The OLGA-OLGIM staging and the interobserver agreement for gastritis and preneoplastic lesion screening: a cross-sectional study.

Stomach cancer (SC) incidence and mortality are relevant public health issues worldwide. In Colombia, screening for preneoplastic lesions (PNL) and the presence of H. pylori is not routinely performed. Therefore, the aim of this study was to evaluate OLGA-OLGIM staging and the interobserver agreement in gastritis and preneoplastic lesions in patients with gastroduodenal symptoms from Colombia. A cross-sectional study was conducted in 272 patients with gastroduodenal symptoms. Gastric biopsies were taken following the Updated Sydney System with the OLGA-OLGIM classification, and the results were evaluated by two pathologists. Chronic gastritis and PNL were reported in 76% and 24% of the patients, respectively. Furthermore, 25% of the patients with PNL displayed gastric atrophy (GA) and 75% intestinal metaplasia (IM). Agreement in the histopathological reading for IM was good, whereas for OLGA was variable, and for the H. pylori quantity was poor. OLGA-OLGIM stages 0-II were the most frequent (96%), while stage III (4%) and SC (4%) were the least frequent. Age and coffee consumption were associated with a higher prevalence of PNL. This work determined that 4% of the population is at high risk of developing SC and would benefit from follow-up studies. Reinforcement of training programs to improve the agreement in histopathology readings is required.

Genetic polymorphisms in the cag pathogenicity island of Helicobacter pylori and risk of stomach cancer and high-grade premalignant gastric lesions.

Helicobacter pylori (Hp) infects the stomach of about half of the human population and is strongly associated with the risk of gastric cancer (GC) and its premalignant precursors. The cag pathogenicity island (cagPAI) is a region of the Hp genome encoding for key molecular machinery involved in the infection process. Following a sequencing study, we selected 50 genetic polymorphisms located in seven cagPAI genes and tested their associations with the risk of advanced gastric premalignant lesions and GC in 1220 subjects from various Latin American populations showing the whole spectrum of phenotypes from gastritis to GC. We found that three polymorphisms of cagA are associated with the risk of advanced gastric premalignant lesions (incomplete intestinal metaplasia [ie, Type 2 and 3] or dysplasia), and that six polymorphisms located in cagA, cagL and cagI were associated with risk of GC. When corrected for multiple testing none of the associations were statistically significant. However, scores built by integrating the individual polymorphisms were significantly associated with the risk of advanced gastric premalignant lesions and GC. These results have the potential of establishing markers for risk stratification in the general population, in view of targeting Hp eradication to high-risk population groups.

Risk factors for gastric precancerous and cancers lesions in Latin American counties with difference gastric cancer risk.

OBJECTIVE: To evaluate the risk factors associated with pre-neoplastic lesions and gastric cancer in countries with different cancer risk in Latin America. METHODS: 1222 questionnaires of risk factors related to pre-neoplastic lesions and gastric cancer were obtained from patients from Mexico (N = 559), Colombia (N = 461) and Paraguay (N = 202), who were treated at the gastroenterology or oncology service of participant hospitals. In addition, biopsies specimens to establish histological diagnosis and blood to detect IgG antibodies against Helicobacter-pylori (H. pylori) whole-cell antigens and CagA protein using an ELISA were collected. These consisted of 205 gastric cancer, 379 pre-neoplastic (intestinal metaplasia (IM) / atrophic gastritis) and 638 control (normal /non-atrophic gastritis) cases. The odds ratio (OR) and 95% confidence intervals (CI) associated with potential risk factors were estimated by polynomial logistic regression model. RESULTS: Seropositivity to H. pylori was associated with risk of pre-neoplastic lesions, with OR = 1.9 (CI 95% 1.2-2.9; p = 0.006). Grain / cereal intake (OR = 1.6, 95% CI 1.0-2.5 ; p = 0.049) and egg intake (OR = 1.7 95% CI 1.1-2.6 ; p = 0.021) were related to gastric cancer. Among, people who did not developed gastric cancer, smoking more than five cigarette per day had the highest risk of being infected by H. pylori (OR = 1.9; CI 95% 1.1-3.3 ; p = 0.028). CONCLUSION: The present study in Latin American countries confirmed that similar environmental factors such as smoking and grain/cereal consumption were associated with H. pylori infection and its induced gastric lesions as reported in other regions where dominant H. pylori strains differ.

Rapid evolution of the Helicobacter pylori AlpA adhesin in a high gastric cancer risk region from Colombia.

To be able to survive, Helicobacter pylori must adhere to the gastric epithelial cells of its human host. For this purpose, the bacterium employs an array of adhesins, for example, AlpA. The adhesin AlpA has been proposed as a major adhesin because of its critical role in human stomach colonization. Therefore, understanding how AlpA evolved could be important for the development of new diagnostic strategies. However, the genetic variation and microevolutionary patterns of alpA have not been described in Colombia. The study aim was to describe the variation patterns and microevolutionary process of alpA in Colombian clinical isolates of H. pylori. The existing polymorphisms, which are deviations from the neutral model of molecular evolution, and the genetic differentiation of the alpA gene from Colombian clinical isolates of H. pylori were determined. The analysis shows that gene conversion and purifying selection have shaped the evolution of three different variants of alpA in Colombia.

