum determination.
Results. The infection was found in 33 of 183 symptomatic children; among the 20 H. pylori –positive children for which the H. pylori genotype was available, cag A was present or absent in equal percentages. H. pylori infection was associated with more severe gastritis and higher serum levels of anti– H. pylori IgG and PGC but not with abdominal pain. In infected children, higher levels of anti– H. pylori IgG and the presence of abdominal pain were associated with infections caused by cag A-positive strains. In the cohort of 921 asymptomatic children, raised levels of anti– H. pylori IgG, PGA, and PGC were found in approximately 5% of the cases.
Conclusions. Infection with cag A-positive H. pylori strains can be associated with increased frequency of reported abdominal pain and higher circulating levels of anti– H. pylori IgG. The serological assessment of H. pylori IgG using H. pylori antigens containing significant amounts of cagA protein may, therefore, underestimate the true prevalence of infection.     

Long-term follow up of Helicobacter pylori IgG serology after eradication and reinfection rate of H. pylori in South Korea

Background: Serology is widely used for epidemiologic research of Helicobacter pylori . However, there is limited information on the long-term follow up of H. pylori titers after eradication. In addition, it is presumed that the reinfection rate decreases as the H. pylori infection rate decreases. The aim of this study was to investigate the long-term follow up of H. pylori IgG, and to evaluate the reinfection rate of H. pylori in Korea.
Methods: Among 247 patients, who were enrolled during 2003–07, 185 patients with invasive H. pylori test positive received proton pump inhibitor-based triple therapy, and follow-up H. pylori testing, including histology, CLOtest, culture, and serology, were evaluated 2, 10, and 18 months after H. pylori eradication.
Results: The initial H. pylori IgG optical density (OD_450nm), 2.06, gradually decreased to 0.63 (67% reduction) at 18 months after H. pylori eradication. The seroreversion rate was 5, 10, and 45% at 2, 10, and 18 months after H. pylori eradication, respectively. The recrudescence of H. pylori was 3.49%, and the annual reinfection rate was 2.94% per year. H. pylori IgG titers abruptly increased in cases with recrudescence and reinfection, and correlated with the results of the invasive H. pylori tests.
Conclusion: The results of this study showed that H. pylori IgG serology could be used for the determination of reinfection of H. pylori, but not for the diagnosis of H. pylori eradication. The reinfection rate of H. pylori , in Korea, was found to be very low, 2.94% per year.     

A change of IL-2 and IL-4 production in patients with Helicobactor pylori infection

Hellcobacter pylori is the most common cause of gastroduodenal inflammation. However, the exact immune pathogenesis is not fully understood. To look for evidence of the immunological mechanism in H. pylori associated disease, we measured cytokine interleukin-2 (IL-2) and IL-4 levels produced by peripheral blood lymphocytes (PBL) and gastric biopsies in 20 subjects with or without H. pylori infection. H. pylori can stimulate IL-2 and IL-4 production from PBL in H. pylori negative as well as H. pylori positive individuals. The spontaneous IL-2 production by PBL and gastric biopsies was greater (p < 0.0025, <0.001)in H. pylori negative individuals than that in H. pylori infected patients. Increased IL-4 levels from PBL in H. pylori infected patients were found in the presence of H. pylori (p < 0.0025). An increased spontaneous production of IL-4 from gastric biopsies was also observed in H. pylori infected patients (p < 0.025). In conclusion, an enhanced type 2 cytokine production was observed in H. pylori infected patients, which may be responsible for H. pylori chronic infection.     

Decreased Prevalence of Helicobacter pylori Infection in Gastroesophageal Reflux Disease

