Circulating Small Noncoding RNA Profiling as a Potential Biomarker of Atherosclerotic Plaque Composition in Type 1 Diabetes

OBJECTIVE

Cardiovascular disease (CVD) accounts for most deaths in patients with type 1 diabetes (T1D); however, the determinants of plaque composition are unknown. miRNAs regulate gene expression, participate in the development of atherosclerosis, and represent promising CVD biomarkers. This study analyzed the circulating miRNA expression profile in T1D with either carotid calcified (CCP) or fibrous plaque (CFP).

RESEARCH DESIGN AND METHODS

Circulating small noncoding RNAs were sequenced and quantified using next-generation sequencing and bioinformatic analysis in an exploratory set of 26 subjects with T1D with CCP and in 25 with CFP. Then, in a validation set of 40 subjects with CCP, 40 with CFP, and 24 control subjects with T1D, selected miRNA expression was measured by digital droplet PCR. Putative gene targets enriched for pathways implicated in atherosclerosis/vascular calcification/diabetes were analyzed. The patients' main clinical characteristics were also recorded.

RESULTS

miR-503-5p, let-7d-5p, miR-106b-3p, and miR-93-5p were significantly upregulated, while miR-10a-5p was downregulated in patients with CCP compared with CFP (all fold change >±1.5; P < 0.05). All candidate miRNAs showed a significant correlation with LDL-cholesterol, direct for the upregulated and inverse for the downregulated miRNA, in CCP. Many target genes of upregulated miRNAs in CCP participate in osteogenic differentiation, apoptosis, inflammation, cholesterol metabolism, and extracellular matrix organization.

CONCLUSIONS

These findings characterize miRNAs and their signature in the regulatory network of carotid plaque phenotype in T1D, providing new insights into plaque pathophysiology and possibly novel biomarkers of plaque composition.

Genetic determinants of telomere length and risk of pancreatic cancer: A PANDoRA study

Telomere deregulation is a hallmark of cancer. Telomere length measured in lymphocytes (LTL) has been shown to be a risk marker for several cancers. For pancreatic ductal adenocarcinoma (PDAC) consensus is lacking whether risk is associated with long or short telomeres. Mendelian randomization approaches have shown that a score built from SNPs associated with LTL could be used as a robust risk marker. We explored this approach in a large scale study within the PANcreatic Disease ReseArch (PANDoRA) consortium. We analyzed 10 SNPs (ZNF676-rs409627, TERT-rs2736100, CTC1-rs3027234, DHX35-rs6028466, PXK-rs6772228, NAF1-rs7675998, ZNF208-rs8105767, OBFC1-rs9420907, ACYP2-rs11125529 and TERC-rs10936599) alone and combined in a LTL genetic score ("teloscore", which explains 2.2% of the telomere variability) in relation to PDAC risk in 2,374 cases and 4,326 controls. We identified several associations with PDAC risk, among which the strongest were with the TERT-rs2736100 SNP (OR = 1.54; 95%CI 1.35-1.76; p = 1.54 × 10-10 ) and a novel one with the NAF1-rs7675998 SNP (OR = 0.80; 95%CI 0.73-0.88; p = 1.87 × 10-6 , ptrend = 3.27 × 10-7 ). The association of short LTL, measured by the teloscore, with PDAC risk reached genome-wide significance (p = 2.98 × 10-9 for highest vs. lowest quintile; p = 1.82 × 10-10 as a continuous variable). In conclusion, we present a novel genome-wide candidate SNP for PDAC risk (TERT-rs2736100), a completely new signal (NAF1-rs7675998) approaching genome-wide significance and we report a strong association between the teloscore and risk of pancreatic cancer, suggesting that telomeres are a potential risk factor for pancreatic cancer.

