Clinical importance of Campylobacter pyloridis and associated serum IgG and IgA antibody responses in patients undergoing upper gastrointestinal endoscopy

British Society of Gastroenterology guidelines on the management of functional dyspepsia

Functional dyspepsia (FD) is a common disorder of gut-brain interaction, affecting approximately 7% of individuals in the community, with most patients managed in primary care. The last British Society of Gastroenterology (BSG) guideline for the management of dyspepsia was published in 1996. In the interim, substantial advances have been made in understanding the complex pathophysiology of FD, and there has been a considerable amount of new evidence published concerning its diagnosis and classification, with the advent of the Rome IV criteria, and management. The primary aim of this guideline, commissioned by the BSG, is to review and summarise the current evidence to inform and guide clinical practice, by providing a practical framework for evidence-based diagnosis and treatment of patients. The approach to investigating the patient presenting with dyspepsia is discussed, and efficacy of drugs in FD summarised based on evidence derived from a comprehensive search of the medical literature, which was used to inform an update of a series of pairwise and network meta-analyses. Specific recommendations have been made according to the Grading of Recommendations Assessment, Development and Evaluation system. These provide both the strength of the recommendations and the overall quality of evidence. Finally, in this guideline, we consider novel treatments that are in development, as well as highlighting areas of unmet need and priorities for future research.

Correlation of serology with morphological changes in gastric biopsy in Helicobacter pylori infection and evaluation of immunohistochemistry for H. pylori identification

BACKGROUND/AIM

Helicobacter pylori is implicated in various gastroduodenal diseases and many tests are available for its detection. The present study attempted to document the morphological changes in the gastric mucosa induced by H. pylori colonization and correlate them with the severity of the infection. The study also compared various diagnostic tests and evaluated the different staining methods used for H. pylori detection, especially immunohistochemical identification.

PATIENTS AND METHODS

One hundred and two patients with dyspepsia were included. Enzyme-linked immunosorbent assay (ELISA) for H. pylori-specific immunoglobulin G (IgG), immunoglobulin A (IgA), and immunoglobulin M (IgM) was used. Rapid urease test was performed on endoscopic biopsy and it was stained with hematoxylin and eosin (H and E), modified Giemsa, and immunohistochemical stains.

RESULTS

A significant correlation was found between the density of H. pylori and severity of gastritis. A significant correlation was observed between serology (especially when used in combination, IgG and IgA) and status of H. pylori. Immunohistochemical staining enhanced the diagnostic yield of H. pylori detection.

CONCLUSIONS

Immunohistochemistry (IHC) should be used judiciously, whereas simple and economical tests like modified Giemsa should be used routinely for the detection of H. pylori. Combined ELISA (IgG and IgA) should be preferred over single ELISA. Simultaneous morphological and serological detection of H. pylori is preferable as H. pylori may not be detected on morphology alone due to its patchy distribution in the stomach.

Role of transcription factor T-bet expression by CD4+ cells in gastritis due to Helicobacter pylori in mice

Gastritis due to Helicobacter pylori is induced by a Th1-mediated response that is CD4 cell and gamma interferon (IFN-gamma) dependent. T-bet is a transcription factor that directs differentiation of and IFN-gamma secretion by CD4+ Th1 T cells. The goal of this study was to use two mouse models to elucidate the role of T-bet in gastritis due to H. pylori. C57BL/6J mice, congenic T-bet knockout (KO) mutants, or congenic SCID (severe, combined immunodeficient) mutants were given live H. pylori by oral inoculation. SCID mice were given CD4+ splenocytes from C57BL/6J or T-bet KO mice by intraperitoneal injection. Twelve or 24 weeks after bacterial inoculation, C57BL/6J mice developed moderate gastritis but T-bet KO mice and SCID mice did not. In contrast, SCID recipients of either C57BL/6J T cells or T-bet KO T cells developed gastritis 4 or 8 weeks after adoptive transfer. In recipients of C57BL/6J CD4+ cells but not recipients of T-bet KO cells, gastritis was associated with a delayed-type hypersensitivity response to H. pylori antigen and elevated gastric and serum IFN-gamma, interleukin 6, and tumor necrosis factor alpha. In spite of the absence of IFN-gamma expression, indicating failure of Th1 differentiation, CD4+ T cells from T-bet KO mice induce gastritis in H. pylori-infected recipient SCID mice. This indicates that Th1-independent mechanisms can cause gastric inflammation and disease due to H. pylori.

Childhood peptic ulcer in the Ural area of Russia: clinical status and Helicobacter pylori-associated immune response

BACKGROUND

The relation of between Helicobacter pylori and the symptoms in children is still controversial. Determination of specific immunoglobulin (Ig) G antibodies to H. pylori may represent a useful test to screen the patients with acid peptic disease in childhood. The aim of this study was to investigate the spectrum of clinical symptoms, endoscopic and histologic lesions, and clinical value of serum IgG response to H. pylori in school-aged children residing in the Ural area of Russia for the identification of Helicobacter -related acid-peptic disease.

METHODS

During 1998, 129 pediatric outpatients (mean age, 12.1 +/- 2.3 years; age range, 10-15 years; 41 boys, 88 girls) were undergoing gastroduodenal endoscopy for evaluation of chronic abdominal pain. H. pylori colonization was determined by histology, urease test, and polymerase chain reaction. H. pylori IgG antibodies were found by using an enzyme-linked immunosorbent assay.

RESULTS

There was a high prevalence of H. pylori infection (80%) and peptic ulcers (24%) among the study group. Duodenal ulcers were detected in 31 of the children; all of them were H. pylori positive. Family history of peptic ulcers, nighttime pain associated with nocturnal awakening, fasting pain relieved by food, pain associated with meals, postprandial pain, bitter taste, and heartburn were the clinical signs that helped to distinguish the ulcer-positive children from the ulcer-negative H. pylori group. Duodenal ulcer patients had higher anti- H. pylori IgG titers compared with the levels of IgG antibodies in the infected children without ulcers ( P < 0.001). Peptic ulcer disease was a more common finding in the Ural ethnic group of Asians (Bashkirs) compared with the pediatric population of Russian origin.

CONCLUSIONS

These results provide further evidence for a causal relation between H. pylori -associated peptic ulcer disease in childhood and relevant clinical symptoms. High titers of anti- H. pylori IgG might serve as a useful noninvasive indicator of ulcer disease.