Background.   An increased incidence of reflux esophagitis has been reported after eradication of H. pylori in patients with duodenal ulcer. To determine if H. pylori is associated with lower rates of esophagitis, we studied the prevalence of H. pylori infection in patients with and without reflux esophagitis and a subgroup of patients with concomitant peptic ulcer disease.
Methods.   Patients who underwent esophagogastroduodenoscopy and had diagnostic testing for H. pylori over a 30-month period were studied. H. pylori infection was determined by rapid urease testing, gastric histopathology, or serology. Reflux esophagitis was determined by endoscopic and/or histologic criteria.
Results.   Of 514 patients, 39.5% had H. pylori infection and 22.2% had reflux esophagitis. The prevalence of H. pylori infection in patients with reflux esophagitis was 30.7%, compared with 42.0% in patients without esophagitis ( p = 0.039). The odds ratio for esophagitis risk with H. pylori infection was 0.61 (95% CI, 0.39–0.95). Neither patient age nor gender affected H. pylori prevalence. In patients with duodenal ulcer, H. pylori was present in 36.4% of patients with esophagitis and in 69.2% of patients without esophagitis ( p = 0.018). The odds ratio for esophagitis with H. pylori infection in these patients was 0.25 (95% CI, 0.09–0.73).
Conclusions.   Our study demonstrates that H. pylori infection is significantly less prevalent in patients with reflux esophagitis and may protect against its development. In duodenal ulcer patients, this effect was more dramatic. Further study is required to confirm these findings and elucidate mechanisms underlying possible beneficial effects of H. pylori.     

Characterization of a culture method to recover Helicobacter pylori from the feces of infected patients

Background. Helicobacter pylori is difficult to culture from stool. Multiple efforts from multiple laboratories have been unsuccessful, and the optimal conditions to recover H. pylori from stool are still not known. Recovery of H. pylori from feces of infected individuals is important for the performance of molecular epidemiological investigations, especially in children, where their symptoms do not warrant endoscopy to recover the organism.
Methods. Fresh fecal specimens (noncathartic) were obtained from 19 known H. pylori –infected patients and were processed to recover the organism. Fresh fecal specimens (noncathartic) were also obtained from three known H. pylori –negative individuals (controls) to determine whether H. pylori could be isolated from stools seeded with known concentrations of the organism. Treatment of the fecal suspensions with cholestyramine, a basic anion exchange resin that binds bile acids, was used in an attempt to enhance recovery of H. pylori by sequestering bile acids that are inhibitory to H. pylori growth. H. pylori was identified based on colony morphology, cell morphology, Gram's stain, biochemical reactions, and polymerase chain reaction for two H. pylori genes.
Results. Among 19 patients, H. pylori was cultured at least once from 3 and three times from 2 (5 of 19). Feces that were seeded with H. pylori and obtained from three H. pylori –negative volunteer controls yielded positive recovery in all instances.
Conclusion. We have confirmed that it is possible to culture H. pylori from human stool, but the procedure for optimal recovery has still not been defined.     

Role of Helicobacter pylori Infection in the Treatment and Outcome of Chronic Urticaria

Introduction:  Chronic urticaria is thought to have numerous causative factors including a large variety of infectious conditions, food intake, and drugs. The impact of Helicobacter pylori infection has been studied with ambiguous results. The aim of this study was to investigate the course of chronic urticaria in H. pylori -positive patients undergoing eradication compared to H. pylori -negative urticaria patients.
Patients and Methods:  We included 74 urticaria patients with positive H. pylori breath test and 74 age- and sex-matched H. pylori -negative controls. All urticaria patients underwent an extensive diagnostic work-up to search for trigger foci. H. pylori -infected patients were submitted to eradication therapy. Mean follow-up time was 58 months.
Results:  Neither the prevalence of H. pylori nor the eradication therapy had an influence on the clinical course of chronic urticaria. In 81.1% of H. pylori -infected patients at least one additional infectious focus was found. Nevertheless, it could be shown that individuals that described any kind of symptom relief presented with higher serum IgE levels at diagnosis (198.1 vs 115.7 kU/L, p = .027) but this effect was independent of H. pylori infection.
Conclusions:  In conclusion there is no evidence that eradication of H. pylori improves the outcome in patients with chronic urticaria. The high rate of spontaneous remission and the coexisistance of multiple foci will always obscure the evaluation of any specific antimicrobial therapy.     

Prevalence of Helicobacter pylori Infection and Identification of Risk Factors in Rural and Urban Beijing, China

Background:  The prevalence of Helicobacter pylori is higher in developing countries such as China. The aim of this study was to investigate the prevalence of H. pylori in one rural and one urban region of Beijing, China.
Materials and Methods:  Healthy individuals in rural Pinggu and urban Haidian voluntarily participated in this study. The diagnosis of H. pylori infection was reached using the ¹³C-urea breath test. Associations between H. pylori and sex, age, living area (i.e. rural vs urban), education level, smoking, and alcohol consumption were evaluated.
Results:  Of the 1232 included subjects, 54.7% of tested individuals residing in Pinggu and 41.3% in Haidian were positive for H. pylori . In urban region, more individuals were negative for H. pylori (429 of 731), whereas in the rural region, more individuals were positive for H. pylori ( p <  .05). Univariate analysis identified geographic area and lower education and annual income as significant factors associated with H. pylori . Men in rural areas were more likely than women in rural areas to be infected, and both men and women in the rural area were more likely to be positive for H. pylori than men and women in the urban area (all p  < .05).
Conclusions:  H. pylori infection is common in both rural and urban regions of Beijing. Residing in a rural area, having a lower family income, and lower education level are significant risk factors associated with infection.     

