Tamara Vorobjova

An 18-Year Follow-up Study of Chronic Gastritis and Helicobacter pylori: Association of CagA Positivity with Development of Atrophy and Activity of Gastritis

BACKGROUND We wanted to evaluate the course of chronic gastritis and its association with Helicobacter pylori and CagA seropositivity in an adult sample from Saaremaa (Estonia) during an 18-year follow-up. METHODS Seventy persons (31 men, 39 women; median age, 57.5 years) from a primary sample of 304 subjects endoscoped in 1979 were reinvestigated by endoscopy and biopsy in 1997. The state of the gastric mucosa and the presence of H. pylori in histologic sections from the antrum and corpus were assessed both in 1979 and 1997 in 66 subjects in accordance with the Sydney system, and H. pylori status in all 70 subjects was determined with the enzyme-linked immunosorbent assay (ELISA). Anti-CagA IgGs were determined with the ELISA, using the recombinant fragment of CagA. RESULTS During an 18-year follow-up 11% of the subjects developed atrophy in the antrum, whereas 35% developed it in the corpus. Development of atrophy in the corpus and the appearance of intestinal metaplasia in the antrum were associated with increased activity of gastritis both in the initial and last follow-up biopsies. Anti-CagA positivity was found in 71% of H. pylori-seropositive persons (94% of subjects). There was a significant association between CagA positivity and the activity of gastritis, the presence of atrophy or damage to surface epithelial cells in the antrum and in corpus mucosal biopsy specimens at the last follow-up endoscopy. CONCLUSION The CagA-positive strains of H. pylori enhance the development of atrophic gastritis compared with CagA-negative strains.

Increased FOXP3 expression in small-bowel mucosa of children with coeliac disease and type I diabetes mellitus

Objective. To determine whether the expression of FOXP3 is changed in small-bowel mucosa in coeliac disease (CD). Material and methods. The study comprised 52 patients (mean age 8.01±6.14 years) who had undergone small-bowel biopsies. CD only was diagnosed in 16 patients, and CD with type I diabetes mellitus (T1D) in 7. These 23 patients and 4 others without CD had partial or subtotal villous atrophy (PVA, SVA). Twenty-five persons without CD had normal mucosa. The transcription level of the FOXP3 gene (Hs00203958_m1) was evaluated in biopsy samples (small bowel) using TaqMan gene expression assays. FOXP3 protein in mucosal cells was evaluated with mouse anti-human FOXP3 antibodies and CD25+, and CD4+ T cells were evaluated by mouse monoclonal antibodies. Results. Expression of FOXP3 mRNA was higher in both PVA and SVA compared to normal mucosa (p=0.007). Patients with CD and T1D had higher expression of FOXP3 mRNA than patients with CD alone (p=0.02). The number of FOXP3+ cells in intestinal mucosa was higher in patients with CD, especially those with coexisting T1D, than in those with normal mucosa (p=0.01). The results of double staining showed that, among all positive cells, FOXP3 expression alone was revealed in 25.6% of the cells, CD25 positivity in 18% and both markers simultaneously were found in 56.5% of lymphocytes (p=0.03). Double staining for CD4 and FOXP3 showed that 87.5% of cells were CD4+, 2.8% were FOXP3+ and 9.7% of cells simultaneously expressed the CD4 and FOXP3 markers. Conclusions. A more pronounced expression of FOXP3 mRNA and also the number of FOXP3+ cells (with simultaneous expression of CD25 and CD4 markers) were found in the small-bowel biopsy specimens obtained from children with CD, particularly those with coexisting T1D, compared with the FOXP3 expression in normal mucosa.

Helicobacter pylori infection in children in Estonia: Decreasing seroprevalence during the 11-year period of profound socioeconomic changes

Background.  The prevalence of Helicobacter pylori infection is inversely associated with socioeconomic conditions in childhood. In Estonia, a high prevalence of H. pylori infection has been observed among children born in 1987 and earlier. Since 1991, after the dissolution of the USSR, profound social and economic changes have taken place in the country. The aim of the study was to evaluate changes in the seroprevalence of H. pylori infection among children in the period 1991–2002.