Effect of the treatment of Helicobacter pylori infection on gastric emptying and its influence on the glycaemic control in type 1 diabetes mellitus

Helicobacter pylori (Hp) infection plays a role in gastric emptying (GE) in type 1 diabetic patients and may have implications for glycaemic control. The aim of our study was to investigate this relationship. Gastric emptying was studied in 13 patients with type 1 diabetes and Hp infection. The Hp infection status was assessed by serology and urease breath test (UBT). In addition upper gastrointestinal endoscopy with gastric mucosal biopsy was performed to look for gastritis. A radionuclide-labeled solid meal was used to study GE before and after eradication therapy (amoxicillin, clarithromycin and omeprazole) for Hp infection. All patients were evaluated for autonomic and peripheral neuropathy and were asked for symptoms of gastrointestinal motor dysfunction. Blood glucose levels were determined before the meal and at 30,60,90 and 120 min after the start of the meal. Home blood glucose self-monitoring and HbA(1c) were performed to document glycaemic control during the study. Three months after treatment, five patients were free of Hp infection and were without gastritis (group I: no Hp infection, no gastritis); eight of the patients continued to have gastritis after treatment (group II) and of these eight patients, six had gastritis without Hp infection and two had gastritis plus persistent Hp infection. These last two patients were re-treated with eradication therapy. Patients with gastritis were re-evaluated 6 months after initial treatment; at which time four were now free of gastritis and were added to group I (n=9) while four continual to have gastritis although without Hp infection (group II, n=4). In group I, GE half-time showed an increase (30.6+/-10.3 min vs. 60.2+/-15.4 min; P<0.05) while no change (28.8+/-9.5 vs. 26.9+/-8.7 min; n.s.) was observed in group II. GE half-time was not altered by autonomic and peripheral neuropathy or blood glucose during solid meal test. HbA(1c) did not change significantly after treatment in either groups but the blood glucose levels were more stable in group I compared to group II. A delay in GE was observed with disappearance of gastritis associated to H. pylori infection after eradication treatment in patients with type 1 diabetes. This change in GE could help to stabilise the blood glucose levels in these patients treated with insulin before each meal.

H. pylori-negative duodenal ulcer prevalence and causes in 774 patients

The prevalence of H. pylori infection has been reported to be very high in duodenal ulcer (DU) disease, but the precise frequency and causes of H. pylori-negative DU are not well known. In some geographical regions, however, a relatively low prevalence of the infection has been described. Our aim was to study the frequency and causes of H. pylori-negative DU and to evaluate whether empirical H. pylori eradication therapy without confirmation of the infection is justified. In all 774 consecutive patients with an endoscopic diagnosis of DU were studied prospectively. Exclusion criteria were associated diseases and previous gastric surgery. The use of NSAIDs, antibiotics (during the last month), and proton pump inhibitors (during the last month) was evaluated by means of a specific questionnaire. At endoscopy, two biopsies from both antrum and corpus were obtained in all 774 patients for histologic study (H&E stain). One sample from the antrum for rapid urease test, one sample each from the antrum and corpus for culture, and two duodenal biopsies for histologic study were also obtained in the first 307 patients. A [13C] urea breath test was carried out in the remaining 467 patients. Patients were considered infected if any of the diagnostic tests were positive and noninfected when all tests performed were negative. Age (mean +/- SD) was 46+/-12 years, 70% were males. NSAID, antibiotic, and proton pump inhibitor use was described, respectively, in 8.9%, 5.8%, and 6.3% of the cases. H. pylori infection was demonstrated, overall, in 95.3% (95% CI: 93.6-96.6%) of the patients. H. pylori prevalence increased up to 99.1% (98.1-99.6%) if patients taking NSAIDs and/or antibiotics were excluded. Among the 36 H. pylori-negative patients, 20 (55%) were taking NSAIDs, 9 (25%) were taking antibiotics, and 1 (3%) both of them. Therefore, in only 6/774 patients (0.8%) could DU disease be considered truly "idiopathic." Differences were demonstrated between H. pylori-positive and -negative patients (univariate study; chi2) with regard to NSAID intake (7% vs 58%; P < 0.0001) and previous antibiotic use (5% vs 28%; P < 0.0001). In the multivariate analysis (logistic regression), NSAID use (OR: 0.06; CI: 0.03-0.13; P < 0.001) and antibiotic use (OR: 0.23; CI: 0.09-0.59; P < 0.01) were the only variables that correlated with H. pylori infection. The most important factors associated with H. pylori-negative DU are NSAIDs and prior antibiotic use, and if these agents are excluded, the prevalence of infection in our area is as high as 99%. Therefore, in DU patients not taking NSAIDs and living in areas where previous studies have shown the prevalence of the infection in DU disease to be very close to 100%, empirical H. pylori eradication therapy without confirmation of the infection may be justified.

Improvement in lipid and haemostasis patterns after Helicobacter pylori infection eradication in type 1 diabetic patients

Helicobacter pylori has been implicated in the cardiovascular risk of diabetic patients. The aim of our study was to investigate whether the Helicobacter pylori infection plays a role in the lipid and haemostasis patterns of type 1 diabetic patients. Twenty nine patients with type 1 diabetes mellitus and H. pylori infection were enrolled (Chlamydia pneumoniae negative). The H. pylori infection status was assessed by serology and urease breath test. In all patients levels of total cholesterol, triglyceride, HDL cholesterol, LDL cholesterol, lipoprotein (a) (Lpa) C reactive protein (CRP), fibrinogen, thrombin/antithrombin III complex (TAT), plasminogen activator inhibitor type 1(PAI-1), tissue plasminogen activator (t-PA) and von Willebrand antigen were measured. All patients were evaluated before and after H. pylori eradicating treatment with amoxicillin, clarithromycin and omeprazole. Twenty two patients were eradicated and seven remained infected. In H. pylori eradicated patients, HDL cholesterol increased (59.7+/-18.9 mg/dl vs 65.2+/-15. 9 mg/dl, P << 0.05), after treatment. After H. pylori eradication, the levels of CRP and TAT decreased (48+/-0.7 ng/l vs 3.3+/-0.4 ng/l;P << 0.05), (27.7+/-44.7 microg/ml vs 2.1+/-1.4 microg/ml, P << 0.05), respectively. The decrease in TAT was higher in the group of H. pylori (+) patients with higher levels of TAT (TAT >> 20 ng/ml, 92.8+/-41.6 ng/ml vs 1.9+/-2.0 ng/ml, P << 0.005; TAT 4Eth 20 ng/ml; 10.1+/-5.2 ng/ml vs 2.2+/-0.6 ng/ml, P << 0.05). These changes did not occur in patients without H. pylori eradication. Eradication of H. pylori infection in type 1 diabetic patients modifies some parameters of lipid and haemostasis patterns, (increase of HDL-cholesterol, reduction of Lpa and decrease of CRP and TAT) and so contributes to improvement of cardiovascular risk factors in these patients.

Gastric inflammation is enhanced in children with CagA-positive Helicobacter pylori infection

BACKGROUND

Helicobacter pylori infection is likely to be acquired at an early age. The factors leading to active inflammation in childhood, however, are largely unknown.

SUBJECTS AND METHODS

We determined the CagA status, the best characterized virulence factor of H. pylori, and serum antibodies of IgG and IgA classes to H. pylori in 39 infected children.

RESULTS

Mononuclear cell infiltration in the antrum but not in the gastric body was more intense in CagA-positive children than in CagA-negative children. The degree of polymorphonuclear cell infiltration on the other hand was independent of the CagA status. The antibody titers of IgG and IgA classes to H. pylori were higher in CagA-positive than in CagA-negative infections (P<0.001 and P<0.01, respectively). IgG antibody titers to H. pylori correlated directly with the density of mononuclear and polymorphonuclear cell infiltration in the gastric antrum but not in the gastric body.

CONCLUSION

H. pylori-infected children with CagA antibodies seem to have a more severe inflammation in the gastric antrum than CagA-negative children as shown by an increase in the density of antral mononuclear cells. A finding of higher serum antibody titers to H. pylori in CagA-positive children may be related to this enhancement of inflammation.