Overexpression of YKL-40 Predicts Plaque Instability in Carotid Atherosclerosis with CagA-Positive Helicobacter Pylori Infection

Objectives

YKL-40 has been demonstrated to be related to atherosclerosis, but its role in predicting plaque status and the outcome of carotid atherosclerosis (CAS) caused by CagA-positive helicobacter pylori remains unclear. This study was aimed to investigate the role of YKL-40 in predicting the outcome of carotid atherosclerosis with CagA-positive Helicobacter pylori infection.

Methods

The serum concentrations of YKL-40, C-reaction protein in 310 patients undergoing color Duplex assessment of carotid atherosclerosis were recorded and divided into 3 groups according to the infectious statuses of helicobacter pylori. We also examined serum YKL-40, C-reaction protein and the plaque morphology in animal model of carotid atherosclerosis with different types of helicobacter pylori infection.

Results

Overexpression of YKL-40 was only found in carotid atherosclerosis group with CagA-positive helicobacter pylori infection; C-reaction protein failed to distinguish different infectious statuses of helicobacter pylori infection. In patients with CagA-positive helicobacter pylori infection, elevated YKL-40 expression was accompanied by more severe clinical symptoms. We also confirmed similar findings in rabbit model of carotid atherosclerosis with CagA-positive helicobacter pylori infection. We found that in 7 rabbits treated with anti-helicobacter pylori therapy, the serum YKL-40 level decreased and the plaque became more stable.

Conclusion

Our findings suggested that increased serum YKL-40 level indicates plaque instability and more severe clinical symptoms of carotid atherosclerosis with CagA-positive helicobacter pylori infection. Compared with C-reaction protein, YKL-40 seems to be a more specific predictor of plaque status and outcome of carotid atherosclerosis with CagA-positive helicobacter pylori infection.     

Salivary specific IgG is a sensitive indicator of the humoral immune response to Helicobacter pylori

Abstract In humans, salivary antibodies are secreted during humoral immune response. Helicobacter pylori infection is associated with systemic humoral immune response reflected by raised serum levels of specific IgG. The present study was aimed at exploring whether salivary concentrations of specific H. pylori IgG are a reliable indicator of H. pylori infection. Serum and salivary samples were obtained from 291 subjects attending the GI clinic and tested for H. pylori -specific IgG by a direct ELISA (94% sensitivity, 95% specificity for serum determinations) using a crude H. pylori sonicate as antigen. Data are given as optical density (mean±S.D.). Levels of salivary H. pylori IgG paralleled those of circulating specific IgG in the 291 subjects studied (0.981±0.431 vs. 0.777±0.682, respectively). A significant positive correlation was found between specific H. pylori IgG in sera and saliva samples (r = 0.981, P < 0.0001). An overall concordance between circulating and salivary H. pylori IgG was observed in 238 out of the 291 (81.7%) subjects. Salivary H. pylori IgG represent a sensitive marker of specific humoral immune response and they may substitute circulating H. pylori IgG measurement when sera samples are not available.     

Monocyte and Macrophage Killing of Helicobacter pylori: Relationship to Bacterial Virulence Factors

Background:  Helicobacter pylori infection is an important health problem, as it involves approximately 50% of the world's population, causes chronic inflammatory disease and increases the risk of gastric cancer development. H. pylori infection elicits a vigorous immune response, but this does not usually result in bacterial clearance. We have investigated whether the persistence of H. pylori in the host could be partly due to an inability of macrophages to kill this bacterium.
Materials and Methods:  Monocytes and macrophages isolated from the peripheral blood of normal human controls were infected in vitro with five H. pylori isolates. The isolates were characterized for known H. pylori virulence factors; vacuolating cytotoxin (VacA), the cag pathogenicity island ( cag PAI), urease, and catalase by Western blot and polymerase chain reaction analysis. The ability of primary human monocytes and macrophages to kill each of these H. pylori strains was then defined at various time points after cellular infection.
Results:  The five H. pylori strains showed contrasting patterns of the virulence factors. There were different rates of killing for the bacterial strains. Macrophages had less capacity than monocytes to kill three H. pylori strains. There appeared to be no correlation between the virulence factors studied and differential killing in monocytes.
Conclusions:  Primary human monocytes had a higher capacity to kill certain strains of H. pylori when compared to macrophages. The VacA, cag PAI, urease, and catalase virulence factors were not predictive of the capacity to avoid monocyte and macrophage killing, suggesting that other factors may be important in H. pylori intracellular pathogenicity.     