Integration, Viral Charge and E2 mRNA Levels in the Progresion of Intraepitelial Cervical Lesions / Integración, carga viral y niveles de arn mensajero de e2 de vph 16 en la progresión de lesiones intraepiteliales cervicales

RESUMEN Entre las lesiones intraepiteliales escamosas cervicales (LIE) es importante distinguir aquellas asociadas con mayor riesgo de cáncer de cuello uterino. El objetivo de este trabajo fue evaluar si los niveles de expresión de E2 del VPH16 en mujeres con LIE y con evidencia de integración viral se asocian con el grado de la lesión. Se analizaron 109 cepillados cervicales positivos para VPH 16 provenientes de 19 mujeres sin LIE, 45 mujeres con LIE de bajo grado (LIEBG) y 45 mujeres con LIE de alto grado (LIEAG). Se cuantificó el número de copias de ARNm de E2 y de los genes E2 y E6 mediante PCR en tiempo real para determinar la carga viral (E6) y la proporción E2/E6 para evaluar la integración viral. Se encontraron frecuencias similares de expresión de E2 en LEIBG y LEIAG 15/45 (33 %), la frecuencia en mujeres sin lesión fue menor 3/19 (15,8 %), todos los casos en los que se observó expresión del gen E2 tenían mezcla de ADN viral episomal e integrado. La carga viral aumentó significativamente a mayor grado de la lesión (ρ =0,049), mientras que la proporción E2/E6 disminuyó (ρ=0,049). El análisis ROC mostró una baja capacidad de los tres parámetros virales para distinguir entre lesiones de bajo y alto grado. En conclusión, aunque las lesiones con presencia de ADN viral mixto e integrado y expresión de E2 podrían estar en menor riesgo de progresión, y la carga viral y la integración se relacionaron con mayor gravedad de la lesión, su valor clínico como biomarcadores de LEIAG es limitado.

ABSTRACT It is important to distinguish among squamous intraepithelial lesions (SIL) those associated with increased risk cervical cancer. Our aim was to evaluate if the expression level of gen E2 in women with SIL and evidence of viral integration is associated to the grade of lesion. Cervical scrapes HPV16 positive from 19 women with normal histology, 45 women with low-grade SIL (LSIL) and 45 women with high-grade SIL (HSIL) were analyzed. Real-time PCR was used to quantify the mRNA of E2 and E2 and E6 genes to calculate viral load (E6) and the ratio E2/E6 to assess viral integration. Similar frequencies of E2 expression were found in LSIL and HSIL15/45 (33 %), the frequency in women without SIL was lower 3/19 (15.8 %), and all cases with E2 gene expression had mixed episomal and integrated viral DNA. The viral load increased significantly with the grade of SIL (ρ= 0.049), while E2/E6 ratio decreased (ρ=0.049). The ROC analysis showed low capacity of the three viral parameters analyzed to distinguish between low and high grade SIL. In conclusion although SIL with mixed and integrated viral DNA with E2 expression could be at lower risk of progression, and viral load and integration were associated with higher severity of the lesion, its clinical value as biomarkers of HSIL is limited.

Phylogenomics of Colombian Helicobacter pylori isolates.

BACKGROUND: During the Spanish colonisation of South America, African slaves and Europeans arrived in the continent with their corresponding load of pathogens, including Helicobacter pylori. Colombian strains have been clustered with the hpEurope population and with the hspWestAfrica subpopulation in multilocus sequence typing (MLST) studies. However, ancestry studies have revealed the presence of population components specific to H. pylori in Colombia. The aim of this study was to perform a thorough phylogenomic analysis to describe the evolution of the Colombian urban H. pylori isolates. RESULTS: A total of 115 genomes of H. pylori were sequenced with Illumina technology from H. pylori isolates obtained in Colombia in a region of high risk for gastric cancer. The genomes were assembled, annotated and underwent phylogenomic analysis with 36 reference strains. Additionally, population differentiation analyses were performed for two bacterial genes. The phylogenetic tree revealed clustering of the Colombian strains with hspWestAfrica and hpEurope, along with three clades formed exclusively by Colombian strains, suggesting the presence of independent evolutionary lines for Colombia. Additionally, the nucleotide diversity of horB and vacA genes from Colombian isolates was lower than in the reference strains and showed a significant genetic differentiation supporting the hypothesis of independent clades with recent evolution. CONCLUSIONS: The presence of specific lineages suggest the existence of an hspColombia subtype that emerged from a small and relatively isolated ancestral population that accompanied crossbreeding of human population in Colombia.

Clinical manifestations of colorectal cancer patients from a large multicenter study in Colombia.

Colorectal cancer (CRC) is a major public health problem, and its incidence is rising in developing countries. However, studies characterizing CRC clinicopathological features in cases from developing countries are still lacking. The goal of this study was to evaluate clinicopathological and demographic features in one of the largest CRC studies in Latin America.The study involved over 1525 CRC cases recruited in a multicenter study in Colombia between 2005 and 2014 as part of ongoing genetic and epidemiological studies. We gathered clinicopathological data such as age at diagnosis, sex, body mass index, tobacco and alcohol consumption, family history of cancer, and tumor features including location, histological type, and stage. Statistical analyses were performed to test the association between age of onset, sex, and clinical manifestations.The average age at CRC diagnosis was 57.4 years, with 26.5% of cases having early-onset CRC (diagnosed by age 50 years). Most cases were women (53.2%; P = 0.009), 49.2% were overweight or obese, 49.1% were regular alcohol drinkers, 52% were smokers/former smokers, and 12.2% reported relatives with cancer. Most tumors in the study were located in the rectum (42.7%), were adenocarcinomas (91.5%), and had advanced stage (T3-T4, 79.8%). Comparisons by sex found that male cases were more likely to be obese (36.5% vs 31.1%; P = 0.001), less likely to have a family history of cancer (9.7% vs 15.3%; P = 0.016), and more likely to have advanced-stage tumors (83.9% vs 76.1%; P = 0.036). Comparisons by age of onset found that early-onset cases were more likely to be women (59.3% vs 51.0%; P = 0.005) and report a family history of cancer (17.4% vs 10.2%; P = 0.001).To our knowledge, our study is the largest report of clinicopathological characterization of Hispanic CRC cases, and we suggest that further studies are needed to understand CRC etiology in diverse Hispanic populations.