Serology and urea breath test in the diagnosis of H. pylori infection

Helicobacter pylori is a chronic infection that has the potential for causing and initiating serious gastric disease. Specific treatment can be successful in eradication of the infection but is currently complex which hampers essential patient compliance. Therefore, the accurate detection of H. pylori and, importantly, the post-treatment check for cure is vital in the effective management of this infection. This is especially true in cases of asymptomatic individuals. Serology is now a simple ELISA with a high degree of accuracy and has been shown to be useful as a screening tool prior to endoscopy in selected cases. The urea breath test, either using C13 or C14, is a sensitive test easily applied and is the test of choice for post-treatment check for cure. It is also the gold standard for the validation of serology in different populations.

Helicobacter pylori infection is markedly increased in patients with autoimmune atrophic thyroiditis

Infection by viral or bacterial pathogens has been suspected in playing a role in the development of autoimmune thyroid disease. Because Helicobacter pylori might be involved in the development of nongastrointestinal conditions such as rosacea, ischemic heart disease, and diabetes mellitus, we evaluated the prevalence of H. pylori infection in patients with autoimmune thyroid disease. Fifty-nine patients with autoimmune thyroid disease were included: autoimmune atrophic thyroiditis (n=21), Hashimoto's thyroiditis (n=18), and Graves' disease (n=20). Twenty patients with nontoxic multinodular goiter served as controls for nonautoimmune thyroid disease, and 11 patients with Addison's disease served as controls for nonthyroid endocrine autoimmune disease. The levels of anti-H. pylori immunoglobulin G (IgG) were determined, and a radiolabeled urea breath test were performed. The prevalence of H. pylori infection was markedly increased in the patients with autoimmune atrophic thyroiditis (85.7%), compared with the controls with nontoxic multinodular goiter (40%) and Addison's disease (45.4%). Infection by H. pylori resulted in increased levels of gastrin, pepsinogen I, and pepsinogen II in the H. pylori-positive groups, compared with the H. pylori-negative groups. A positive linear regression was found between the levels of microsomal autoantibodies and those of anti-H. pylori IgG in patients with autoimmune atrophic thyroiditis (n=21; r=0.79; p < 0.01). Finally, and although the overall prevalence of H. pylori infection was not increased, the anti-H. pylori IgG levels and the results from the breath test were higher in the patients with Graves' disease and Hashimoto's thyroiditis patients than in the controls. Clearly, the prevalence of H. pylori infection is increased in autoimmune atrophic thyroiditis and results in abnormalities of gastric secretory function. The strong relation between the levels of anti-H. pylori IgG and the levels of microsomal antibodies suggests that H. pylori antigens might be involved in the development of autoimmune atrophic thyroiditis or that autoimmune function in autoimmune atrophic thyroiditis may increase the likelihood of H. pylori infection.

Helicobacter pylori infection with parietal cell antibodies in children and adolescents with insulin dependent diabetes mellitus

One hundred and seventy-seven patients with insulin dependent diabetes mellitus (IDDM) diagnosed at the pediatric age were investigated for the presence of gastric parietal cell autoantibodies (PCA). The objective was to evaluate the prevalence of PCA seropositivity and to know whether Helicobacter pylori could be a reason for a higher presence of PCA in IDDM children and adolescents. Twelve of 177 patients (6.77%; confidence interval: 3.1-10.3) had detectable PCA. Gastric pathology was studied in eight of these patients and in seven patients without PCA. Diagnosis of H. pylori infection was made on antral biopsies. None of the patients had an atrophic gastritis. Six of the eight patients with PCA had gastric mucosa colonization by H. pylori and/or chronic gastritis. According to these results, we suggest that H. pylori can be the cause of the presence of PCA positive results in diabetic children and adolescents, and diabetic patients with detectable PCA should be screened for H. pylori.

Evaluation of experimental therapeutics in a new mouse model of Helicobacter felis utilizing 16S rRNA polymerase chain reaction for detection

BACKGROUND

A new mouse model of Helicobacter felis infection, which mimics the human infection observed with H. pylori, has recently been developed utilizing polymerase chain reaction (PCR) based on the 16S rRNA gene sequence for detection of infection.

METHODS

We tested several therapeutic regimens in this model, including some currently utilized in the clinic and some shown ineffective in the clinic.

RESULTS

The therapeutic results obtained by PCR with this model are consistent with results observed in the published human H. pylori clinical trials and also with results obtained in another H. felis mouse model utilizing culture and histology.

CONCLUSIONS

These results support further use of this new model in screening for new therapeutic regimens for the management of Helicobacter disease.

PCR detection of colonization by Helicobacter pylori in conventional, euthymic mice based on the 16S ribosomal gene sequence

Many animal models of Helicobacter infection have been described, including infection in rhesus monkeys, ferrets, gnotobiotic piglets, and mice. These animal models utilize a combination of detection methods, including culture, urease testing, and histopathology, all of which may be unreliable, insensitive, or labor-intensive. Development of new animal models of Helicobacter pylori requires new methods of detection with increased sensitivity and specificity. We have developed sensitive and specific PCR primers based on the 16S ribosomal gene sequence of H. pylori. The primers detected single-copy 16S DNA representing 0.2 cell of pure H. pylori (2 cells in the presence of mouse stomach mucosal DNA) and did not cross-react with closely related bacteria. We were able to detect colonization by H. pylori in conventional, euthymic, outbred mice up to 4 weeks postinoculation with a high percentage of isolates tested. One isolate of H. pylori was detected by PCR in 100% of the mice at 6 months and 60% of the mice 1 year after inoculation. Approximately 10(3) to 10(4) H. pylori cells per stomach were detected by utilizing this PCR methodology semiquantitatively. These primers and PCR methodology have facilitated detection of H. pylori colonization in conventional, euthymic mice, colonization which may not have been detectable by other methods.

Prevalence of Helicobacter pylori infection in infants and family contacts in a poor Bangladesh community

Although H. pylori is well established as an etiological agent of type B gastritis and a predisposing factor for peptic ulcer, knowledge about its transmission is unclear. In this study we examined the prevalence of H. pylori infection in the family members of index infants infected with this organism as indicated by positive [13C]-urea breath test (UBT). We performed UBT among family members of 15 predominantly breastfed infants, eight with and seven without H. pylori infection. Infection rates were 82% and 91% in family contacts of the infected and noninfected infants respectively, the average infection rate being 85%, which is rated to be high. There was no difference in infection rates among the parents of the infected and noninfected infants. Fifty percent and 70% families belonging to infected and noninfected infants, respectively, were found to have all members infected with H. pylori. No evidence of sex predilection of infection was found. We conclude that in communities with high prevalence of H. pylori infection, there is almost an equal infection rate among the family contacts of infected and noninfected infants, suggesting that environmental factors may be more important than intrafamilial transmission.

Helicobacter pylori expresses a complex surface carbohydrate, Lewis X

Monoclonal antibodies (MAbs) specific for Lewis X (Lex) reacted with whole cells of Helicobacter pylori NCTC11637, UA799, UA802, UA825, UA861, UA1182, and UA1206 in immunoelectron microscopy and enzyme-linked immunosorbent assay (ELISA) experiments. These MAbs have documented specificity to Lex, whereas MAbs for Lea and Leb were negative in both immunoelectron microscopy and ELISA. H. pylori coccoid forms also reacted with the MAbs, whereas the flagellum lacking the sheath showed no reactivity. The Lex structures were associated with membrane fractions in the ELISA experiments, and silver-stained sodium dodecyl sulfate-polyacrylamide gels confirmed the presence of lipopolysaccharides which reacted with the MAbs in immunoblots. Serum from an H. pylori-infected individual contained immunoglobulins which blocked the binding of the Lex MAbs, indicating that part of the host immune response to H. pylori is to the Lex structure. The ability of this gastric pathogen to mimic an oncofetal antigen (self) could explain the down regulation of anti-H. pylori T-cell response seen in H. pylori-infected individuals.