Construction of isogenic urease-negative mutants of Helicobacter pylori by allelic exchange.

Isogenic urease-negative mutants of Helicobacter pylori were constructed by allelic replacement. A region of cloned H. pylori DNA containing the structural urease genes (ureA and ureB) was disrupted by insertion of a mini-Tn3-Km transposon. Electrotransformation of H. pylori cells with kanamycin-ureB-disrupted derivative plasmids resulted in isolation of kanamycin-resistant H. pylori transformants. Competence for electrotransformation appeared to be restricted to certain wild-type H. pylori isolates; only 1 isolate (of 10 tested) was consistently transformed. Two of the kanamycin-resistant H. pylori transformants were further studied and shown to be urease negative. Southern hybridization analyses demonstrated that the urease-negative mutants had been constructed by allelic exchange involving simultaneous replacement of the ureB gene with the kanamycin-ureB-disrupted copy and loss of the vector. Immunoblot studies of whole-cell extracts of the isogenic ureB mutants with anti-H. pylori sera indicated the absence of a polypeptide with an apparent molecular mass of 61 kDa; thus, the mutants no longer synthesized the UreB product. Generation of stable, genetically engineered urease mutants of H. pylori will be useful for addressing the role of urease in the pathogenesis of H. pylori infection.     

Childhood Hygienic Practice and Family Education Status Determine the Prevalence of Helicobacter pylori Infection in Iran

Background: Management of Helicobacter pylori , a causative agent of gastrointestinal diseases is an important health problem in most countries. The main reasons include poorly defined epidemiological status and unrecognized mode of bacterial transmission. Our objective was to investigate the prevalence of H. pylori infection in a representative population of Iran and to evaluate possible risk factors for the H. pylori infection.
Materials and methods: In this cross-sectional study, 2561 healthy individuals aged 18–65 years (mean age, 35.5 years) were selected out of 12,100,000 inhabitants of Tehran province by cluster sampling. Infection with H. pylori was evaluated by detection of anti- H. pylori IgG antibody in serum. Sociodemographic status of each subject was determined by filling up a questionnaire.
Results: Prevalence of H. pylori infection was 69% and was correlated with increasing age. The highest infection rate (79.2%) was seen in individuals 46–55 years old. No association was detected between H. pylori positivity and gender. Low education of the study subjects; low father's and mother's education; poor tooth brushing habit; crowded families in childhood; and lack of household bath, hygienic drinking water, and swage disposal facility in childhood were determined as possible risk factors.
Conclusions: The rate of prevalence of H. pylori infection was higher than developed countries. Low socioeconomic status, poor sanitary indications, and crowded families in childhood were related to high prevalence of H. pylori infection in Iran. Accordingly, fecal–oral and oral–oral routes could be considered as the main pathways of transmission of H. pylori .     

Aneurysm and Helicobacter pylori relationship: the seropositivity of CagA, VacA and other antigens of Helicobacter pylori in abdominal and ascending aortic aneurysms

Helicobacter pylori is thought to be related to atherosclerosis and aneurysm development. We aimed to detect virulance factors of H. pylori and examine the potential etiopathogenetic relationship between aortic aneurysm and H. pylori, 58 abdominal aortic aneurysm (AAA) and 38 ascending aortic aneurysm (AsAA) cases and 57 Healty control group (HCG) were included. We investigated H. pylori IgG by ELISA and virulance factors by Western-Blot (WB) method. No difference was found between AAA (67.24%), AsAA (73.68%) and HCG (57.89%) for H. pylori IgG (p > 0.05). A significant difference was found between AsAA (78.95%) and HCG (57.89%) for H.pylori IgG (p < 0.05) by ELISA and a significant difference was found only between AsAA (100%) and HCG (37.5%) for H. pylori IgG in the 45-55 age group by WB. A statistically significant difference was found between AAA and AsAA for VacA and CagA + VacA and CagA + VacA + UreA antigens and also a significant difference was found between AsAA and HCG for CagA + UreA antigens (p < 0.05). Finally, we suggest that H. pylori VacA has a more important role than CagA in the development of two aneurysms especially in ruptured AAA. New extended studies detecting H. pylori DNA are needed to detect the aetiopathogenesis between aneurysm types and H. pylori.     