Distribución de los genotipos del virus del papiloma humano en mujeres de Bogotá con anomalías en la citología cervicouterina / Genotype distribution of Human Papillomavirus in women from Bogotá with abnormal cervical smear

Objetivos: Determinar la distribución de los genotipos de VPH en mujeres de Bogotá con citología cervicouterina anormal. Métodos: Se colectaron muestras cervicales de 191 mujeres con ASCUS, 236 con lesiones intraepiteliales escamosas de bajo grado (LIEBG) y 116 de alto grado (LIEAG). La tipificación de VPH se realizó usando PCR con iniciadores consenso GP5+/GP6+ y reverse line blot. Resultados: La prevalencia de VPH fue 76,1%. Se observaron infecciones únicas en el 41,4% de las participantes, y coinfecciones en el 34,6%. La frecuencia de VPH según diagnóstico fue: 60,2%, 84,7% y 84,5% en ASCUS, LIEBG y LIEAG. Los VPH-16 y 58 fueron los tipos más frecuentes en los tres grupos, con frecuencias para VPH-16 de 20,4%, 33,9% y 38,8%, y para VPH-58 de 7,3%, 13,6%, 18,1% para ASCUS, LIEBG y LIEAG. En ASCUS y LSIL el tercer tipo en frecuencia fue VPH-56 (6,8% y 11,0%), mientras que en LIEAG fue VPH-18 (10,3%). Las infecciones con tipos virales probablemente oncogénicos y con tipos de bajo riesgo fueron mucho menos frecuentes y en general se presentaron como coinfecciones con tipos de alto riesgo. Conclusiones: Las infecciones con tipos de VPH de alto riesgo fueron las más frecuentes en todas las lesiones estudiadas, el VPH-58 ocupo el segundo lugar en frecuencia, como ha sido reportado en México y en general en Suramérica. El cambio hacia nuevas vacunas profilácticas que incluyan más tipos virales como el VPH-58 puede tener un mayor impacto en la disminución de la incidencia de lesiones preneoplásicas en nuestra región.

Objective: To determine the distribution of HPV genotypes in women from Bogotá with abnormal cervical smear. Methods: Cervical samples were collected from 191 women with ASCUS, 236 with low-grade (LSIL) and 116 with high-grade squamous intraepithelial lesions (HSIL). HPV typing was performed using consensus PCR primers GP5+/GP6 + and reverse line blot. Results: The prevalence of HPV was 76.1%. Unique infections were observed in 41.4% of the participants and co-infections in 34.6%. The frequency of HPV according to diagnosis was: 60.2%, 84.7% and 84.5% in ASCUS, LSIL and HSIL respectively. HPV16 and 58 were the more frequent types in the three groups, HPV16 frequencies were 20.4%, 33.9% and 38.8%, and HPV58 frequencies were 7.3%, 13.6%, and 18,1% for ASCUS, LSIL and HSIL respectively. The third type in frequency in ASCUS and LSIL was HPV56 (6.8% and 11.0%), while in HSIL was HPV18 (10.3%). Infections with probably oncogenic types or with low risk types were much less frequent and generally were observed as co-infections with high-risk types. Conclusions: Infections with high risk HPV types were the most frequent in all studied lesions, VPH-58 ranked second in frequency as has been reported in Mexico and in general in South America. The change to new prophylactic vaccines including more viral types as HPV58 could have a higher impact in reducing the incidence of pre-neoplastic lesions in our region.

Draft Genome Sequence of a Helicobacter pylori Strain Isolated from a Patient with Diffuse Gastritis from a Region of High Cancer Risk in Colombia.

The draft genome sequence of one Colombian Helicobacter pylori strain is presented. This strain was isolated from a patient with diffuse gastritis from Tibaná, Boyacá, a region with high gastric cancer risk.

[Genotyping of Helicobacter pylori virulence factors vacA and cagA in individuals from two regions in Colombia with opposing risk for gastric cancer]. / Genotipificación de los factores de virulencia vacA y cagA de Helicobacter pylori en individuos de dos regiones de Colombia con riesgo opuesto de cáncer gástrico.