Seroepizootiology of Helicobacter pylori gastric infection in nonhuman primates housed in social environments

We determined the seroepizootiology of Helicobacter pylori infection in rhesus monkeys. Plasma was obtained from 196 animals (age range, 1 to 22 years) that were housed in social environments, either in indoor gang cages, in outdoor corrals, or in free-ranging forested conditions. Plasma immunoglobulin G levels were determined with a specific enzyme-linked immunosorbent assay, and the cutoff immunoglobulin G value for H. pylori seropositivity was determined from a study of 25 monkeys whose infection status was assessed by light microscopy and culture. One-year-old animals of both genders in all housing conditions had the lowest rate of positivity (60% in monkeys 1 year old versus 81% in monkeys 2 to 10 years old, P = 0.026). In addition, females tended to have higher rates of positivity than males. Seroconversion during a 1-year observation period occurred in 7 (28%) of 25 seronegative animals. Seroreversion occurred in 3 (4%) of the 78 positive animals; all 3 of these animals had received antimicrobial agents during the year. These observations demonstrate that the epizootiology of H. pylori infection in rhesus monkeys may serve as a model for human infection.

Recombinant antigens prepared from the urease subunits of Helicobacter spp.: evidence of protection in a mouse model of gastric infection

Urease is an important virulence factor for gastric Helicobacter spp. To elucidate the efficacy of individual urease subunits to act as mucosal immunogens, the genes encoding the respective urease subunits (UreA and UreB) of Helicobacter pylori and Helicobacter felis were cloned in an expression vector (pMAL) and expressed in Escherichia coli cells as translational fusion proteins. The recombinant UreA and UreB proteins were purified by affinity and anion-exchange chromatography techniques and had predicted molecular masses of approximately 68 and 103 kDa, respectively. Western blotting (immunoblotting) studies indicated that the urease components of the fusion proteins were strongly immunogenic and were specifically recognized by polyclonal rabbit anti-Helicobacter sp. sera. The fusion proteins (50 micrograms) were used, in combination with a mucosal adjuvant (cholera toxin), to orogastrically immunize mice against H. felis infection. Gastric tissues from H. felis-challenged mice were assessed by the biopsy urease test and by histology. In mice immunized with recombinant H. felis UreB, 60% of animals (n = 7) were histologically negative for H. felis bacteria after challenge at 17 weeks. This compared with 25% (n = 8) for mice immunized with the heterologous H. pylori UreB antigen. Neither the homologous nor the heterologous UreA subunit elicited protective responses against H. felis infection in mice. The study demonstrated that a recombinant subunit antigen could induce an immunoprotective response against gastric Helicobacter infection.

Natural gastric infection with Helicobacter pylori in monkeys: a model for spiral bacteria infection in humans

BACKGROUND/AIMS

There is no generally accepted model for Helicobacter pylori infection in humans. The aim of this study was to examine the natural history and effect of treatment in rhesus monkeys and sequentially define the immune response to H. pylori in relation to treatment.

METHODS

Infection and gastritis were graded blindly by histological analysis and culture of biopsy specimens harvested during gastroduodenoscopies in 26 anesthetized colony-bred monkeys. Plasma H. pylori-specific immunoglobulin (Ig) G levels were determined by enzyme-linked immunosorbent assay.

RESULTS

H. pylori and Gastrospirilum hominis-like organisms were present in 13 and 9 monkeys, respectively; 3 animals harbored both organisms, whereas 4 monkeys were not infected. Gastritis score was < or = 1.5 in animals uninfected or infected only with G. hominis-like organisms and > or = 2.0 in all H. pylori-infected animals. IgG ratios were > or = 0.5 in 12 of 13 H. pylori-infected animals and in 2 of 13 H. pylori-negative animals (P < 0.001). One monkey became infected with H. pylori during the observation period, with concurrent increase of gastritis and plasma IgG levels. In untreated animals, infection, gastritis, and plasma IgG levels remained unchanged over 7-15 months. Triple therapy eradicated H. pylori at 6 months in 4 of 6 animals while suppressing gastritis and plasma IgG levels.

CONCLUSIONS

Rhesus monkeys harboring H. pylori are persistently infected and have gastritis and elevated specific IgG levels, all of which may respond to appropriate therapy, whereas G. hominis infection is associated with little inflammation.

Helicobacter pylori infection in north-eastern peninsular Malaysia. Evidence for an unusually low prevalence

The prevalence of Helicobacter pylori infection was determined in peptic ulcer patients, in non-ulcer dyspepsia (NUD) patients, and in the general adult population. The H. pylori infection rate ascertained by microbiologic examination of multiple gastric antral biopsy specimens was 50% (17 of 34) in duodenal ulcer (DU), 5% (1 of 22) in gastric ulcer, and 9% (15 of 159) in NUD patients. A seroepidemiologic survey showed a prevalence of only 4.2% among 496 blood donors and 4.8% among 921 subjects who attended health screening clinics. H. pylori infection is relatively uncommon and does not appear to be the predominant factor in the pathogenesis of peptic ulcer disease in the area. The incidence of peptic ulcer perforations in the area in 1991-92 was 1.5 per 100,000 person-years, reflecting a relatively low frequency of peptic ulcers, which might be due to the low prevalence of H. pylori infection in the population.

Relation between IgG and IgA antibody titres against Helicobacter pylori in serum and severity of gastritis in asymptomatic subjects

AIMS

To investigate whether the absorbance index of IgG and IgA antibodies against Helicobacter pylori is related to a semiquantitative assessment of the density of H pylori colonisation in gastric biopsy specimens and to the severity of gastritis.

METHODS

The grade of gastritis was scored separately for antral and fundic mucosa using three different classifications. Serum IgA and IgG antibodies against H pylori were measured by ELISA. The density of gastric H pylori colonisation was graded semiquantitatively from 0 to 3.

RESULTS

Among 48 healthy volunteers studied, 17 were found to have gastritis according to Whitehead's criteria. H pylori was present in the biopsy specimens of 14 of 17 subjects with gastritis. The IgG H pylori antibody absorbance index was significantly (p < 0.05) correlated not only with the density of antral H pylori colonisation, but also with the degree of gastritis of the antrum, as assessed by the Whitehead score, activity, and the Sydney system (p < 0.05). The IgA H pylori antibody absorbance index was significantly correlated with the Whitehead score and Sydney system, but not with the activity score of the antrum or with the density of antral gastric H pylori infection. There were no significant correlations between the IgG H pylori antibody absorbance index and the gastritis scores of the fundus mucosa and the density of H pylori infection of the gastric body. The IgA H pylori antibody absorbance index was only significantly (p < 0.05) correlated with the density of H pylori colonisation and the Sydney system gastritis score of the corpus.

CONCLUSIONS

The serological absorbance index of IgG antibodies against H pylori is related to the severity of antral gastritis and the density of antral H pylori colonisation. Thus a high absorbance index of IgG antibodies against H pylori points to severe antral gastritis and dense H pylori colonisation of the antrum.