Prevalence and risk factors for Helicobacter pylori infection in Chinese populations

Background:  The prevalence of Helicobacter pylori is higher in developing countries. The aim of this study was to investigate the prevalence and risk factors of H. pylori infection in areas with high prevalence of gastric cancer in Jiangsu Province, China.
Methods:  A prospective epidemiologic survey of H. pylori infection was accomplished in a natural population of 1457 individuals in Xiangshui and Gaoyou counties, Jiangsu Province, China. Questionnaires and laboratory tests for H. pylori infection (¹³C-urea breath test and serum IgG antibodies to H. pylori ) were used and performed, respectively.
Result:  Among 1371 subjects who completed questionnaires and H. pylori detection, 851 (62%) were H. pylori positive. The prevalence reached a peak at the age of 30–40 years (67%). There was no sex difference. The annual family income level was shown to be positively correlated with the risk of H. pylori infection. The prevalence of H. pylori infection was also associated with family size, education level, and several diet-related factors, such as the number of times cooked rice and potatoes eaten per week, and a family history of stomach diseases. Compared to nonsymptomatic individuals, people with dyspeptic symptoms (nausea, vomiting, and belching) presented a low prevalence of H. pylori infection. No association between H. pylori prevalence and smoking or drinking was found. Using multivariate logistic regression analysis, annual family income and education level were the independent predictors for H. pylori infection.
Conclusion:  High prevalence of H. pylori infection was found in areas with a high risk of gastric cancer and was related to several risk factors. The underlying mechanisms need to be further investigated.     

Isotypic analysis of specific antibody response in serum, saliva, gastric and rectal homogenates of Helicobacter pylori-infected patients

Abstract The relationship between systemic and local humoral immune response to Helicobacter pylori is poorly understood. To further address this issue we measured, using ELISA, H. pylori -specific IgG and IgA antibodies in serum, saliva, gastric and rectal homogenates of H. pylori -infected patients. A total of 107 patients who underwent upper GI endoscopy and/or sigmoidoscopy were studied. The isotypic pattern of H. pylori -specific antibodies appeared to differ at the serum, salivary, gastric and rectal mucosa level. Serum H. pylori IgG titers were higher than those of the serum-specific IgA. On the contrary, in saliva samples. H. pylori IgA titers were higher than specific IgG titers. In gastric homogenates, specific IgG and IgA titers were similar. H. pylori -specific IgG were detectable in rectal homogenates but no or very low H. pylori -specific IgA were found in the same material. Furthermore, no difference was found in H. pylori IgG and IgA in serum, saliva and gastric homogenates between duodenal ulcer and non-ulcer dyspepsia patients. Data of the present study indicate that, in H. pylori -infected patients, the specific immune response is as follows: (1) it involves the secretory immune system; (2) it is paralleled by the specific salivary IgA; (3) it does not differentiate duodenal ulcer from non-ulcer dyspepsia patients; and (4) it does not take place in the large bowel.     

Guidelines for the Management of Helicobacter pylori Infection in Japan: 2009 Revised Edition

Background:  Over the past few years, the profile of Helicobacter pylori infection has changed in Japan. In particular, the relationship between H. pylori and gastric cancer has been demonstrated more clearly. Accordingly, the committee of the Japanese Society for Helicobacter Research has revised the guidelines for diagnosis and treatment of H. pylori infection in Japan.
Materials and Methods:  Four meetings of guidelines preparation committee were held from July 2007 to December 2008. In the new guidelines, recommendations for treatment have been classified into five grades according to the Minds Recommendation Grades, while the level of evidence has been classified into six grades. The Japanese national health insurance system was not taken into consideration when preparing these guidelines.
Results:  Helicobacter pylori eradication therapy achieved a Grade A recommendation, being useful for the treatment of gastric or duodenal ulcer, for the treatment and prevention of H. pylori -associated diseases such as gastric cancer, and for inhibiting the spread of H. pylori infection. Levels of evidence were determined for each disease associated with H. pylori infection. For the diagnosis of H. pylori infection, measurement of H. pylori antigen in the feces was added to the tests not requiring biopsy. One week of proton-pump inhibitor-based triple therapy (including amoxicillin and metronidazole) was recommended as second-line therapy after failure of first-line eradication therapy.
Conclusion:  The revised Japanese guidelines for H. pylori are based on scientific evidence and avoid the administrative restraints that applied to earlier versions .     

