Mónica Roxo-Rosa

Revertant mutants G550E and 4RK rescue cystic fibrosis mutants in the first nucleotide-binding domain of CFTR by different mechanisms

The revertant mutations G550E and 4RK [the simultaneous mutation of four arginine-framed tripeptides (AFTs): R29K, R516K, R555K, and R766K] rescue the cell surface expression and function of F508del-cystic fibrosis (CF) transmembrane conductance regulator (-CFTR), the most common CF mutation. Here, we investigate their mechanism of action by using biochemical and functional assays to examine their effects on F508del and three CF mutations (R560T, A561E, and V562I) located within a conserved region of the first nucleotide-binding domain (NBD1) of CFTR. Like F508del, R560T and A561E disrupt CFTR trafficking. G550E rescued the trafficking defect of A561E but not that of R560T. Of note, the processing and function of V562I were equivalent to that of wild-type (wt)-CFTR, suggesting that V562I is not a disease-causing mutation. Biochemical studies revealed that 4RK generates higher steady-state levels of mature CFTR (band C) for wt- and V562I-CFTR than does G550E. Moreover, functional studies showed that the revertants rescue the gating defect of F508del-CFTR with different efficacies. 4RK modestly increased F508del-CFTR activity by prolonging channel openings, whereas G550E restored F508del-CFTR activity to wt levels by altering the duration of channel openings and closings. Thus, our data suggest that the revertants G550E and 4RK might rescue F508del-CFTR by distinct mechanisms. G550E likely alters the conformation of NBD1, whereas 4RK allows F508del-CFTR to escape endoplasmic reticulum retention/retrieval mediated by AFTs. We propose that AFTs might constitute a checkpoint for endoplasmic reticulum quality control.

Revertants, Low Temperature, and Correctors Reveal the Mechanism of F508del-CFTR Rescue by VX-809 and Suggest Multiple Agents for Full Correction

Cystic fibrosis is mostly caused by the F508del mutation, which impairs CFTR protein from exiting the endoplasmic reticulum due to misfolding. VX-809 is a small molecule that rescues F508del-CFTR localization, which recently went into clinical trial but with unknown mechanism of action (MoA). Herein, we assessed if VX-809 is additive or synergistic with genetic revertants of F508del-CFTR, other correctors, and low temperature to determine its MoA. We explored and integrated those various agents in combined treatments, showing how they add to each other to identify their complementary MoA upon correction of F508del-CFTR. Our experimental and modeling data, while compatible with putative binding of VX-809 to NBD1:ICL4 interface, also indicate scope for further synergistic F508del-CFTR correction by other compounds at distinct conformational sites/cellular checkpoints, thus suggesting requirement of combined therapies to fully rescue F508del-CFTR.

Singlet oxygen in antimicrobial photodynamic therapy: Photosensitizer-dependent production and decay in E. coli

Several families of photosensitizers are currently being scrutinized for antimicrobial photodynamic therapy applications. Differences in physical and photochemical properties can lead to different localization patterns as well as differences in singlet oxygen production and decay when the photosensitizers are taken up by bacterial cells. We have examined the production and fate of singlet oxygen in Escherichia coli upon photosensitization with three structurally-different cationic photosensitizers, namely New Methylene Blue N (NMB), a member of the phenothiazine family, ACS268, a hydrophobic porphyrin with a single cationic alkyl chain, and zinc(II)-tetramethyltetrapyridinoporphyrazinium salt, a phthalocyanine-like photosensitizer with four positive charges on the macrocycle core. The kinetics of singlet oxygen production and decay indicate different localization for the three photosensitizers, whereby NMB appears to localize in an aqueous-like microenvironment, whereas ACS268 localizes in an oxygen-shielded site, highly reactive towards singlet oxygen. The tetracationic zinc(II) tetrapyridinoporphyrazine is extensively aggregated in the bacteria and fails to produce any detectable singlet oxygen.