Effect of CYP4F2, VKORC1, and CYP2C9 in Influencing Coumarin Dose: A Single-Patient Data Meta-Analysis in More Than 15,000 Individuals

The cytochrome P450 (CYP)4F2 gene is known to influence mean coumarin dose. The aim of the present study was to undertake a meta-analysis at the individual patients level to capture the possible effect of ethnicity, gene-gene interaction, or other drugs on the association and to verify if inclusion of CYP4F2*3 variant into dosing algorithms improves the prediction of mean coumarin dose. We asked the authors of our previous meta-analysis (30 articles) and of 38 new articles retrieved by a systematic review to send us individual patients' data. The final collection consists of 15,754 patients split into a derivation and validation cohort. The CYP4F2*3 polymorphism was consistently associated with an increase in mean coumarin dose (+9% (95% confidence interval (CI) 7-10%), with a higher effect in women, in patients taking acenocoumarol, and in white patients. The inclusion of the CYP4F2*3 in dosing algorithms slightly improved the prediction of stable coumarin dose. New pharmacogenetic equations potentially useful for clinical practice were derived.

Common genetic variants associated with pancreatic adenocarcinoma may also modify risk of pancreatic neuroendocrine neoplasms

Pancreatic neuroendocrine neoplasms (pNEN) account for less than 5% of all pancreatic neoplasms and genetic association studies on susceptibility to the disease are limited. We sought to identify possible overlap of genetic susceptibility loci between pancreatic ductal adenocarcinoma (PDAC) and pNEN; therefore, PDAC susceptibility variants (n = 23) from Caucasian genome-wide association studies (GWAS) were genotyped in 369 pNEN cases and 3277 controls from the PANcreatic Disease ReseArch (PANDoRA) consortium to evaluate the odds associated with pNEN risk, disease onset and tumor characteristics. Main effect analyses showed four PDAC susceptibility variants-rs9854771, rs1561927, rs9543325 and rs10919791 to be associated with pNEN risk. Subsequently, only associations with rs9543325, rs10919791 and rs1561927 were noteworthy with false positive report probability (FPRP) tests. Stratified analyses considering age at onset (50-year threshold), showed rs2736098, rs16986825 and rs9854771 to be associated with risk of developing pNEN at a younger age. Stratified analyses also showed some single nucleotide polymorphisms to be associated with different degrees of tumor grade, metastatic potential and functionality. Our results identify known GWAS PDAC susceptibility loci, which may also be involved in sporadic pNEN etiology and suggest that some genetic mechanisms governing pathogenesis of these two entities may be similar, with few of these loci being more influential in younger cases or tumor subtypes.

CD44v10: An Antimetastatic Membrane Glycoprotein for Pancreatic Cancer

Aims

The aims of this study were 1) to investigate the mRNA pattern of CD44 variants in three primary (MIA PaCa 2, PANC-1, PSN-1) and two metastatic (CAPAN-1, SUIT-2) pancreatic cancer (PC) cell lines; 2) to ascertain whether the genetic transfer of CD44s and CD44v10 modifies the adhesion of PC cells to the extracellular matrix (ECM) in vitro and their metastatic behavior in vivo.

Methods

CD44 mRNA analysis was done by means of RT-PCR. Adhesion to ECM the was assessed using coated microtiter plates. For the study of CD44v10 insertion in the CAPAN-1 line, liposome-mediated DNA transfer was used. SCID mice were employed for in vivo experiments.

Results

CD44v10 mRNA was not expressed by the CAPAN-1 nor by four of the six SUIT-2-derived clones. The stable expression of CD44v10 by modified CAPAN-1 significantly enhanced fibronectin adhesion. Mice without either liver or pancreatic metastases were more frequently found among the animals injected with modified (CD44v10 expressing) than with non-modified CAPAN-1.

Conclusions

1) It is possible to differentiate between metastatic and non-metastatic PC cells on the basis of CD44v10 expression; 2) CD44v10 seems to be involved in mediating fibronectin adhesion in vitro and in counteracting metastases in vivo.