Immune responses to bile-tolerant Helicobacter species in patients with chronic liver diseases, a randomized population group, and healthy blood donors

ABSTRACT Bile-tolerant Helicobacter species such as Helicobacter pullorum, Helicobacter bilis, and Helicobacter hepaticus are associated with hepatic disorders in animals and may be involved in the pathogenesis of chronic liver diseases (CLD) in humans. Antibody responses to cell surface proteins of H. pullorum, H. bilis, and H. hepaticus in serum samples from patients with CLD, a randomized population group, and healthy blood donors were evaluated by using enzyme linked immunosorbent assay (ELISA). The results were compared with the antibody responses to Helicobacter pylori. For analysis of a possible cross-reactivity between bile-tolerant Helicobacter species and H. pylori, sera from a subpopulation of each group were absorbed with a whole-cell extract of H. pylori and retested by ELISA. Results before absorption showed that the mean value of the ELISA units for H. pullorum was significantly higher in patients with CLD than in healthy blood donors (P = 0.01). Antibody reactivity to cell surface protein of H. hepaticus was also significantly higher in the CLD patients than in the healthy blood donors and the population group (P = 0.005 and P = 0.002, respectively). Following the absorption, antibody responses to H. pullorum decreased significantly in all three groups (P = 0.0001 for CLD patients, P = 0.0005 for the population group, and P < 0.0001 for the blood donors), indicating that cross-reactivity between H. pylori and other Helicobacter spp. occurs. The antibody responses to H. hepaticus and H. bilis in CLD patients remained high following absorption experiments compared to ELISA results before absorption. The significance of this finding requires further investigations.

CagA protein seropositivity in a random sample of adult population and gastric cancer patients in Estonia.

Objective The prevalence of antibodies to CagA protein, associated with the risk of developing gastric cancer (QC), was studied in an Estonian adult population with a high prevalence of Helicobacter pylori (HP) infection and in a group of GC patients. Design In a representative sample of a random adult population from the South Estonian town of Karksi-Nuia, containing 199 subjects (86 M, 113 F, mean age 42.4) and in 45 (22 M, 23 F, mean age 64.5) consecutive patients with gastric adenocarcinoma, recruited during the periods 1986–87 and 1995–96 in the Hospital of Oncology, University of Tartu, anti-CagA IgG antibodies were determined by enzyme-linked immunosorbent assay (ELISA) using a recombinant fragment of CagA protein. The occurrence of anti-CagA IgG in ELISA was compared with immunoblot results for 141 subjects. Results Seropositivity to acid glycine extracted cell surface proteins of HP was 85% in the population and 91% in GC patients (p = 0.39). Anti-CagA IgG antibodies were present in 63% of the population and in 87% of GC patients (p = 0.004). The highest prevalence of anti-CagA IgG in the population sample occurred in the age group 20–29 (76%). A comparison of anti-CagA positivity evaluated by using ELISA and immunoblot showed an agreement of results in 80% of cases. Conclusion HP seropositivity was similarly high in the Estonian random adult population sample and in GC patients, however, the prevalence of anti-CagA IgG was significantly higher in GC patients. Moreover, persons aged 20–29 years in the population possess the highest prevalence of anti-CagA IgG and should be given further attention with respect to the development of GC later in life.

Significant increase in antigastric autoantibodies in a long-term follow-up study of H. pylori gastritis

Abstract In 30% of H. pylori-infected patients a certain type of antigastric autoantibodies, reacting against canalicular structures within human parietal cells, is detectable. Furthermore, it has been shown that these autoantibodies are correlated with atrophy of the mucosa in the corpus. The aim of this study was to analyse the prevalence of these anticanalicular autoantibodies (ACAB) and their significance for development of gastric mucosa atrophy in a 12-year follow-up period. Gastric biopsy specimens from 62 persons in Saaremaa Island, Estonia, were collected in 1997 and assessed independently by two pathologists in accordance with the updated Sydney system. The sera of these persons were immunohistochemically screened for ACAB and for classic parietal cell antibodies (PCA). In addition, for 37 of the 62 persons, gastric biopsies and sera collected 12 years earlier (1985) were investigated in an analogous manner. ACAB increased significantly, from 8 out of 37 in 1985 to 17 out of 37 in 1997 (P=0.004; McNemar test). In 1997 a significant correlation existed between the presence of ACAB and corpus mucosa atrophy (19 out of 30 versus 10 out of 32 without atrophy; P=0.01; odds ratio (OR)=3.8, 95% CI 1.4–10.6). However, no correlation was found between ACAB and development of atrophy in the period from 1985 to 1997. All 37 persons were PCA negative in 1985, whereas in 1997, 2 turned out to be PCA positive. ACAB increased significantly with duration of H. pylori gastritis. The correlation between ACAB and presence of gastric corpus atrophy was confirmed. However, it is possible that ACAB are the consequence of and not a causative factor in gastric mucosa atrophy, insofar as the association of ACAB with progression of corpus atrophy was not significant.