Ulcerogenic Helicobacter pylori Strains Isolated from Children: A Contribution to Get Insight into the Virulence of the Bacteria

Infection with Helicobacter pylori is the major cause for the development of peptic ulcer disease (PUD). In children, with no other etiology for the disease, this rare event occurs shortly after infection. In these young patients, habits of smoking, diet, consumption of alcohol and non-steroid anti-inflammatory drugs and stress, in addition to the genetic susceptibility of the patient, represent a minor influence. Accordingly, the virulence of the implicated H. pylori strain should play a crucial role in the development of PUD. Corroborating this, our in vitro infection assays comparing a pool of five H. pylori strains isolated from children with PUD to a pool of five other pediatric clinical isolates associated with non-ulcer dyspepsia (NUD) showed the greater ability of PUD strains to induce a marked decrease in the viability of gastric cells and to cause severe damage in the cells cytoskeleton as well as an impairment in the production/secretion of mucins. To uncover virulence features, we compared the proteome of these two groups of H. pylori strains. Two-dimensional gel electrophoresis followed by mass-spectrometry allowed us to detect 27 differentially expressed proteins between them. In addition to the presence of genes encoding well established virulence factors, namely cagA, vacAs1, oipA “on” status, homB and jhp562 genes, the pediatric ulcerogenic strains shared a proteome profile characterized by changes in the abundance of: motility-associated proteins, accounting for higher motility; antioxidant proteins, which may confer increased resistance to inflammation; and enzymes involved in key steps in the metabolism of glucose, amino acids and urea, which may be advantageous to face fluctuations of nutrients. In conclusion, the enhanced virulence of the pediatric ulcerogenic H. pylori strains may result from a synergy between their natural ability to better adapt to the hostile human stomach and the expression of the established virulence factors.

Antigenic diversity among Portuguese clinical isolates of Helicobacter pylori

Background:  The human gastroduodenal pathogen, Helicobacter pylori, is characterized by an unusual extent of genetic heterogeneity. This dictates differences in the antigenic pattern of strains resulting in heterogeneous human humoral immune responses. Here, we examined the antigenic variability among a group of 10 strains isolated from Portuguese patients differing in age, gender, and H. pylori‐associated gastric diseases.

Proteome variability among Helicobacter pylori isolates clustered according to genomic methylation

To understand whether the variability found in the proteome of Helicobacter pylori relates to the genomic methylation, virulence and associated gastric disease.

A Nonionic Porphyrin as a Noninterfering DNA Antibacterial Agent

The increasing interest in clinical bacterial photodynamic inactivation has led to the search for photosensitizers with higher bactericidal efficiency and less side effects on the surrounding tissues. We present a novel nonionic porphyrin, the 5,10,15‐tris(2,6‐dichlorophenyl)‐20‐[4‐N‐(6‐amino‐hexyl)sulfonamido)phenyl]‐porphyrin (ACS769F4) with substantial improvements in the efficiency of nonionic sensitizers. This porphyrin causes eradication of both Escherichia coli and Staphylococcus aureus by the photodynamic effect but in higher concentrations compared with 5,10,15,20‐tetrakis (4‐N,N,N‐trimethylammoniumphenyl)‐porphyrin p‐tosylate (TTAP4+), a known bactericidal tetracationic porphyrin. More important, under such conditions, ACS769F4 proved to be harmless to two mammalian cells lines (human embryonic and baby hamster kidney), causing no reduction in their viability or negative impact on their cytoskeleton, despite its accumulation in cellular structures. On the contrary, TTAP4+ is shown to accumulate in the nucleus of mammalian cells, in association to DNA, causing chromatin condensation after exposure to light. Furthermore, dark incubation with TTAP4+ was shown to have a deleterious effect on the microtubule network. Based on its bactericidal efficiency, also observed without exposure to light, and on the low tendency to be harmful or genotoxic to mammalian cells, ACS769F4 should be looked at as an interesting photosensitizer to be evaluated for clinical purposes.