Do pancreatic cancer and chronic pancreatitis share the same genetic risk factors? A PANcreatic Disease ReseArch (PANDoRA) consortium investigation

Pancreatic ductal adenocarcinoma (PDAC) is a very aggressive tumor with a five-year survival of less than 6%. Chronic pancreatitis (CP), an inflammatory process in of the pancreas, is a strong risk factor for PDAC. Several genetic polymorphisms have been discovered as susceptibility loci for both CP and PDAC. Since CP and PDAC share a consistent number of epidemiologic risk factors, the aim of this study was to investigate whether specific CP risk loci also contribute to PDAC susceptibility. We selected five common SNPs (rs11988997, rs379742, rs10273639, rs2995271 and rs12688220) that were identified as susceptibility markers for CP and analyzed them in 2,914 PDAC cases, 356 CP cases and 5,596 controls retrospectively collected in the context of the international PANDoRA consortium. We found a weak association between the minor allele of the PRSS1-PRSS2-rs10273639 and an increased risk of developing PDAC (ORhomozygous  = 1.19, 95% CI 1.02-1.38, p = 0.023). Additionally all the SNPs confirmed statistically significant associations with risk of developing CP, the strongest being PRSS1-PRSS2-rs10273639 (ORheterozygous  = 0.51, 95% CI 0.39-0.67, p = 1.10 × 10-6 ) and MORC4-rs 12837024 (ORhomozygous  = 2.07 (1.55-2.77, ptrend  = 0.7 × 10-11 ). Taken together, the results from our study do not support variants rs11988997, rs379742, rs10273639, rs2995271 and rs12688220 as strong predictors of PDAC risk, but further support the role of these SNPs in CP susceptibility. Our study suggests that CP and PDAC probably do not share genetic susceptibility, at least in terms of high frequency variants.

Lack of Association for Reported Endocrine Pancreatic Cancer Risk Loci in the PANDoRA Consortium

Background: Pancreatic neuroendocrine tumors (PNETs) are rare neoplasms for which very little is known about either environmental or genetic risk factors. Only a handful of association studies have been performed so far, suggesting a small number of risk loci.Methods: To replicate the best findings, we have selected 16 SNPs suggested in previous studies to be relevant in PNET etiogenesis. We genotyped the selected SNPs (rs16944, rs1052536, rs1059293, rs1136410, rs1143634, rs2069762, rs2236302, rs2387632, rs3212961, rs3734299, rs3803258, rs4962081, rs7234941, rs7243091, rs12957119, and rs1800629) in 344 PNET sporadic cases and 2,721 controls in the context of the PANcreatic Disease ReseArch (PANDoRA) consortium.Results: After correction for multiple testing, we did not observe any statistically significant association between the SNPs and PNET risk. We also used three online bioinformatic tools (HaploReg, RegulomeDB, and GTEx) to predict a possible functional role of the SNPs, but we did not observe any clear indication.Conclusions: None of the selected SNPs were convincingly associated with PNET risk in the PANDoRA consortium.Impact: We can exclude a major role of the selected polymorphisms in PNET etiology, and this highlights the need for replication of epidemiologic findings in independent populations, especially in rare diseases such as PNETs. Cancer Epidemiol Biomarkers Prev; 26(8); 1349-51. ©2017 AACR.

SLC22A3 polymorphisms do not modify pancreatic cancer risk, but may influence overall patient survival