Assessment of four rapid urease test systems for detection of Helicobacter pylori in gastric biopsy specimens

An in vitro experiment and an in vivo clinical trial were both performed in order to assess the efficacy of four biopsy urease test systems, including one commercial kit, Temmler CUT test (Temmler Pharma, Marburg, Germany), for the rapid detection of Helicobacter pylori. We first evaluated four rapid urease test systems by inoculating bacterial suspensions of different concentrations into urea-containing media and observing the color change at room temperature. We found that the CUT test was superior in vitro to the other three urease test systems. As was expected, the lower the concentration of the inoculum, the slower was the color change and the fewer were the positive results noted. The minimal concentration of H. pylori for a positive urease test at 24 h was 1000-10,000 colony-forming units/ml in 1 drop of bacterial suspension inoculated. We then evaluated four biopsy urease test systems for the rapid diagnosis of H. pylori infection in antral and fundal mucosa biopsy specimens of 37 patients undergoing upper gastrointestinal endoscopy. All four test systems were 100% specific when compared with culture. In 69 culture-positive biopsy specimens, the CUT test was not only more sensitive (72%) than the other three systems (42%, 51%, and 45%, respectively), but also gave the fastest reaction by detecting more culture-positive biopsy specimens after 3 h of incubation at room temperature. The differences were statistically significant.

Humoral immune response against Helicobacter pylori as determined by immunoblot

An immunoblot method has been evaluated to diagnose Helicobacter pylori infection serologically by comparing 69 serum specimens from patients with a positive Gram stain and/or culture result and a positive urease test on biopsy material, as well as 51 serum specimens from patients with at least 4 negative urease tests, and negative microscopy and culture results. Sensitivity and specificity was found to be 100%. Recognition of the cross-reacting flagellin (66 kDa), flagellar sheath protein (51 kDa), and a 14 kDa protein are not a criterion for a current H. pylori infection. On the other hand, any combination of at least two of the 180, 120, 90, 75, 67, 29.5 and 19 kDa bands were diagnostic of infection. Three H. pylori strains, which were compared with both gel electrophoretic analyses and immunoblot reactivity, exhibited in part strong qualitative and quantitative differences that particularly affect the 120 kDa pathogenic factor, the large urease subunit and other proteins especially in the molecular mass range from 50 to 67 kDa. IgG immunoblot patterns showed that the choice of H. pylori strain, as well as a reproducible and standardizable antigen preparation, is of great importance for the reliability of serodiagnostic tests. The immunoblot method was found to be a valuable tool for the semi-quantitative confirmation of results achieved with other serological methods as well as optimization and quality control of the antigens used for serodiagnostic purposes.

Gastric cancer and Helicobacter pylori infection

Gastric adenocarcinoma can be divided into two histopathological types: intestinal and diffuse. In addition to the role of environmental factors, an association between gastric cancer and Helicobacter pylori has been suggested. A retrospective study was therefore carried out among 46 patients who had gastric cancer. As a control group, 40 patients with non-malignant disorders were selected (11 patients with peptic ulcer, 12 with chronic superficial gastritis, 17 with chronic atrophic gastritis). Twenty-six cancers were classified as intestinal type and 20 as diffuse type. H. pylori was found in 23 (88 per cent) of the intestinal type and 11 (55 per cent) of the diffuse type (P < 0.05). Patients with the intestinal-type gastric cancer had a higher prevalence of H. pylori infection than those with gastric ulcer (55 per cent) and chronic superficial gastritis (50 per cent) (P < 0.05). These findings suggest that there is a possible association between the intestinal type of gastric cancer and H. pylori infection.

Serodiagnosis of Helicobacter pylori infections with an enzyme immunoassay using the chromatographically purified 120 kilodalton protein

A membrane-associated 120 kDa protein of Helicobacter pylori with known species-specificity was isolated and used in an enzyme immunoassay (EIA) for the detection of Helicobacter pylori-specific IgG antibodies in patient sera. The EIA was compared with two other methods used for serodiagnosis of Helicobacter pylori infections: an EIA using sonicated whole Helicobacter pylori cell antigen and Western immunoblot. In a prospective study 127 unselected patients (76 patients with antrum gastritis, 51 patients without gastritis) who underwent gastroscopy were studied histologically and serologically. The EIA using the purified 120 kDa protein had the highest specificity (92%) compared with the EIA using a whole cell sonicate of a single Helicobacter pylori strain as antigen (60.7%) and the immunoblot (90.2%). The sensitivity was 96%, 100% and 92%, respectively. Sera of three control patients reacted strongly in all three methods, indicating possible Helicobacter pylori infection with negative histological findings. The EIA using the 120 kDa protein as antigen was shown to be a specific and sensitive technique for the serodiagnosis of Helicobacter pylori infections.

Serodiagnosis of Helicobacter pylori-associated gastritis with a monoclonal antibody competitive enzyme-linked immunosorbent assay

Forty-nine monoclonal antibodies against Helicobacter pylori were screened to investigate their capacity to be used in enzyme-linked immunosorbent assay (ELISA) competitive systems for the serodiagnosis of Helicobacter pylori infection. On the basis of the inhibition pattern showed by the sera of five infected patients, the antibodies were subdivided into five groups. The immunoblotting analysis showed that the antibodies recognized a total of nine different antigenic determinants. In a study of the reaction of the antibodies with 12 isolates of H. pylori a total of 9 antigenic profiles were identified. Two monoclonal antibodies, HpN44 and HpN45, which recognized a 64-kD protein, were inhibited by all 5 positive sera. Antibody HpN45 was labeled with horseradish peroxidase, and the competitive ELISA was compared with an ordinary indirect ELISA in a study of 102 patients undergoing gastroscopy. Seventy-three patients proved to be infected by H. pylori according to urease or histologic tests. The sensitivity and specificity were 90.4% and 89.6%, respectively, for the indirect ELISA and 100% and 89.6% for the HpN45 competitive assay. The three patients who were 'false seropositive' with both serologic tests had atrophic gastritis. The high diagnostic performance and simplicity of the HpN45 monoclonal competitive ELISA make it suitable for routine serodiagnosis of H. pylori infection.

Intestinal metaplasia and Helicobacter pylori: an endoscopic bioptic study of the gastric antrum

To study the relationship between intestinal metaplasia and Helicobacter pylori infection, 2274 gastroscopic antral biopsies taken from 533 patients were examined. Overall, intestinal metaplasia was found in 135 patients (25.3%) and H pylori in 289 patients (54.2%). The prevalence of intestinal metaplasia and H pylori was age related, being more common in patients greater than or equal to 50 years compared with patients less than 50 years (intestinal metaplasia, p less than 0.001 and H pylori, p less than 0.05). Intestinal metaplasia was found more often in H pylori positive patients compared with H pylori negative patients (33.9% v 15.2%, p less than 0.001). The mean age of intestinal metaplasia positive patients who were also H pylori positive was 64 (13.3) years, whereas the mean age of intestinal metaplasia positive patients who were H pylori negative was 72 (14.7) years (p less than 0.005). The extent of intestinal metaplasia was not statistically different in the latter two groups. Although our data do not prove a causal relationship between H pylori infection and the histogenesis of intestinal metaplasia it is suggested that H pylori infection is an important factor in the development of intestinal metaplasia, which is generally recognised as a precursor lesion of intestinal type gastric carcinoma.