INTRODUCTION: The overall prevalence of Helicobacter pylori infection is high in Colombia; however, in the country´s Andean region, gastric cancer rates far surpass those in coastal areas. Helicobacter pylori genotypes cagA positive and vacA s1 and m1 are associated with an increased risk of gastric cancer. OBJECTIVE: To compare the distribution of H. pylori genotypes associated with virulence in two regions in Colombia with opposing risk for gastric cancer. MATERIALS AND METHODS: Four hundred and one gastric antral biopsies were obtained and analyzed from 401 individuals diagnosed with non-atrophic gastritis, atrophic gastritis and intestinal metaplasia: 256 came from the high-risk area cities of Tunja and Bogotá, and 145 from the low-risk area cities of Barranquilla, Santa Marta and Cartagena. Genotyping of virulence genes vacA and cagA was performed by PCR. RESULTS: No difference was observed in the frequency of H. pylori infection between the two areas (77.3% vs 77.9 %, p=non significant, ns). The presence of cagA was higher in the low-risk area (77.9% vs. 69.2 %, p=ns). The vacA s1 allele was also more prevalent in the low-risk area (61.8 % vs 72.0 %, p=ns). The vacA m1 allele was more prevalent in the high-risk area (57.2 % vs 42.8 %, p=ns). The cagA positive s1m1 combination was also more frequent in the low-risk area (48.9% vs 38.9%, p=ns). CONCLUSIONS: The differences in the risk of gastric cancer in these two geographic areas cannot be explained by differences in the prevalence of infection by H. pylori or by differences in the virulence of circulating strains.

Genotipificación de los factores de virulencia vacA y cagA de Helicobacter pylori en individuos de dos regiones de Colombia con riesgo opuesto de cáncer gástrico / Genotyping of Helicobacter pylori virulence factors vacA and cagA in individuals from two regions in Colombia with opposing risk for gastric cancer

Introducción. La prevalencia de infección por Helicobacter pylori es alta en Colombia; en la zona andina las tasas de cáncer gástrico son altas mientras que en las zonas costeras son bajas. Los genotipos de H. pylori cagA positivo y vacA s1 y m1 se asocian con un mayor riesgo de cáncer gástrico. Objetivo. Determinar las diferencias en las frecuencias de los genotipos de H. pylori asociados a virulencia en dos regiones de Colombia con riesgo opuesto de cáncer gástrico. Materiales y métodos. Se analizaron 401 biopsias del antro gástrico provenientes de 401 individuos con diagnóstico de gastritis no atrófica, gastritis atrófica o metaplasia intestinal; 256 se obtuvieron en la zona de alto riesgo (Tunja y Bogotá) y, 145, en la zona de bajo riesgo (Barranquilla, Santa Marta y Cartagena). La genotipificación de los genes de virulencia cagA y vacA se hizo mediante reacción en cadena de la polimerasa (PCR). Resultados. No se observó diferencia en la frecuencia de infección por H. pylori entre las dos zonas (77,3 Vs . 77,9 %, p=no significativo, ns). La presencia de cagA fue mayor en la zona de bajo riesgo (77,9 Vs . 69,2 %, p=ns). El alelo vacA s1 también fue más prevalente en la zona de bajo riesgo (61,8 Vs . 72,0 %, p=ns). El alelo vacA m1 presentó mayor prevalencia en la zona de alto riesgo (57,2 Vs . 42,8 %, p=ns). La combinación cagA positivo s1m1 también fue más frecuente en la zona de bajo riesgo (48,9 Vs . 38,9 %, p=ns). Conclusiones. Las diferencias en el riesgo de cáncer gástrico en estas dos zonas no pueden explicarse por las diferencias en la prevalencia de infección por H. pylori o en la virulencia de las cepas circulantes.

Introduction: The overall prevalence of Helicobacter pylori infection is high in Colombia; however, in the country´s Andean region, gastric cancer rates far surpass those in coastal areas. Helicobacter pylori genotypes cagA positive and vacA s1 and m1 are associated with an increased risk of gastric cancer. Objective: To compare the distribution of H. pylori genotypes associated with virulence in two regions in Colombia with opposing risk for gastric cancer. Materials and methods: Four hundred and one gastric antral biopsies were obtained and analyzed from 401 individuals diagnosed with non-atrophic gastritis, atrophic gastritis and intestinal metaplasia: 256 came from the high-risk area cities of Tunja and Bogotá, and 145 from the low-risk area cities of Barranquilla, Santa Marta and Cartagena. Genotyping of virulence genes vacA and cagA was performed by PCR. Results: No difference was observed in the frequency of H. pylori infection between the two areas (77.3% vs 77.9 %, p=non significant, ns). The presence of cagA was higher in the low-risk area (77.9% vs. 69.2 %, p=ns). The vacA s1 allele was also more prevalent in the low-risk area (61.8 % vs 72.0 %, p=ns). The vacA m1 allele was more prevalent in the high-risk area (57.2 % vs 42.8 %, p=ns). The cagA positive s1m1 combination was also more frequent in the low-risk area (48.9% vs 38.9%, p=ns). Conclusions: The differences in the risk of gastric cancer in these two geographic areas cannot be explained by differences in the prevalence of infection by H. pylori or by differences in the virulence of circulating strains.

Niveles séricos de pepsinógeno y su capacidad diagnóstica de atrofia gástrica en diferentes poblaciones colombianas / Serum pepsinogen levels and gastric atrophy diagnostic capacity in different Colombian populations