Expression of the solute carrier (SLC) transporter SLC22A3 gene is associated with overall survival of pancreatic cancer patients. This study tested whether genetic variability in SLC22A3 associates with pancreatic cancer risk and prognosis. Twenty four single nucleotide polymorphisms (SNPs) tagging the SLC22A3 gene sequence and regulatory elements were selected for analysis. Of these, 22 were successfully evaluated in the discovery phase while six significant or suggestive variants entered the validation phase, comprising a total study number of 1,518 cases and 3,908 controls. In the discovery phase, rs2504938, rs9364554, and rs2457571 SNPs were significantly associated with pancreatic cancer risk. Moreover, rs7758229 associated with the presence of distant metastases, while rs512077 and rs2504956 correlated with overall survival of patients. Although replicated, the association for rs9364554 did not pass multiple testing corrections in the validation phase. Contrary to the discovery stage, rs2504938 associated with survival in the validation cohort, which was more pronounced in stage IV patients. In conclusion, common variation in the SLC22A3 gene is unlikely to significantly contribute to pancreatic cancer risk. The rs2504938 SNP in SLC22A3 significantly associates with an unfavorable prognosis of pancreatic cancer patients. Further investigation of this SNP effect on the molecular and clinical phenotype is warranted.

Functional single nucleotide polymorphisms within the cyclin-dependent kinase inhibitor 2A/2B region affect pancreatic cancer risk

The CDKN2A (p16) gene plays a key role in pancreatic cancer etiology. It is one of the most commonly somatically mutated genes in pancreatic cancer, rare germline mutations have been found to be associated with increased risk of developing familiar pancreatic cancer and CDKN2A promoter hyper-methylation has been suggested to play a critical role both in pancreatic cancer onset and prognosis. In addition several unrelated SNPs in the 9p21.3 region, that includes the CDNK2A, CDNK2B and the CDNK2B-AS1 genes, are associated with the development of cancer in various organs. However, association between the common genetic variability in this region and pancreatic cancer risk is not clearly understood. We sought to fill this gap in a case-control study genotyping 13 single nucleotide polymorphisms (SNPs) in 2,857 pancreatic ductal adenocarcinoma (PDAC) patients and 6,111 controls in the context of the Pancreatic Disease Research (PANDoRA) consortium. We found that the A allele of the rs3217992 SNP was associated with an increased pancreatic cancer risk (ORhet=1.14, 95% CI 1.01-1.27, p=0.026, ORhom=1.30, 95% CI 1.12-1.51, p=0.00049). This pleiotropic variant is reported to be a mir-SNP that, by changing the binding site of one or more miRNAs, could influence the normal cell cycle progression and in turn increase PDAC risk. In conclusion, we observed a novel association in a pleiotropic region that has been found to be of key relevance in the susceptibility to various types of cancer and diabetes suggesting that the CDKN2A/B locus could represent a genetic link between diabetes and pancreatic cancer risk.

Let-7c down-regulation in Helicobacter pylori-related gastric carcinogenesis

Aberrant let-7c microRNA (miRNA) expression has been observed in Helicobacter pylori-related gastric cancer (GC) but fragmentary information is available on the let-7c dysregulation occurring with each phenotypic change involved in gastric carcinogenesis. Let-7c expression was assessed (qRT-PCR) in a series of 175 gastric biopsy samples representative of the whole spectrum of phenotypic changes involved in H. pylori-related gastric oncogenesis including: i) normal gastric mucosa, as obtained from dyspeptic controls (40 biopsy samples); ii) non-atrophic gastritis (40 samples); iii) atrophic-metaplastic gastritis (35 samples); iv) intra-epithelial neoplasia (30 samples); v) GC (30 samples). Let-7c expression was also tested in 20 biopsy samples obtained from 10 patients before and after H. pylori eradication therapy (median follow-up: 10 weeks; range: 7-14). The results obtained were further validated by in situ hybridization on multiple tissue specimens obtained from 5 surgically treated H. pylori-related GCs. The study also included 40 oxyntic biopsy samples obtained from serologically/histologically confirmed autoimmune gastritis (AIG: 20 corpus-restricted, non-atrophic; 20 corpus-restricted, atrophic-metaplastic). Let-7c expression dropped from non-atrophic gastritis to atrophic-metaplastic gastritis, intra-epithelial neoplasia, and invasive GC (p<0.001). It rose again significantly following H. pylori eradication (p=0.009). As in the H. pylori model, AIG also featured a significant let-7c down-regulation (p<0.001). The earliest phases of the two pathways to gastric oncogenesis (H. pylori-environmental and autoimmune host-related) are characterized by similar let-7c dysregulations. In H. pylori infection, let-7c down-regulation regresses after the bacterium's eradication, while it progresses significantly with the increasing severity of the histological lesions.