Is Helicobacter pylori a cause of duodenal ulcer? A methodologic critique of current evidence

INTRODUCTION

Helicobacter pylori (HP) in the gastric antrum has been strongly associated with both duodenal ulcer (DU) and chronic active gastritis (CAG). The relationship between HP and DU has been interpreted as causal by many observers. An alternate hypothesis is that HP coincidently colonizes CAG, which is independently associated with DU by some yet-unknown mechanism.

PURPOSE

To assess the extent to which a causal relationship between HP and DU has been demonstrated, we performed a methodologic critique of published clinical studies. We carried out a literature search to identify clinical studies that included at least 25 subjects. Of the eight studies we identified, six used a cross-sectional design and two used a prospective cohort design. We applied methodologic criteria to assess causation: strength of association, biologic gradient, temporality, and experiment.

METHODS

A strong association between HP and DU was demonstrated in all eight studies. Biologic gradient and temporality were not assessed in any study. In the two experimental studies of therapy, loss of antral HP was associated with a decreased rate of DU relapse; however, we did not interpret this as sufficient to support causality because the effect may have been due to a direct mucosal action rather than eradication of HP.

CONCLUSION

We conclude that published evidence does not establish HP as a cause of DU. One approach to address causality would be an observational cohort study of ulcer relapse to assess the temporal relationships between HP, CAG, and DU.

Helicobacter pylori: a Jordanian study

The prevalence of Helicobacter pylori in patients with upper gastrointestinal symptoms in the north of Jordan was studied prospectively. The occurrence of H. pylori was documented histologically and bacteriologically in 169 patients attending endoscopy for upper gastrointestinal symptoms. Our results showed that H. pylori was present in 70% of patients with acute gastritis, 73% of patients with chronic gastritis, 68% of patients with acute on chronic gastritis, 83% of patients with duodenal ulceration, 75% of the patients with gastric ulceration, 64% of patients with no pathology, and 68% of patients regardless of the pathology found. There was a sharp rise in the prevalence of H. pylori with age, up to the age of 40 years with an annual increase in the prevalence of 2%. This study shows that the prevalence of H. pylori in Jordan is similar to that seen in other developing countries with infections occurring at a lower age and with the annual infection rate being double that seen in developed countries.

Serum immune response to Helicobacter pylori in children: epidemiologic and clinical applications

Antibody responses to Helicobacter pylori were measured by a solid-phase whole-cell enzyme-linked immunosorbent assay in 150 children and adolescents; in 47 consecutive children undergoing upper gastrointestinal endoscopy, including 17 with H. pylori infection before and after antimicrobial treatment; and in 46 family members of the infected children. Abnormal levels of either IgG or IgA were found in 6% of the 150 children. In the latter group the prevalence of H. pylori seropositivity increased with age. Parents and siblings of the infected children had 94% and 71% seropositivity, respectively, suggesting intrafamilial spread. Abnormal levels of IgG or IgA against H. pylori identified infected children with 95% sensitivity and 84% specificity. Eradication of the infection was accompanied by a significant decrease in IgG and IgA titers, with normalization in 10 cured patients in 12 months or less. We conclude that the method described for evaluation of H. pylori-specific IgG and IgA antibodies gives helpful information on the epidemiology of the infection and represents a useful adjunct to diagnosis and management of chronic gastritis in children.

Helicobacter pylori infection induces antibodies cross-reacting with human gastric mucosa

The authors' previous observation that many of the monoclonal antibodies against Helicobacter pylori cross-react with the cells of the human gastric mucosa prompted them to investigate the possibility that gastric self-antigens cross-reacting with H. pylori could be involved in the immune response against this organism. It was found that three antibodies against H. pylori, CB-4, CB-10, and CB-14, that cross-react with the human gastric mucosa also intensely cross-reacted with murine gastric epithelial cells. A strong reaction against autologous mucosa was also evident in the sera of mice immunized with H. pylori but not with other bacteria. A serological study performed in a group of 82 patients undergoing gastroscopy showed that the presence of seropositivity against H. pylori was strongly correlated with the presence of autoantibodies against human antral gastric mucosa. This activity was neutralized after absorption of the sera with H. pylori but not with other gram-negative bacteria. The antibodies in the mouse and in the human did not react with other segments of the gastrointestinal tract or with most of the other organs. Mice bearing hybridomas secreting a cross-reacting antibody (CB-4) had histopathologic abnormalities in their stomachs. These lesions were absent in the stomachs of mice bearing hybridomas secreting a non-cross-reacting antibody (CB-26). It was concluded that H. pylori infection can stimulate antibodies cross-reacting with gastric autoantigens and that this immunologic mechanism may represent a pathogenic link between H. pylori and gastritis.

Positive serum antibody and negative tissue staining for Helicobacter pylori in subjects with atrophic body gastritis

Helicobacter pylori is rarely found in gastric biopsy specimens from individuals with atrophic gastritis of the body mucosa. To determine if subjects with atrophic body gastritis have evidence of previous infection with H. pylori, immunoglobulin G antibody to H. pylori was measured by enzyme-linked immunosorbent assay in sera of 399 Finnish subjects. In 124 subjects, multiple biopsy specimens from body and antrum had been evaluated for the presence of H. pylori by Giemsa staining. Antibody correlated well with H. pylori staining except in the subgroup with atrophic body gastritis, in whom the prevalence of seropositivity (86%) was significantly greater than the prevalence of positive staining (33%) (P less than 0.001). Twenty-five subjects had positive antibody and negative staining. This group had a significantly higher prevalence of atrophic body gastritis (80%), lower maximal acid output, lower serum pepsinogen I levels, and higher serum gastrin concentrations than did seropositive subjects with H. pylori. These data suggest that most patients with atrophic body gastritis, despite having a low incidence of current overt infection, have been infected with H. pylori at some point in their lives.

Basophil-bound and serum immunoglobulin E directed against Helicobacter pylori in patients with chronic gastritis

The immunoglobulin (Ig) E immune response in patients with Helicobacter pylori-associated chronic gastritis has been evaluated. Of 26 patients with H. pylori infection, 22 (84%) tested positive for basophil-bound specific IgE (determined by the histamine release test) and 18 (69%) for serum specific IgE (determined by an enzyme-linked immunosorbent assay). In contrast, only 1 of 17 persons in whom the bacterium was not detected presented cell-bound and serum specific IgE. In the 4 histamine release test--positive but enzyme-linked immunosorbent assay--negative patients, removal of antibody from the basophil surface by acid elution showed that histamine release occurred through an IgE-dependent mechanism. When normal basophils, passively sensitized with serum from IgE-positive patients, were exposed to the H. pylori antigen, a significant release was observed, confirming the class specificity of the response. Inhibition experiments with bacteria other than H. pylori showed that the IgE antibody was specifically directed against this organism. The percentage of antigen-induced histamine release did not correlate with serum specific IgE level. However, the response of basophils to antigenic challenge was proportional to IgE-dependent cellular releasability. This finding suggests that target cell sensitivity may be the most important factor in determining the entity of biological response to the antigenic challenge. The ability of H. pylori to induce a specific IgE immune response could answer key questions regarding the mechanisms inducing gastric inflammation.