Helicobacter pylori—Associated Dyspepsia in Paediatrics

Helicobacter pylori ubiquitously infects the human gastric mucosa since time immemorial, predictably before the man’s diaspora out of East Africa around 58,000 years ago [1]. Colonization may have been somehow beneficial for human carriers, allowing the coevolution of this gram-negative bacterium and its host over the centuries. Yet, at least nowadays [2], this may not be a peaceful association, with infection almost invariably causing an acute host immune response. However, in a fully adapted manner, H. pylori avoids recognition and, thus, clearance, by the host immune system, with both infection and the consequent gastritis persisting throughout the patients’ life. The clinical outcome of this persistence is dependent on a sophisticated crosstalk between the host and the pathogen. If often asymptomatic, the H. pylori-associated non-ulcer dyspepsia is clearly the strongest aetiological factor for severe gastric diseases that will develop late in adult life in a minority of infected patients, i.e., peptic ulcer disease, both gastric and duodenal ulcers, and gastric cancer, namely, adenocarcinoma and mucosa associated lymphoid tissue (MALT) lymphoma (reviewed in [3]). Peptic ulcer disease rarely occurs soon after H. pylori infection [4-8] that generally starts in childhood; this presumably reflects marked differen‐ ces in the virulence [9-16] and/or in the susceptibility of young patients [17-19].

Ulcerogenic profile of helicobacter pylori pediatric strains: a contribution to get insight into the virulence of the Bacteria