Objetivo: Caracterizar los niveles de pepsinógeno y evaluar la capacidad de discriminación del PGI y la relación PGI/PGII para el diagnóstico serológico de atrofia gástrica en diferentes poblaciones colombianas. Materiales y métodos: Participaron 600 sujetos sin sintomatología gástrica y se analizaron 544 muestras de pacientes con sintomatología gástrica provenientes de diferentes poblaciones con riesgos opuestos para cáncer gástrico. A todos los participantes se les tomó muestra de sangre. En los pacientes se obtuvieron biopsias de antro y cuerpo para su diagnóstico inicial de lesiones gastroduodenales. Los niveles de pepsinógeno y la serología de Helicobacter pylori se estimaron con pruebas de ELISA. Los análisis estadísticos incluyeron pruebas de Kruskal-Wallis y Mann-Whitney, curva ROC y valores diagnósticos. Resultados: Los niveles de pepsinógeno en pacientes y sujetos asintomáticos difieren según la zona de riesgo de procedencia. Los niveles de PGI, PGII y PGI/PGII disminuyeron a medida que aumenta la severidad del diagnóstico histológico (p < 0,005), al igual que con el grado de severidad de la atrofia y la localización multifocal (p≤0,001). El PGI ≤86,68 y PGI/PGII ≤3,19 con un área bajo la curva de 0,76 identificó pacientes con atrofia severa multifocal, serología positiva para H. pylori y procedentes de la zona de riesgo alto, con sensibilidad de 77,5% y especificidad de 71,74%. Conclusión: Los resultados sugieren que los niveles de PGI, PGI/PGII conjuntamente con serología H. pylori positiva podrían ser considerados para la detección de atrofia severa en pacientes de la zona de riesgo alto. Se necesita otros estudios en poblaciones de riesgo alto.

Objective: To characterize levels of pepsinogen and evaluate the discrimination ability of pepsinogen I (PGI) and the PGI/ pepsinogen II (PGII) ratio for the serological diagnosis of gastric atrophy in different Colombian populations. Methods: A total 600 subjects without gastric symptoms participated and 544 samples from patients with gastric symptomatology were analyzed from different populations with opposing risks to gastric cancer. A blood sample was taken from all participants; a gastric antrum and body biopsy for the initial diagnosis of gastroduodenal lesions was obtained from the patients. The levels of pepsinogen and Helicobacter pylori serology were estimated with ELISA. Statistical analyses included Kruskal -Wallis and Mann -Whitney test, ROC curve and diagnostic values. Results: The levels of PGI and PGI / PGII differ by risk area of origin. Levels of PGI, PGII and PGI / PGII decreased with increasing severity of histological diagnosis (P < .005), as with the severity of atrophy and multifocal localization (P ≤.001). The PGI ≤ 86.68 and PGI / PGII ≤ 3.19 with an area under the curve of 0.76 identified patients with severe multifocal atrophy, positive serology for H. pylori, and from the high risk area, with a sensitivity of 77.5% and specificity of 71.74%. Conclusion: The results suggest that PGI levels together with PGI / PGII ratios and positive serology for H. pylori could be considered for the detection of severe atrophy in high-risk areas. Further studies are needed in high-risk populations © 2014 Instituto Nacional de Cancerología. Published by Elsevier España, S.L.U. All rights reserved.

Lesiones preneoplásicas gástricas en pacientes colombianos: asociación de polimorfismos genéticos interleucinas 1B-511, 1RN, 10-819, 10-1082, factor de necrosis tumoral-&alpha -308 y anticuerpos inmunoglobulina G hacia cagA de Helicobacter pylori / Pre-cancerous gastric lesions in Colombian patients: association with IL-1B-511, IL-1RN, IL-10-919, IL-10-1082, TNF-&alpha -308 genes polymorphisms, and anti-Helicobacter pylori cagA IgG antibodies

Objetivo: Evaluar la asociación de los polimorfismos de alguna de las citocinas más estudiadas en relación con el cáncer gástrico (IL-1B-511, IL-1RN intron-2-VNTR, TNF-α-308, IL-10-819 e IL-10- 1082) y la presencia de anticuerpos hacia la proteína cagA de Helicobacter pylori con las lesiones preneoplásicas gástricas en pacientes colombianos. Materiales y métodos: Se estudiaron 185 pacientes con lesiones preneoplásicas (gastritis atrófca, metaplasia intestinal y displasia), y 154 controles (gastritis no atrófica), provenientes de hospitales de una zona de riesgo alto y otra de riesgo bajo para cáncer gástrico. Se obtuvieron biopsias gástricas y muestras de sangre; la genotipificación de los polimorfismos se hizo por discriminación alélica usando PCR en tiempo real y por PCR convencional y electroforesis en agarosa (VNTR del intron 2 de IL-1RN); la serología de Helicobacter pylori y Helicobacter pylori cagA se determinó por ELISA. Se utilizó regresión logística multinomial en el análisis estadístico. Resultados: El genotipo IL-1B-511TT (odds ratio = 4,05; intervalo de confianza 95% 1,35-12,10) se asoció a metaplasia intestinal; no se observaron otras asociaciones entre los diferentes polimorfismos y las lesiones preneoplásicas. La infección por Helicobacter pylori cagA positivo se asoció a gastritis atrófica, metaplasia intestinal y displasia (OR = 2,66; 13,70; 40,29, respectivamente). Conclusión: Los resultados sugieren que entre los genotipos proinflamatorios el genotipo IL-1B-511TT estaría asociado a la metaplasia intestinal, y la serología de Helicobacter pylori cagA positivo sería un biomarcador útil para intervenir y prevenir la presencia de lesiones preneoplásicas. Se necesitan otros estudios con población colombiana que evalúen la asociación hallada de IL1B-511 con la metaplasia intestinal.