Oral immunization against Helicobacter pylori

Helicobacter pylori, which has been associated with gastritis and duodenal ulcers, commonly chronically infects adults. Eradication of this microorganism, which is difficult to achieve, results in normalization of gastritis and marked reduction in the relapse rate of duodenal ulcers. Since eradication is difficult to achieve, prevention of initial colonization of the gastrointestinal tract may be a viable alternative for abrogation of H. pylori-associated gastroduodenal disease. To test the feasibility of this approach, mice and ferrets were orally immunized with killed H. pylori. Immunization induced immunoglobulin A and G anti-H. pylori antibodies in both gastrointestinal secretions and sera of mice. These responses were enhanced when cholera toxin was included in the immunization protocol as a mucosal adjuvant. In ferrets, addition of cholera toxin resulted in significant enhancement of anti-H. pylori antibody levels in sera and intestines. Thus, oral immunization with killed H. pylori may be feasible approach to protect hosts from this infection and the accompanying gastroduodenal disease.

Epidemiology of Helicobacter pylori in an asymptomatic population in the United States. Effect of age, race, and socioeconomic status

A causative role is now accepted for Helicobacter (formerly Campylobacter) pylori in type B gastritis, and evidence is accumulating that H. pylori infection plays a major contributory role in peptic ulcer disease. Preliminary studies have reported that the prevalence of H. pylori infection increases with age, but detailed information on the prevalence of the bacteria in any defined population and on the factors that may influence the pattern of distribution remains scanty. In the present study, a sensitive enzyme-linked immunosorbent assay and a [13C] urea breath test were used to investigate the prevalence of H. pylori infection among 485 healthy asymptomatic volunteers between the ages of 15 and 80 residing in the Houston metropolitan area. H. pylori infection was present in 52%. The prevalence of H. pylori infection increased rapidly with age at 1%/yr for the overall population. The frequency of H. pylori infection was higher in blacks (70%) than whites (34%) (P less than 0.001); this difference remained after adjustments were made for age, gender, educational level, income, and use of tobacco or alcohol. H. pylori infection was independent of gender but was closely correlated with socioeconomic class. There were significant inverse correlations between age-adjusted frequency of H. pylori infection and income and between educational level and H. pylori infection. There was no association between H. pylori infection and consumption of alcohol or nonsteroidal antiinflammatory drug use or smoking. Having pets was associated with a lower frequency of H. pylori infection, but this was highly associated with higher socioeconomic status. The mode(s) of transmission of H. pylori is unknown, but the social patterns of H. pylori infection are consistent with fecal-oral transmission as one important pathway. Socioeconomic factors seem to determine the age of acquisition.

Diagnostic efficiency of an ultrarapid endoscopy room test for Helicobacter pylori

There are several reliable methods for detecting Helicobacter pylori but all have as a major disadvantage the time required to yield a definitive result. We have modified the standard urease test so that a positive result is available in one minute. We describe the use of this test in biopsy specimens from the gastric antrum from 220 consecutive patients referred for upper gastrointestinal endoscopy. The performance of the 'one minute test' was compared with a standard urease test, Gram stain, and microbiological culture. Using culture as the 'gold standard' 80 (36%) of the patients were H pylori positive. The one minute test produced no false positives and showed a sensitivity of 89% and specificity of 100%, while the predictive values of a positive and negative test were 100% and 94% respectively. The diagnostic efficiency of the test was 96% compared to 85% for both the Gram stain and direct urease test. All positive results using the one minute test were available within one minute. The test is easy to prepare and costs approximately pounds 0.04. This new modification of the urease test should be superior to the currently available urease tests because a reliable result will be available in almost 90% of infected individuals even before endoscopy is completed.

Evaluation of a commercial ELISA for serodiagnosis of Helicobacter pylori infection

A commercial ELISA for the detection of Helicobacter pylori IgG antibodies was evaluated using serum from 242 patients attending an endoscopy clinic. The efficacy of the ELISA was assessed in relation to the histological detection of H pylori on antral mucosal biopsy specimens. In patients under 61 years of age (n = 138) the ELISA was 97.5% sensitive and 85.5% specific for H pylori infection, with a positive predictive value of 91% and a negative predictive value of 96%. Over the whole group the sensitivity of the ELISA was 93.8% and the specificity 79.3%. The positive predictive value and negative predictive values were, respectively, 90% and 87%. These results suggest that the Bio-Rad GAP IgG H pylori ELISA is suitable for serodiagnosis of H pylori infections for most clinical purposes and thus makes H pylori serology available to routine diagnostic laboratories.

Implications for persistent chlamydial infections of phagocyte-microorganism interplay

In vitro models of Chlamydia trachomatis inhibition by cytokines, human-monocyte derived macrophages (HMDM) and human polymorphonuclear leukocytes (HPMN) are discussed in an attempt to delineate the molecular basis of parasite-host cell interplay in persistent and chronic chlamydial infection. Interferon gamma (IFN) has been found to reversibly inhibit chlamydial growth at an early stage in the replicative cycle, while tumor necrosis factor (TNF) has a more profound effect on chlamydial growth resulting in production of aberrant reticulate bodies and enhancement of production of prostaglandin E2 (PGE2). Chlamydia trachomatis (serovar L2) replicate in HMDM while serovar K has been found to be restricted in these cells. Chlamydiae are killed by HPMN but the cell walls persist undegraded, inducing production of oxygen radicals which can be demonstrated to induce DNA strand scissions in HeLa target cells. Evidence is accumulating that chlamydia specific serum IgA antibodies may serve as a noninvasive serological marker for diagnosis of a number of acute and persistent Chlamydia trachomatis infections.

Diagnosis of Campylobacter pylori gastritis

Campylobacter pylori is a bacterium that inhabits gastric mucosa. It causes chronic active gastritis and is highly associated with duodenal ulcer. Campylobacter pylori has a urease enzyme (not present in man), which allows diagnosis by a [14C]urea breath test. We compared two noninvasive tests, the breath test and serum ELISA, to biopsy and histologic diagnosis. Twenty-two patients who underwent gastroduodenoscopy for evaluation of possible peptic ulcer disease entered the study. The breath test detected the organism in eight of eight patients biopsy-positive for the organism (sensitivity 100%). The breath test was negative in 12 of the 14 patients who were biopsy-negative (specificity 86%). The ELISA was performed in 14 patients. It was positive in 5 of 5 patients biopsy-positive for the organism (sensitivity 100%) and negative in 7 of 9 patients who were biopsy-negative (specificity 78%). We conclude that both the ELISA and the [14C]urea breath test are excellent noninvasive methods to detect Campylobacter pylori. However, only the breath test is suitable for following the response to treatment, as it detects the presence of the organism rather than an immune response to it.

Relationship between gastric inflammatory response and symptoms in patients infected with Helicobacter pylori

The relationship between the histologic severity of gastritis and associated symptoms was examined in 19 adult patients infected with Helicobacter pylori. At the time of gastrointestinal endoscopy, symptoms of dyspepsia were assessed by means of a linear analog scale. Gastric inflammation was quantitated with histomorphometric techniques. Symptoms such as epigastric pain, burping/belching, and nausea correlated with the degree of inflammation. These positive correlations suggest that the severity of the histologic gastritis contributes to the severity of symptoms. Therefore, utilization of a linear analog scale to assess symptoms may be a useful technique in evaluating the outcome of therapeutic trials of patients with symptomatic H. pylori infection.