no.: WS1.1 HELICOBACTER PYLORI INFECTION AND MARKERS OF GASTRIC CANCER RISK IN ALASKA NATIVE PEOPLE J. Keck,* K. Miernyk,* L. Bulkow,* J. Kelly, B. McMahon, F. Sacco, T. Hennessy* and M. G. Bruce* *Centers for Disease Control and Prevention, Anchorage, AK, USA; Alaska Native Tribal Health Consortium, Anchorage, AK, USA Background: Alaska Native gastric cancer incidence and mortality rates are 3 to 4-times higher than general US population rates. We evaluated pepsinogen I, pepsinogen I/II ratio, anti-H. pylori and CagA antibodies, and blood group to determine their association with gastric cancer development in Alaska Native people. Methods: We conducted a retrospective case-control study that matched gastric cancers reported to the Alaska Native Tumor Registry from 1969–2008 to three controls on known demographic risk factors for H. pylori infection, using previously collected sera from the Alaska Area Specimen Bank. Conditional logistic regression evaluated the associations between serum markers and gastric cancer. Results: We included 122 gastric cancer cases with sera predating cancer diagnosis (mean = 13 years) and 346 matched controls. One hundred and twelve cases (91.8%) and 285 controls (82.4%) had evidence of previous or ongoing H. pylori infection as measured by anti-H. pylori antibodies. Gastric cancer cases had 2.63-fold increased odds of positive anti-H. pylori antibodies compared with their matched controls (p = .01). In a multivariate model, non-cardia gastric cancer (n = 94) was associated with anti-H. pylori antibodies (adjusted OR 3.92, p = .004) and low pepsinogen I (aOR 6.04, p = .04). We found no association between gastric cancer and blood group, anti-CagA antibodies, or pepsinogen I/II ratio. Conclusions: Alaska Native people with gastric cancer had increased odds of previous H. pylori infection. Low pepsinogen I might function as a pre-cancer marker for non-cardia cancer. Impact: Future research to identify Alaska Native individuals with increased gastric cancer risk includes H. pylori genotype and host characteristic studies. Abstract no.: WS1.2 CLUSTERING OF HELICOBACTER PYLORI STRAINS FROM GASTRIC CANCER C. Wang, S. Zhan and Q. Dong Qingdao Municipal Hospital, Qingdao City, Chinano.: WS1.2 CLUSTERING OF HELICOBACTER PYLORI STRAINS FROM GASTRIC CANCER C. Wang, S. Zhan and Q. Dong Qingdao Municipal Hospital, Qingdao City, China Genetic differences between strains play an important role in the determination of clinical outcomes of Helicobacter pylori infection. This study aimed to determine the sequencing types of H. pylori strains from gastric cancer. Materials and Methods: Twenty-two strains of H. pylori were enrolled, including 12 strains from patients with gastric cancer. MLST was used to determine the sequencing type. Results: The seven genetic loci of H. pylori were PCR amplified and sequenced. Those sequences of the seven genes were concatenated, and aligned with the sequences of strains from Europe (5), Africa (5), Asia (5) and other parts of China (16) extracted from the MLST database. A neighbour-joining tree with a kimura 2-parameter model was subsequently constructed. The results showed that all 22 strains, as well as Asia strains from database fell into the HpEastAsia haplogroup which could divided into two groups, groups I and II. Group I consisted of seven cancer strains but only one non-cancer strain of H. pylori, in addition to five strains form database. Fisher’s exact test revealed a statistically significant difference (p = .027). Discussion and Conclusion: The clustering of cancer strains of H. pylori is consistent with a recent report showing that the phylogeopraphic origin of H. pylori is a determinant of gastric cancer risk. This may reflect the consequence of long-term interaction of the bacterium with individual hosts of different genetic ground. The results suggested that the sequencing types could possibly be used to predict the clinical outcomes of H. pylori infection. Abstract no.: WS1.3 LACK OF ASSOCIATION BETWEEN GENE POLYMORPHISMS OF ANGIOTENSIN CONVERTING ENZYME, NOD-LIKE RECEPTOR 1, TOLL-LIKE RECEPTOR 4 AND FAS/FASL WITH THE PRESENCE OF HELICOBACTER PYLORI-INDUCED PREMALIGNANT GASTRIC LESIONS AND GASTRIC CANCER IN CAUCASIANS