Seropositivity to Helicobacter pylori and CagA protein in schoolchildren of different ages living in urban and rural areas in southern Estonia.

Objective To evaluate Helicobacter pylori and CagA seropositivity in a non‐selected group of schoolchildren in southern Estonia, with reference to previous studies where high seroprevalence to H. pylori (87%) and anti‐CagA positivity (63%) in an adult population from the same region were found. Study population A total of 421 schoolchildren selected haphazardly from a random population (n = 1018, ages 9, 12 or 15 years) and living in urban or rural areas. Methods H. pylori status was determined by evaluation of IgG antibodies against cell surface proteins of H. pylori, strain CCUG 17874, using standard ELISA. Anti‐CagA IgGs were determined by ELISA using a recombinant fragment of CagA (CCUG 17874) as solid‐phase antigen. Absorbance values > 0.3 (405 nm) were taken as a CagA‐positive result based on a study of 25 sera from H. pylori‐negative children. Results Of the 421 subjects, 235 (56%) were H. pylori‐ELISA positive, and 109 out of the 235 (46%) were anti‐CagA positive. Neither H. pylori nor CagA positivity were significantly different in girls and boys, or in children aged 9, 12 or 15 years. The H. pylori prevalence rate (118/181, 65%) as well as CagA positivity (64/181, 35%) in rural areas were higher compared with those in towns (117/240, 49% and 54/240, 22%, respectively; P = 0.001 and P = 0.005). Conclusion Of schoolchildren living in southern Estonia, 56% were seropositive to H. pylori. Half of them had anti‐CagA antibodies. Schoolchildren living in rural areas were infected significantly more often with CagA‐seropositive strains compared with those living in towns. Eur J Gastroenterol Hepatol 12:97‐101

The prevalence of Helicobacter pylori antibodies in a population from southern Estonia

Objectives Previous retrospective histological studies have revealed a Helicobacter pylori infection rate of 73–79%. Cross-sectional studies on H. pylori prevalence are still lacking in Estonia. Design A total of 1461 inhabitants between the ages of 15 and 95 years from the village of Karksi-Nuia and 497 between the ages of 50 and 91 years from Abja-Paluoja were examined for IgG antibodies to H. pylori. This study was performed on a quasi-global sample of the general adult rural population in two villages in southern Estonia. Method A cell-surface glycine extract of H. pylori strain NCTC 11637 was used as antigen in an enzyme-linked immunosorbent assay. Results IgG antibodies to H. pylori strain NCTC 11637 were detected in 87.0±2.3% of the inhabitants of Karksi-Nuia and in 89.3±3.6% of those from Abja-Paluoja. IgG prevalence rates increased from 69.0±9.5% in the 15− to 19-year-old age group to 83.0±7.1% in the 20− to 29-year-olds (P<0.05). Conclusion We found an extremely high prevalence rate of H. pylori infection in this Estonian adult rural population. H. pylori infection was very prevalent among young people (aged 15–29 years).

Apoptosis in different compartments of antrum and corpus mucosa in chronic Helicobacter pylori gastritis. An 18-year follow-up study.