Objective: To evaluate the relationship of some of the most studied cytokines (IL-1B-511, IL-1RN intron-2-VNTR, TNF-a-308, IL-10-819, and IL-10-1082) with gastric cancer, as well as the presence of anti-Helicobacter pylori cagA IgG antibodies with pre-cancerous lesions in Colombian patients. Materials and methods: A study was conducted on 185 patients with pre-cancerous lesions (atrophic gastritis, intestinal metaplasia and dysplasia), and 154 controls (non-atrophic gastritis), seen in hospitals in a high risk area, and another in a low risk area, for gastric cancer. Gastric biopsy specimens and blood samples were obtained. The genotyping of the polymorphisms was performed by allelic discrimination using real-time PCR, conventional PCR, and agarose electrophoresis (VNTR of IL-1RN intron 2). The serology of Helicobacter pylori and Helicobacter pylori cagA was determined by ELISA. A multinomial logistic regression was used in the statistical analysis. Results: The IL-1B-511TT genotype was associated with intestinal metaplasia (OR=4.05; 95% CI; 1.35-12.10). No other relationships were observed between the different polymorphisms and preimg/revistas/rcc/cancerous lesions. Infection due to a positive Helicobacter pylori cagA was associated with atrophic gastritis, intestinal metaplasia and dysplasia (OR=2.66; 13.70; 40.29, respectively). Conclusion: The results suggest that, among the pro-inflammatory genotypes, the IL-1B-511TT would be associated with intestinal metaplasia, and that a positive Helicobacter pylori cagA serology could be a useful biomarker for the intervention and prevention of pre-cancerous lesions. Further studies are required in the Colombian population in order to evaluate the relationship found between IL1B-511 and intestinal metaplasia.

CagA EPIYA polymorphisms in Colombian Helicobacter pylori strains and their influence on disease-associated cellular responses.

AIM: To investigate the influence of the CagA diversity in Helicobacter pylori (H. pylori) strains from Colombia on the host cell biology. METHODS: Eighty-four H. pylori-cagA positive strains with different Glu-Pro-Ile-Tyr-Ala (EPIYA) motifs patterns, isolated from patients with gastritis (n = 17), atrophic gastritis (n = 17), duodenal ulcer (n = 16), intestinal metaplasia (n = 16) and gastric cancer (n = 18), were included. To determine the integrity of the cag pathogenicity island (cagPAI) we evaluated the presence of cagA, cagT, cagE, and cag10 genes by polymerase chain reaction. AGS gastric epithelial cells were infected with each strain and assayed for translocation and tyrosine phosphorylation of CagA by western blot, secretion of interleukin-8 (IL-8) by enzyme-linked immuno sorbent assay after taking supernatants from cocultures and cell elongation induction. For cell elongation quantification, coculture photographs were taken and the proportion of "hummingbird" cells (> 15 µm) was determined. RESULTS: Overall 72% (60/84) of the strains were found to harbor a functional cagPAI. Levels of phosphorylated CagA were significantly higher for isolates from duodenal ulcer than the ones in strains from gastritis, atrophic gastritis, intestinal metaplasia and gastric cancer (49.1% ± 23.1% vs 21.1% ± 19.5%, P < 0.02; 49.1% ± 23.1% vs 26.2% ± 14.8%, P < 0.045; 49.1% ± 23.1% vs 21.5% ± 19.5%, P < 0.043 and 49.1% ± 23.1% vs 29.5% ± 27.1%, P < 0.047 respectively). We observed variable IL-8 expression levels ranging from 0 to 810 pg/mL and from 8.8 to 1442 pg/mL at 6 h and 30 h post-infection, respectively. cagPAI-defective strains did not induce detectable levels of IL-8 at 6 h post-infection. At 30 h post-infection all strains induced IL-8 expression in AGS cells, although cagPAI-defective strains induced significantly lower levels of IL-8 than strains with a functional cagPAI (57.1 ± 56.6 pg/mL vs 513.6 ± 338.6 pg/mL, P < 0.0001). We did not observe differences in the extent of cell elongation induction between strains with a functional or a defective cagPAI in 6 h cocultures. At 24 h post infection strains with functional cagPAI showed high diversity in the extent of hummingbird phenotype induction ranging from 7% to 34%. cagPAI defective strains induced significantly lower levels of elongation than strains with functional cagPAI with one or more than one EPIYA-C motif (15.1% ± 5.2% vs 18.9% ± 4.7%, P < 0.03; and 15.1% ± 5.2% vs 20.0% ± 5.1%, P < 0.003 respectively). No differences were observed in cellular elongation induction or IL-8 expression among H. pylori strains bearing one and more than one EPIYA-C motifs, neither at 6 h nor at 24 h of coculture. There were no associations between the levels of induction of cell elongation or IL-8 expression and number of EPIYA motifs or pathology. CONCLUSION: The present work describes a lack of association between H. pylori CagA protein EPIYA motifs variations from Colombian isolates and disease-associated cellular responses.

Altered HLA class I and HLA-G expression is associated with IL-10 expression in patients with cervical cancer.

Although high-risk human papillomaviruses (HPVs) are an important risk factor in the etiopathogenesis of cervical cancer, increasing evidence suggests that the ability to avoid immune surveillance seems to be linked to the transforming potential of HPV and a rapid progression to cancer. In other cancer models, IL-10 contributes to impair anti-tumor immune response either by downregulating human leukocyte antigen Class I (HLA-I) expression or by increasing HLA-G expression. To comprehend how these alterations could contribute to evasion of immune surveillance in cervical cancer, we analyzed HLA-I, HLA-G and IL-10 expressions by immunohistochemistry in 63 biopsies from patients with cervical intraepithelial neoplasia III (CIN-III) and cervical cancer. Immunohistochemistry showed absent or weak HLA-I expression in 50/59 cases. In these cases, a high percentage had loss of heterozygosis. IL-10 and HLA-G expression were observed in 46.6 and 27.6% of cases, respectively. Concurrent upregulation of IL-10 was found in 87.5% of HLA-G positive cases (p = 0.000). Similarly, a significant association between IL-10 expression and HLA-I downregulation was found (p = 0.028). Finally, we observed higher HLA-G expression in patients with HLA-I downregulation than in those with normal HLA-I expression (p = 0.004). Our results suggest that, in cervical cancer, the IL-10 expression may induce an immunosuppressive environment by upregulating HLA-G expression and downregulating HLA class I expression.