Pancreatic cancer cells invasiveness is mainly affected by interleukin-1beta not by transforming growth factor-beta1

BACKGROUND

We investigated in vitro whether IL-1beta and TGF-beta1 affect pancreatic cancer cell growth, adhesion to the extracellular matrix and Matrigel invasion.

MATERIALS AND METHODS

Adhesion to fibronectin, laminin and type I collagen, and Matrigel invasion after stimulation with saline, IL-1beta and TGF-beta1 were evaluated using three primary and three metastatic pancreatic cancer cell lines.

RESULTS

Extracellular matrix adhesion of control cells varied independently of the metastatic characteristics of the studied cell lines, whereas Matrigel invasion of control cells was partly correlated with the in vivo metastatic potential. IL-1beta did not influence extracellular matrix adhesion, whereas it significantly enhanced the invasiveness of three of the six cell lines. TGF-beta1 affected the adhesion of one cell line, and exerted contrasting effects on Matrigel invasion of different cell lines.

CONCLUSIONS

IL-1beta enhances the invasive capacity of pancreatic cancer cells, whereas TGF-beta1 has paradoxical effects on pancreatic cancer cells; this makes it difficult to interfere with TGF-beta1 signaling in pancreatic cancer treatment.

Different effects of H. pylori water extracts on cytokines, pepsinogen C and gastrin mucosal release in patients with or without duodenal ulcer

In the present study we ascertained whether cagA positive and negative H. pylori strains release water soluble products that can influence the production of gastric mucosal cytokines and endocrine (gastrin) or exocrine (pepsinogen C) secretion in 23 H. pylori positive and 19 H. pylori negative patients. Antral biopsies were obtained to classify inflammation, activity, atrophy, intestinal metaplasia and H. pylori density grade. The cagA gene was identified by means of the polymerase chain reaction (PCR) in H. pylori positive colonies after culture of mucosal samples. Three antral biopsies from each patient were incubated with (1.) Water extracts from cagA positive, (2.) Water extracts from cagA negative strains or (3.) H2O (control) at 37 degrees C in a CO2 incubator for 24 hrs. Gastrin, pepsinogen C, IL-1 beta, IL-8, GMCSF, and TNF alpha were measured in the supernatants and mucosal homogenates. H. pylori infection was significantly associated with an increased antral inflammation and activity (chi 2 = 21.7, p < 0.001 and chi 2 = 42.0, p < 0.001), and increased mucosal levels of IL-1 beta, IL-8 and TNF alpha. Water extracts from cagA positive strains enhanced the release of PGC in mucosal biopsy supernatants (p < 0.05) when patients were considered overall and the release of TNF alpha (p < 0.05) when only patients with duodenal ulcer were considered. Water extracts from cagA negative strains stimulated gastrin secretion (p < 0.05). None of the remaining cytokines were influenced by H. pylori water extracts. In conclusion, pepsinogen C and TNF alpha can be induced by cagA positive water extracts and may contribute to damage the gastric and duodenal mucosa. Our findings indicate that in patients with H. pylori infection the increase of the mucosal levels of IL-1 beta and IL-8 does not depend on H. pylori water soluble products, but probably depends on the entire bacterium.