J. Kupcinskas,* T. Wex, J. Bornschein, M. Selgrad, M. Leja, L. Jonaitis* and P. Malfertheiner *Department of Gastroenterology, Lithuanian University of Health Sciences, Kaunas, Lithuania; Clinic of Gastroenterology, Hepatology and Infectious Diseases, Otto von Guericke University, Magdeburg, Germany; Faculty of Medicine, University of Latvia, Digestive Diseases Center, Hospital Lizeners, Riga, Latvia Background: Several polymorphisms of genes involved in the immunological recognition of Helicobacter pylori and regulating apoptosis and proliferation have been linked to gastric carcinogenesis, however reported data are partially conflicting. The aim of our study was to evaluate potential associations between the presence of gastric cancer (GC) and high risk atrophic gastritis (HRAG) and polymorphisms of genes encoding Angiotensin converting enzyme (ACE), Nod-like receptor 1 (NOD1), Toll-like receptor 4 (TLR4) and FAS/FASL. Methods: Gene polymorphisms were analyzed in 574 subjects (GC: n = 114; HRAG: n = 222, controls: n = 238) of Caucasian origin. ACE I/D (rs4646994), NOD1 796G>A (rs5743336), TLR4 3725G>C (rs11536889), FAS 1377G>A (rs2234767), FAS 670A>G (rs1800682) and FASL 844T>C (rs763110) were genotyped by different PCR approaches and RFLP analysis. Results: Frequencies of genotypes in our study are similar to the data reported on subjects of Caucasian ethnicity. There was a tendency for NOD1 796G/G genotype to be associated with increased risk of HRAG (62.4% vs 54.5% in controls, p = .082). FAS 670G/G genotype was more frequent in HRAG when compared to controls, 23.9% and 17.2% respectively, however it failed to reach significance level (p = .077). We did not find any significant associations for all examined polymorphism in relation to GC or HRAG. NOD1 796G>A and TLR4 3725G>C gene polymorphisms were also not linked with Helicobacter pylori seropositivity status. Conclusions: ACE, NOD1, TRL4 and FAS/FASL gene polymorphisms are not linked with gastric carcinogenesis in Caucasians, and therefore they should not be considered as potential biomarkers for identifying individuals with higher risk for GC. Abstract no.: WS1.4 ATROPHIC GASTRITIS BY THE OLGA STAGES AND HELICOBACTER CAGA SEROPOSITIVITY IN GASTRIC CANCER T. Vorobjova,* K. Kull,* H. Saar,* R. Labotkin,* A. Zimmermann and H. Maaroos* *University of Tartu, Tartu, Estonia; University of Bern, Bern, Switzerlandno.: WS1.4 ATROPHIC GASTRITIS BY THE OLGA STAGES AND HELICOBACTER CAGA SEROPOSITIVITY IN GASTRIC CANCER T. Vorobjova,* K. Kull,* H. Saar,* R. Labotkin,* A. Zimmermann and H. Maaroos* *University of Tartu, Tartu, Estonia; University of Bern, Bern, Switzerland Introduction: Operative Link on Gastritis Assessment (OLGA) express extent of gastric atrophy in terms of gastritis staging, which severity should be related to gastric cancer. Aim: To study how the OLGA stages of atrophic gastritis are associated with the morphological type, and Helicobacter pylori CagA positivity in gastric cancer. Patients: Twenty two gastric carcinoma patients (8 male, 14 female; mean age 64 ± 12) were operated on. The intestinal type of carcinoma was diagnosed in 12, diffuse in 8, mixed and indeterminate type in two cases (according to Lauren). Methods: Gastric mucosa samples (altogether up to 15) from the each operation specimen were stained with haematoxylin and eosin. Tissue material was received from the primary tumour and the tumour surrounding antral and corpus mucosa. The stage of atrophy by OLGA was established by combining the extent of histologically scored atrophy with the topography of atrophy. IgG antibodies to H. pylori cell surface proteins and CagA were evaluated using ELISA. Results: Of the 12 patients with intestinal type of gastric cancer eight had OLGA stage III or IV, four had OLGA stage II and nobody had OLGA stage I (p < .05). Five patients with diffuse cancer had OLGA stage I and II, two had III stage and one had IV stage. There was no association of OLGA stage or cancer type with CagA positivity. Conclusion: Gastric cancer patients represented all stages of gastric atrophy from OLGA stage I to OLGA stage IV which was not associated with cancer type and CagA seropositivity. a 2011 Blackwell Publishing Ltd, Helicobacter 16 (Suppl. 1): 77–143 79 WS1 Gastric Cancer