BACKGROUND The association of apoptosis was analysed in three different compartments (foveolar cells--FC, proliferating zone--PZ and glandular part--GP) of antrum and corpus mucosa specimens with development of atrophy and the extent of apoptosis as depending on grade of chronic inflammation, activity of gastritis and Helicobacter pylori colonization at two time points of an 18-year follow-up in an adult population from Saaremaa, Estonia, with a high prevalence of H. pylori infection were compared. METHODS A total of 68 persons (31 men, 37 women; median age, 39 years in 1979) from a primary sample of 304 subjects, endoscoped in 1979 and reinvestigated by endoscopy and biopsy in 1997, were included in the study. The state of the gastric mucosa and the presence of H. pylori in the antrum and corpus mucosa were assessed in accordance with the Sydney system. The dynamics of apoptotic index (AI) between two time points in 1979 and 1997 was evaluated in antrum biopsies of 49 persons and in corpus biopsies of 64 persons. Apoptosis was measured using terminal deoxyuridine nucleotide nick end labelling (TUNEL) histochemistry. RESULTS The antrum as well as the corpus of 2/68 persons were H. pylori negative at both time points. Atrophy developed in 9/68 persons in the antrum and in 23/68 in the corpus. In PZ and GP of the corpus mucosa as well as in GP of the antrum mucosa, AI decreased significantly during 18 years compared with initial values (P < 0.05), which was not associated with development of atrophy. In all compartments of the antrum and corpus mucosa, studied at the initial and end points of observation, AI did not reveal a difference in persons with and without development of atrophy (P > 0.05). In the samples of 1979 the highest independent effect on the value of AI in the FC compartment for the antrum was exerted by grade of activity of gastritis (P = 0.01) and in GP by degree of chronic inflammation (P = 0.03), while in the samples of 1997 the highest effect was exerted by grade of H. pylori colonization (P = 0.02 and 0.03 in FC and GP, respectively). For the corpus mucosa AI was most strongly affected also by grade of activity of gastritis in FC compartment (P = 0.02) and by degree of chronic inflammation in PZ (P = 0.04), but not by grade of H. pylori colonization. CONCLUSION AI was not associated with development of atrophy, but was largely dependent on grade of activity of gastritis and degree of chronic inflammation; in the antrum mucosa AI depended also on grade of H. pylori colonization.Background: The association of apoptosis was analysed in three different compartments (foveolar cells- FC, proliferating zone-PZ and glandular part-GP) of antrum and corpus mucosa specimens with development of atrophy and the extent of apoptosis as depending on grade of chronic inflammation, activity of gastritis and Helicobacter pylori colonization at two time points of an 18-year follow-up in an adult population from Saaremaa, Estonia, with a high prevalence of H. pylori infection were compared. Methods: A total of 68 persons (31 men, 37 women; median age, 39 years in 1979) from a primary sample of 304 subjects, endoscoped in 1979 and reinvestigated by endoscopy and biopsy in 1997, were included in the study. The state of the gastric mucosa and the presence of H. pylori in the antrum and corpus mucosa were assessed in accordance with the Sydney system. The dynamics of apoptotic index (AI) between two time points in 1979 and 1997 was evaluated in antrum biopsies of 49 persons and in corpus biopsies of 64 persons. Apoptosis was measured using terminal deoxyuridine nucleotide nick end labelling (TUNEL) histochemistry. Results: The antrum as well as the corpus of 2/68 persons were H. pylori negative at both time points. Atrophy developed in 9/68 persons in the antrum and in 23/68 in the corpus. In PZ and GP of the corpus mucosa as well as in GP of the antrum mucosa, AI decreased significantly during 18 years compared with initial values (P < 0.05), which was not associated with development of atrophy. In all compartments of the antrum and corpus mucosa, studied at the initial and end points of observation, AI did not reveal a difference in persons with and without development of atrophy (P > 0.05). In the samples of 1979 the highest independent effect on the value of AI in the FC compartment for the antrum was exerted by grade of activity of gastritis (P = 0.01) and in GP by degree of chronic inflammation (P = 0.03), while in the samples of 1997 the highest effect was exerted by grade of H. pylori colonization (P = 0.02 and 0.03 in FC and GP, respectively). For the corpus mucosa AI was most strongly affected also by grade of activity of gastritis in FC compartment (P = 0.02) and by degree of chronic inflammation in PZ (P = 0.04), but not by grade of H. pylori colonization. Conclusion: AI was not associated with development of atrophy, but was largely dependent on grade of activity of gastritis and degree of chronic inflammation; in the antrum mucosa AI depended also on grade of H. pylori colonization.

Helicobacter pylori: Histological and Serological Study on Gastric and Duodenal Ulcer Patients in Estonia

We have examined the occurrence of Helicobacter pylori (HP) infection in 86 Estonian gastric ulcer (GU) and 25 duodenal ulcer (DU) patients. Diagnosis of the HP infection was made histologically (modified Giemsa) from gastric biopsy specimens, and serologically by parallel use of two enzyme-linked immunosorbent assays for IgG antibodies to HP in patient sera. The infection was diagnosed simultaneously by all three methods in 84% of the GU and 84% of the DU patients. The infection was revealed histologically in 88% of the GU and 92% of the DU patients, and serologically by either of the two methods in 94% and 92% of the GU and DU patients, respectively. HP infection was absent by all three methods in one GU patient only, this patient being the only subject who showed normal gastric mucosa in conventional histology. These observations show that HP infection is very common in patients with peptic ulcer in Estonia. In addition, the findings suggest that the serological assays will find a small proportion (15%) of ulcer patients with antibodies against HP but no histologically detectable bacteria.