Helicobacter pylori infection rates in relation to age and social class in a population of Welsh men

The seroprevalence of IgG antibodies to Helicobacter pylori was determined using a standard enzyme linked immunosorbent assay in a population of 749 randomly selected men, aged 30-75 years, from Caerphilly, South Wales. The overall prevalence of H pylori was 56.9%, increasing sharply in middle age from 29.8% in those aged 30-34 to over 59% in those aged 45 or older (p less than 0.0001). Age standardised seroprevalence rates were lowest in combined social class categories I and II (49.2%), intermediate in categories IIIN and M (57.5%), and highest in categories IV and V (62.2%) (p = 0.01). In those aged 30-34 years, the prevalence rate for those in combined social class categories IV and V was 57.9% - double the rate for social class categories IIIM and N (28.3%) and five times the prevalence rate in those in social class categories I and II (11.1%). These differences in the infection patterns of H pylori by social class are consistent with patterns of peptic ulcer disease and gastric cancer.

Helicobacter pylori and progressive gastric pathology that predisposes to gastric cancer

Evidence is presented suggesting that infection by Helicobacter pylori triggers and continuously contributes to the pathophysiology of progressive gastric changes that can ultimately lead to gastric cancer. In Peru, especially in population groups of low socioeconomic status, infection by H. pylori begins earlier in life and is more prevalent and persistent than in developed countries. The infection produces a destructive lesion of the mucinous surface epithelium which probably enables other aggressive luminal factors to cause further mucosal damage. As a consequence, active chronic gastritis appears. The gastritis is of the superficial type at the beginning but may progressively change to atrophic. Chronic atrophic gastritis is found more frequently and at a younger age in dyspeptic patients with low socioeconomic status--that is, in patients having higher prevalence of persistent infection by H. pylori since earlier in life. When chronic atrophic gastritis becomes severe and extensive, hypochlorhydria ensues. Hypochlorhydria favors the appearance of bacterial overgrowth, nitrites, and N-nitroso compounds in the gastric lumen. N-nitroso compounds, because of their mutagenic-carcinogenic properties, probably induce gastric premalignant lesions like intestinal metaplasia and dysplasia of the gastric mucosa. Oral bismuth therapy apparently reverses H. pylori-associated gastric dysplasia. It is proposed that future programs designed for the control of gastric cancer would be incomplete if they do not include further evaluation of the many effects of infection by H. pylori on the gastric mucosa and of cost-effective methods to eradicate the infection.

Seroepidemiology of Helicobacter pylori infection in Greece

Helicobacter pylori infection is strongly associated with chronic gastritis and peptic ulceration. As the prevalence of H. pylori infection in southern European populations is not known, a serological survey of 1069 samples from three different age groups in the Greek population was carried out with an enzyme-linked immunosorbent assay (ELISA) for antibodies to these bacteria. The antigen was an ultracentrifuged supernate of whole cell sonicates of 5 isolates of H. pylori assessed by electrophoresis and by immunoblotting with negative and positive sera. The sensitivity of the test was 97.43% and the specificity 100% for IgG antibodies; IgA and IgM antibodies to the antigen preparation were not found. Antibodies to H. pylori were detected among 39.4% of children aged 1-10 years, 67.1% of recruits (20-27 years) and 70% of blood donors (20-50 years). The prevalence of antibodies did not differ with sex in each of the age groups. The proportion of individuals with antibodies to H. pylori was higher in the younger age groups than those reported for similar age groups in western Europe.

Antibody to cytotoxin in infection by Helicobacter pylori

Gastrointestinal disease and colonization by Helicobacter pylori were determined in 36 asymptomatic volunteers and 30 symptomatic individuals undergoing endoscopy and biopsy. Serum antibody immunoglobulin G (IgG) and IgA to H. pylori were measured by enzyme-linked immunosorbent assay. Serum antibody to a cytotoxin produced by H. pylori was detected with a neutralization assay. Serum IgG was 95% predictive of infection by H. pylori, and serum IgA was 88% predictive. Antibody to the cytotoxin was detected in 12 of 18 infected individuals. Antibody to the cytotoxin was a highly specific (96%), but not a very sensitive (67%), indicator of infection by H. pylori. The neutralization assay was 87% predictive of infection. These data confirm the diagnostic value of serum antibody to H. pylori for the detection of infection. The toxin-neutralizing activity of sera from individuals infected with H. pylori suggests that the cytotoxin is produced in vivo. It may therefore contribute to disease associated with H. pylori.

Helicobacter pylori: controversies and an approach to management

Helicobacter pylori (formerly, Campylobacter pylori) is a gram-negative, spiral-shaped bacterium with a strong affinity for gastric-type epithelium. Convincing evidence indicates that H. pylori plays an etiologic role in the development of chronic, nonspecific gastritis, and it may play an important role in the pathogenesis of duodenal ulcer disease. An etiologic role for this organism in chronic gastric ulceration, nonulcer dyspepsia, and gastric carcinoma is not established. Whereas the diagnosis of H. pylori infection is relatively straightforward, the questions of when and how to treat the infection do not have established answers. A high rate of recrudescence follows most currently used therapeutic interventions. Until the pathogenicity of H. pylori in clinical disease is further supported and additional treatment trials have been completed, a conservative management approach is recommended.

Intrafamilial clustering of Helicobacter pylori infection

Colonization of the gastric antrum by Helicobacter pylori (formerly Campylobacter pylori) has been associated with primary gastritis. We determined the frequency of colonization by H. pylori in gastric-antrum biopsy specimens from 93 children undergoing gastroscopy for the evaluation of upper gastrointestinal symptoms. We also determined H. pylori IgG antibody levels by enzyme-linked immunosorbent assay in coded serum samples from these children, family members, and control subjects of comparable ages. Among 27 children with primary, or unexplained, gastritis, H. pylori was identified by silver staining in 24 biopsy specimens and by culture in 22; specific antibodies were present in 23 children (96 percent). Three children with unexplained gastritis had no evidence of H. pylori in the antrum, nor did any of 13 children with secondary gastritis or any of 53 children with normal antral histologic features; specific antibodies were present in only 1 of these 69 children. H. pylori antibody was detected in 25 of 34 parents of colonized children, but in only 8 of 33 parents of noncolonized children (P less than 0.001). Of 22 siblings of children colonized by H. pylori, 18 had specific antibodies, as compared with only 5 of 37 controls (P less than 0.001). We conclude that H. pylori-specific IgG antibodies are associated with bacterial colonization of the gastric antrum by this organism. The intrafamilial clustering of H. pylori infection suggests that there may be person-to-person spread of these bacteria.

Identification of Campylobacter pylori by endoscopic brush cytology

To investigate the value of Papanicolaou-stained endoscopic brush samples in the diagnosis of Campylobacter pylori infection of the upper gastrointestinal tract, 138 brush and biopsy samples from the esophagus, stomach, and duodenum, taken concomitantly, were reviewed retrospectively. In 35 cases, Campylobacter-like organisms (CLOs) were found in both cytology and biopsy samples. In 15 cases, CLOs were seen in biopsy material only, and in 8 cases, CLOs were found in cytology material only. CLOs were found in 49% of the gastric specimens and 33% of the Barrett's esophagus specimens by histologic or cytologic examination or by both methods. CLOs were found by at least one method in 64% of the gastric samples with active gastritis 40% with borderline gastritis, 15% without gastritis, and in 64% with adenocarcinoma. Cytologic examination of endoscopic brush samples is a valuable technique for the diagnosis of gastric Campylobacter infections and can be performed easily in cytopathology laboratories.