Characterization of new human gastric epithelial cell lines

no.: WS1.1 HELICOBACTER PYLORI INFECTION AND MARKERS OF GASTRIC CANCER RISK IN ALASKA NATIVE PEOPLE J. Keck,* K. Miernyk,* L. Bulkow,* J. Kelly, B. McMahon, F. Sacco, T. Hennessy* and M. G. Bruce* *Centers for Disease Control and Prevention, Anchorage, AK, USA; Alaska Native Tribal Health Consortium, Anchorage, AK, USA Background: Alaska Native gastric cancer incidence and mortality rates are 3 to 4-times higher than general US population rates. We evaluated pepsinogen I, pepsinogen I/II ratio, anti-H. pylori and CagA antibodies, and blood group to determine their association with gastric cancer development in Alaska Native people. Methods: We conducted a retrospective case-control study that matched gastric cancers reported to the Alaska Native Tumor Registry from 1969–2008 to three controls on known demographic risk factors for H. pylori infection, using previously collected sera from the Alaska Area Specimen Bank. Conditional logistic regression evaluated the associations between serum markers and gastric cancer. Results: We included 122 gastric cancer cases with sera predating cancer diagnosis (mean = 13 years) and 346 matched controls. One hundred and twelve cases (91.8%) and 285 controls (82.4%) had evidence of previous or ongoing H. pylori infection as measured by anti-H. pylori antibodies. Gastric cancer cases had 2.63-fold increased odds of positive anti-H. pylori antibodies compared with their matched controls (p = .01). In a multivariate model, non-cardia gastric cancer (n = 94) was associated with anti-H. pylori antibodies (adjusted OR 3.92, p = .004) and low pepsinogen I (aOR 6.04, p = .04). We found no association between gastric cancer and blood group, anti-CagA antibodies, or pepsinogen I/II ratio. Conclusions: Alaska Native people with gastric cancer had increased odds of previous H. pylori infection. Low pepsinogen I might function as a pre-cancer marker for non-cardia cancer. Impact: Future research to identify Alaska Native individuals with increased gastric cancer risk includes H. pylori genotype and host characteristic studies. Abstract no.: WS1.2 CLUSTERING OF HELICOBACTER PYLORI STRAINS FROM GASTRIC CANCER C. Wang, S. Zhan and Q. Dong Qingdao Municipal Hospital, Qingdao City, Chinano.: WS1.2 CLUSTERING OF HELICOBACTER PYLORI STRAINS FROM GASTRIC CANCER C. Wang, S. Zhan and Q. Dong Qingdao Municipal Hospital, Qingdao City, China Genetic differences between strains play an important role in the determination of clinical outcomes of Helicobacter pylori infection. This study aimed to determine the sequencing types of H. pylori strains from gastric cancer. Materials and Methods: Twenty-two strains of H. pylori were enrolled, including 12 strains from patients with gastric cancer. MLST was used to determine the sequencing type. Results: The seven genetic loci of H. pylori were PCR amplified and sequenced. Those sequences of the seven genes were concatenated, and aligned with the sequences of strains from Europe (5), Africa (5), Asia (5) and other parts of China (16) extracted from the MLST database. A neighbour-joining tree with a kimura 2-parameter model was subsequently constructed. The results showed that all 22 strains, as well as Asia strains from database fell into the HpEastAsia haplogroup which could divided into two groups, groups I and II. Group I consisted of seven cancer strains but only one non-cancer strain of H. pylori, in addition to five strains form database. Fisher’s exact test revealed a statistically significant difference (p = .027). Discussion and Conclusion: The clustering of cancer strains of H. pylori is consistent with a recent report showing that the phylogeopraphic origin of H. pylori is a determinant of gastric cancer risk. This may reflect the consequence of long-term interaction of the bacterium with individual hosts of different genetic ground. The results suggested that the sequencing types could possibly be used to predict the clinical outcomes of H. pylori infection. Abstract no.: WS1.3 LACK OF ASSOCIATION BETWEEN GENE POLYMORPHISMS OF ANGIOTENSIN CONVERTING ENZYME, NOD-LIKE RECEPTOR 1, TOLL-LIKE RECEPTOR 4 AND FAS/FASL WITH THE PRESENCE OF HELICOBACTER PYLORI-INDUCED PREMALIGNANT GASTRIC LESIONS AND GASTRIC CANCER IN