E6 molecular variants of human papillomavirus (HPV) type 16: an updated and unified criterion for clustering and nomenclature.

Reports on taxonomic identification of E6/HPV 16 variants, don't have a worldwide, updated and unified criterion for clustering and nomenclature. Our aim was to update the existing criterion and propose a new one for clustering and nomenclature for E6/HPV 16 molecular variants based on the descriptive and comparative analyses of nucleotide sequences. A systematic search of the publications between 1991 and 2010 was carried out in PUBMED and manually. 240 E6/HPV 16 variants were identified. 157 were classified as European (E), 24 as Asian (As), 14 as Asian American (AA), 11 as North American 1 (NA 1), 19 as African 1 (Af 1) and 15 as African 2 (Af 2). Three classes were determined for the E, 3 each for the As, Af 2 and AA branches, 4 classes for the NA 1 and 6 for the Af 1 branch. This study reports our results and proposes an updated criterion for clustering and nomenclature that will be useful for E6 variant identification.

[Association of interleukin-1 genetic polymorphism and CagA positive Helicobacter pylori with gastric cancer in Colombia]. / Asociación de los polimorfismos IL-1B-511 e IL-1RN y Helicobacter pylori CagA positivo con cáncer gástrico en una zona de riesgo alto en Colombia.

BACKGROUND: There is an association of interleukin (IL)1B polymorphism with gastric cancer risk. However systematic reviews of the existing evidence have shown that such association varies across populations with different genetic ancestry. AIM: To evaluate the association of IL-1B-511 and IL-1RN polymorphism and Helicobacter pylori IgG antibodies CagA, with gastric cancer in two Colombian cities located in a high risk area for gastric cancer. MATERIAL AND METHODS: A case-control study including 46 gastric cancer cases and 99 controls with non-atrophic gastritis from a high risk zone for gastric cancer. Polymorphism genotyping was carried out by polymerase chain reaction (PCR) and IgG CagA status by ELISA. RESULTS: IgG CagA seropositive individuals had an increased gastric cancer risk (odds ratio (OR) = 11.56; 95% confidence intervals (CI) 2.62-50.91 in Tunja and OR = 19.66, 95%CI 0.98-395 in Bogotá). IL-1B-511TT carriers in Tunja had increased risk of gastric cancer (OR = 11.31; 95%CI 1.20-106.54)), while IL-1RN*2 alelle carriers in Bogotá showed an inverse association with gastric cancer risk (OR = 0.03; 95%CI 0.01-0.65). CONCLUSIONS: This study adds evidence to the positive association of Helicobacter pylori CagA positive strains with non-cardial gastric cancer etiology. There is a possible heterogeneity in the association of IL-1B gene polymorphism with cancer, in populations of similar ethnic background and settled in the same risk area.

Variation in the number of EPIYA-C repeats in CagA protein from Colombian Helicobacter pylori strains and its ability middle to induce hummingbird phenotype in gastric epithelial cells.

INTRODUCTION: Studies using Western Helicobacter pylori strains have shown that a risk factor for gastric cancer is the number of EPIYA-C motifs in the cytotoxin-associated A protein. CagA is delivered into epithelial cells, where it becomes tyrosine phosphorylated in their EPIYA repeats and induces cytoskeleton rearrangements. OBJECTIVES: The objective of this study was to evaluate H. pylori cagA positive strains isolated from Colombian patients with gastroduodenal diseases for the number of EPIYA-C repeats in cagA and their ability to induce cytoskeleton rearrangements in epithelial cells. MATERIALS AND METHODS: We analyzed the 3´ EPIYA repeats region of cagA by PCR in 93 H. pylori cagA positive strains from 49 patients with gastritis, 17 with gastric cancer, and 24 with duodenal ulcer. AGS cells exposed to the various H. pylori isolates were evaluated for rearrangements in their cytoskeleton. RESULTS: Strains with one EPIYA-C were the most frequent in gastritis and duodenal ulcer patients. Strains with three EPIYA-C were mainly found in gastric cancer. We found a significantly higher risk of gastric cancer for individuals infected with strains harboring three EPIYA-C motifs (OR=12.4, CI95%: 2.32-66.3). Strains from gastric cancer showed significantly higher percentages of induction of cytoskeleton rearrangements in comparison with those from gastritis (p Mann-Whitney<0.005). CONCLUSIONS: H. pylori strains with three EPIYA-C repeats can confer an increased risk of cancer to infected individuals.

Helicobacter pylori CagA protein polymorphisms and their lack of association with pathogenesis.