改良幽门螺杆菌抗原检测试剂盒 检测粪便幽门螺杆菌抗原的临床评价

目的评估改良幽门螺杆菌抗原检测试剂盒检测粪便幽门螺杆菌抗原(Helicobacter pylori stool antigen,HpSA)的准确性以及临床应用价值。方法采用随机、双盲、双验证和与~(13) C呼气试验(~(13) C-UBT)对比的方法,对门诊175例接受~(13) C-UBT检测的患者,采用最新研制出的一种改良幽门螺杆菌抗原检测试剂盒(胶体金法)检测粪便幽门螺杆菌抗原,以~(13) C-UBT检测结果为诊断H.pylori感染的"金标准",并将两者进行对比研究,所有检测结果均拍照存档,采用随机、双盲和双验证法,以期客观真实地评价改良幽门螺杆菌抗原检测试剂盒检测粪便幽门螺杆菌的效果。结果改良幽门螺杆菌抗原检测试剂盒检测HpSA敏感度为90.48%,特异度为90.00%,Youden指数为80.48%,Kappa值为0.799;HpSA检测ROC曲线下面积为0.902±0.027,与完全无诊断价值的机会线下面积0.50相比,差异有统计学意义(P=0.000);Spearman相关系数r=0.800,P=0.000。结论改良幽门螺杆菌抗原检测试剂盒能准确检测H.pylori感染,其操作简便,可作为非侵入性诊断H.pylori感染筛查以及流行病调查的一种方法,将来有望成为患者家庭自查幽门螺杆菌的一种方法。     

Helicobacter pylori and Non-malignant Diseases

In 2007 Helicobacter pylori research continued to deal with some controversies raised in the last decade. The main problems remain unsolved: peptic ulcer disease negative for H. pylori , synergism of H. pylori infection and aspirin and other nonsteroidal anti-inflammatory drugs or cyclooxygenase 2 specific inhibitors, the role of H. pylori eradication in uninvestigated and nonulcer dyspepsia, and the possible protective effect of H. pylori infection against gastroesophageal reflux disease and its complications such as Barrett's esophagus and adenocarcinoma. The incidence and prevalence of peptic ulcer disease as well as ulcer-related mortality are continuing to decline all over the world. The increasing consumption of anti-inflammatory and antisecretory drugs was not found to change the trend over the last period and therefore H. pylori was considered the key factor in causing ulcer-related mortality. Some progress has been achieved in understanding H. pylori -induced immunological processes, and attack mechanisms, as well as specific pathogenesis in uremic and cirrhotic patients. There is still a lot to learn about the bacterium and host factors related to H. pylori infection and its complications.     

Presence of Thrombin-Activatable Fibrinolysis Inhibitor in Helicobacter pylori-Associated Gastroduodenal Disease

Thrombin-activatable fibrinolysis inhibitor (TAFI) plays a role in the regulation of coagulation and inflammation. In addition to inhibiting the fibrinolytic system, TAFI may also regulate the bradykinin and complement systems. We hypothesized that TAFI also plays a role in defense mechanisms of the gastric mucosa during Helicobacter pylori infection. This study comprised 65 patients with gastroduodenal disorders: 41 patients with H. pylori infection, 13 without, and 11 patients with cured H. pylori infection. The gastric intramucosal concentrations of TAFI were measured by enzyme immunoassay. The gastric levels of TAFI and plasminogen activator inhibitor-1 were significantly increased in patients with H. pylori compared to those without infection or cured H. pylori . The presence of TAFI was detected in gastric mucosal epithelial cells. The concentration of TAFI was correlated with the degree of gastric mucosal atrophy, inflammation, and disease activity. These results show that TAFI is present in the gastric mucosa and that it may play a role in the pathogenesis of H. pylori infection-associated gastroduodenal disorders.