CAUCASIANS J. Kupcinskas,* T. Wex, J. Bornschein, M. Selgrad, M. Leja, L. Jonaitis* and P. Malfertheiner *Department of Gastroenterology, Lithuanian University of Health Sciences, Kaunas, Lithuania; Clinic of Gastroenterology, Hepatology and Infectious Diseases, Otto von Guericke University, Magdeburg, Germany; Faculty of Medicine, University of Latvia, Digestive Diseases Center, Hospital Lizeners, Riga, Latvia Background: Several polymorphisms of genes involved in the immunological recognition of Helicobacter pylori and regulating apoptosis and proliferation have been linked to gastric carcinogenesis, however reported data are partially conflicting. The aim of our study was to evaluate potential associations between the presence of gastric cancer (GC) and high risk atrophic gastritis (HRAG) and polymorphisms of genes encoding Angiotensin converting enzyme (ACE), Nod-like receptor 1 (NOD1), Toll-like receptor 4 (TLR4) and FAS/FASL. Methods: Gene polymorphisms were analyzed in 574 subjects (GC: n = 114; HRAG: n = 222, controls: n = 238) of Caucasian origin. ACE I/D (rs4646994), NOD1 796G>A (rs5743336), TLR4 3725G>C (rs11536889), FAS 1377G>A (rs2234767), FAS 670A>G (rs1800682) and FASL 844T>C (rs763110) were genotyped by different PCR approaches and RFLP analysis. Results: Frequencies of genotypes in our study are similar to the data reported on subjects of Caucasian ethnicity. There was a tendency for NOD1 796G/G genotype to be associated with increased risk of HRAG (62.4% vs 54.5% in controls, p = .082). FAS 670G/G genotype was more frequent in HRAG when compared to controls, 23.9% and 17.2% respectively, however it failed to reach significance level (p = .077). We did not find any significant associations for all examined polymorphism in relation to GC or HRAG. NOD1 796G>A and TLR4 3725G>C gene polymorphisms were also not linked with Helicobacter pylori seropositivity status. Conclusions: ACE, NOD1, TRL4 and FAS/FASL gene polymorphisms are not linked with gastric carcinogenesis in Caucasians, and therefore they should not be considered as potential biomarkers for identifying individuals with higher risk for GC. Abstract no.: WS1.4 ATROPHIC GASTRITIS BY THE OLGA STAGES AND HELICOBACTER CAGA SEROPOSITIVITY IN GASTRIC CANCER T. Vorobjova,* K. Kull,* H. Saar,* R. Labotkin,* A. Zimmermann and H. Maaroos* *University of Tartu, Tartu, Estonia; University of Bern, Bern, Switzerlandno.: WS1.4 ATROPHIC GASTRITIS BY THE OLGA STAGES AND HELICOBACTER CAGA SEROPOSITIVITY IN GASTRIC CANCER T. Vorobjova,* K. Kull,* H. Saar,* R. Labotkin,* A. Zimmermann and H. Maaroos* *University of Tartu, Tartu, Estonia; University of Bern, Bern, Switzerland Introduction: Operative Link on Gastritis Assessment (OLGA) express extent of gastric atrophy in terms of gastritis staging, which severity should be related to gastric cancer. Aim: To study how the OLGA stages of atrophic gastritis are associated with the morphological type, and Helicobacter pylori CagA positivity in gastric cancer. Patients: Twenty two gastric carcinoma patients (8 male, 14 female; mean age 64 ± 12) were operated on. The intestinal type of carcinoma was diagnosed in 12, diffuse in 8, mixed and indeterminate type in two cases (according to Lauren). Methods: Gastric mucosa samples (altogether up to 15) from the each operation specimen were stained with haematoxylin and eosin. Tissue material was received from the primary tumour and the tumour surrounding antral and corpus mucosa. The stage of atrophy by OLGA was established by combining the extent of histologically scored atrophy with the topography of atrophy. IgG antibodies to H. pylori cell surface proteins and CagA were evaluated using ELISA. Results: Of the 12 patients with intestinal type of gastric cancer eight had OLGA stage III or IV, four had OLGA stage II and nobody had OLGA stage I (p < .05). Five patients with diffuse cancer had OLGA stage I and II, two had III stage and one had IV stage. There was no association of OLGA stage or cancer type with CagA positivity. Conclusion: Gastric cancer patients represented all stages of gastric atrophy from OLGA stage I to OLGA stage IV which was not associated with cancer type and CagA seropositivity. a 2011 Blackwell Publishing Ltd, Helicobacter 16 (Suppl. 1): 77–143 79 WS1 Gastric Cancer