AIM: To investigate Helicobacter pylori (H. pylori) CagA diversity and to evaluate the association between protein polymorphisms and the occurrence of gastric pathologies. METHODS: One hundred and twenty-two clinical isolates of H. pylori cultured from gastric biopsies obtained from Colombian patients with dyspepsia were included as study material. DNA extracted from isolates was used to determine cagA status, amplifying the C-terminal cagA gene region by polymerase chain reaction. One hundred and six strains with a single amplicon were sequenced and results were used to characterize the 3' variable region of the cagA gene. To establish the number and type of tyrosine phosphorylation motifs Glutamine acid-Proline-Isoleucine-Tyrosine-Alanine (EPIYA) bioinformatic analysis using Amino Acid Sequence Analyzer-Amino Acid Sequence Analyzer software was conducted. Analysis of the association between the number of EPIYA motifs and the gastric pathology was performed using chi(2) test and analysis of the presence of EPIYA-C motifs in relation to the pathology was made by logistic regression odds ratios. Comparisons among EPIYA types found and those reported in GenBank were performed using a proportion test in Statistix Analytical Software version 8.0. RESULTS: After amplification of the 3' of the cagA gene, 106 from 122 isolates presented a single amplicon and 16 showed multiple amplicons. As expected, diversity in the size of the cagA unique fragments among isolates was observed. The 106 strains that presented a single amplicon after 3' cagA amplification came from patients with gastritis (19 patients), atrophic gastritis (21), intestinal metaplasia (26), duodenal ulcer (22) and gastric cancer. DNA sequence analysis showed that the differences in size of 3' cagA unique fragments was attributable to the number of EPIYA motifs: 1.9% had two EPIYA motifs, 62.3% had three, 33.0% had four and 2.8% had five motifs. The majority of tested clinical strains (62.3%) were found to harbor the ABC combination of EPIYA motifs and a significant statistical difference was observed between the frequencies of ABCC tyrosine phosphorylation motifs and Western strains sequences deposited in GenBank. CONCLUSION: The present report describes a lack of association between H. pylori CagA-protein polymorphisms and pathogenesis. ABCC high frequency variations compared with Western-strains sequences deposited in GenBank require more investigation.

Variation in the number of EPIYA-C repeats in CagA protein from Colombian Helicobacter pylori strains and its ability to induce hummingbird phenotype in gastric epithelial cells / Variación en el número de repeticiones EPIYA-C en la proteína CagA de aislamientos colombianos de Helicobacter pylori y su capacidad para inducir fenotipo colibrí en células epiteliales gástricas

Introduction. Studies using Western Helicobacter pylori strains have shown that a risk factor for gastric cancer is the number of EPIYA-C motifs in the cytotoxin-associated A protein. CagA is delivered into epithelial cells, where it becomes tyrosine phosphorylated in their EPIYA repeats and induces cytoskeleton rearrangements. Objectives. The objective of this study was to evaluate H. pylori cagA positive strains isolated from Colombian patients with gastroduodenal diseases for the number of EPIYA-C repeats in cagA and their ability to induce cytoskeleton rearrangements in epithelial cells. Materials and methods. We analyzed the 3’ EPIYA repeats region of cagA by PCR in 93 H. pylori cagA positive strains from 49 patients with gastritis, 17 with gastric cancer, and 24 with duodenal ulcer. AGS cells exposed to the various H. pylori isolates were evaluated for rearrangements in their cytoskeleton. Results. Strains with one EPIYA-C were the most frequent in gastritis and duodenal ulcer patients. Strains with three EPIYA-C were mainly found in gastric cancer. We found a significantly higher risk of gastric cancer for individuals infected with strains harboring three EPIYA-C motifs (OR=12.4, CI95%: 2.32-66.3). Strains from gastric cancer showed significantly higher percentages of induction of cytoskeleton rearrangements in comparison with those from gastritis (p Mann-Whitney<0.005). Conclusions. H. pylori strains with three EPIYA-C repeats can confer an increased risk of cancer to infected individuals.

Introducción. En los aislamientos de Helicobacter pylori del hemisferio occidental, se ha observado que el número de repeticiones EPIYA-C en la proteína CagA es un factor de riesgo para cáncer gástrico. La proteína CagA es introducida en la célula epitelial y, posteriormente, es fosforilada en las tirosinas presentes en los motivos EPIYA e induce rearreglos en el citoesqueleto. Objetivos. Nuestro propósito fue evaluar el número de repeticiones EPIYA-C y la habilidad para inducir rearreglos en el citoesqueleto en los aislamientos de H. pylori positivos para cagA, provenientes de pacientes colombianos con enfermedad gastroduodenal. Materiales y métodos. Mediante PCR, se analizó la región 3´ que contiene las repeticiones EPIYA-C, en 93 aislamientos de H. pylori positivos para cagA provenientes de 49 pacientes con gastritis, 17 con cáncer gástrico y 24 con úlcera duodenal. Los rearreglos del citoesqueleto se evaluaron mediante cultivos simultáneos de células AGS con las cepas de H. pylori.Resultados. En gastritis y úlcera duodenal se observó la mayor frecuencia de aislamientos con EPIYA C; los aislamientos con tres repeticiones EPIYA-C se encontraron con mayor frecuencia en cáncer gástrico. Encontramos un riesgo de cáncer gástrico significativamente mayor para individuos infectados con cepas con tres repeticiones EPIYA-C (OR=12,4; IC95% 2,32-66,3). Los aislamientos provenientes de cáncer gástrico mostraron mayores porcentajes de inducción de rearreglos en el citoesqueleto que los observados con aislamientos provenientes de gastritis (prueba de Mann-Whitney menor de 0,005). Conclusiones. La infección con cepas de H. pylori con tres repeticiones EPIYA-C puede conferir un mayor riesgo de desarrollar cáncer gástrico.