Antigastric autoantibodies in Helicobacter pylori infection: role in gastric mucosal inflammation

The aim of the study was to ascertain whether there is an association between the presence of serum parietal cell autoantibodies (PCA) and: (1) Helicobacter pylori infection; (2) the presence and degree of gastritis and intestinal metaplasia; and (3) the H. pylori infecting strain. Gastric mucosal biopsies were obtained from 49 consecutive patients in order to assess and grade gastritis, make a histological diagnosis, and culture and genotype H. pylori. H. pylori infection was present in 26 patients (group 1), had been present in 17 patients (group 2), and the remaining 6 (group 3) had never had the infection. The infecting strain was cagA positive in 21 of 26 group 1 patients. Positive PCA results were found in 84%, 76%, and 14% of patients in groups 1, 2, and 3, respectively. PCA results were correlated with anti-H. pylori antibody titers (P<0.05). In group 2 patients, PCA were associated with the degree of antral gastritis (Fisher's exact test P<0.05). cagA status was not associated with the presence of PCA (chi2=0.68, NS). The frequency of positive findings for PCA in group 2 was higher in patients with (90%) than in those without (50%) intestinal metaplasia.

IN CONCLUSION

(1) H. pylori infection is associated with the production of PCA, which, after eradication of the infection, persist and might contribute to the persistent antral chronic gastritis and intestinal metaplasia; (2) the gastric lesions associated with infections sustained by the more-virulent H. pylori strains do not appear to be due to the induction of antigastric autoantibodies.

[Diagnosis of Helicobacter pylori infection: comparison of techniques]

Several diagnostic assays are available for evaluating Helicobacter pylori infection: histological examination, culture of gastric biopsies, urea breath test and serology. Recently a new enzyme immunoassay has been introduced for the detection of H. pylori antigens in stool samples (HpSA). The aim of our study was to evaluate and compare diagnostic efficacy of HpSA with histological examination, culture, urea breath test and serology in a group of 95 patients. Patients were classified H. pylori positive (43) or negative (52) on the basis of histology, culture and urea breath test. HpSA optical densities were significantly higher in infected patients compared to those obtained in H. pylori-negative patients (t = 5.47, p < 0.001). Overall, with a fixed cut-off of 0.1 unit of optical density, the sensitivity was 79% and the specificity 100%. In the H. pylori positive patients, HpSA optical density correlated with bacterial load histologically evaluated in the gastric antrum (r = 0.405, p < 0.05) and was inverse correlated with levels of serum IgG elicited against H. pylori (r = -0.315, p < 0.05). Considering patients with a positive HpSA finding and/or levels of anti-H. pylori antibodies upper than 30 U/mL, sensitivity in detecting infected patients was 98%.

IN CONCLUSION

(1) immunodetection of H. pylori antigens in stools is a good alternative of breath test; (2) a reduction in H. pylori density grade might be accompanied by low HpSA optical density, leading to a false negative result and (3) combining the HpSA determination with the serum detection of anti-H. pylori antibodies a better clinical sensitivity is obtained.

CEA mRNA identification in peripheral blood is feasible for colorectal, but not for gastric or pancreatic cancer staging

OBJECTIVE

It has been suggested that the molecular identification of cancer cells in the circulation may be useful in predicting the presence of micrometastasis in several cancer types. The aim of the present study was therefore to assess the feasibility of CEA mRNA identification in blood for diagnosing and staging colorectal, gastric and pancreatic cancer.

METHODS

We studied 16 control subjects, 69 patients with colorectal (CRC), 30 with gastric (GC), 27 with pancreatic cancer (PC) and 8 with benign diseases of the pancreatobiliary tree. At diagnosis CEA mRNA was identified in peripheral blood by means of a RT-PCR procedure.

RESULTS

The specificity of this test in control subjects was 94%, and its sensitivity in identifying CRC, GC and PC were 34, 37 and 41%, respectively. False-positive findings were recorded in 25% patients with benign diseases. No association was found between CEA mRNA and stage in patients with GC or PC. In CRC patients, positive CEA mRNA findings were correlated with local spread (chi(2) = 14.6, p<0.01), lymph node (chi(2) = 18.95, p<0.001) and distant metastasis (chi(2) = 11.3, p<0.001). In these cases, CEA mRNA, but not CEA, was entered in stepwise discriminant analysis to classify the presence of lymph node metastasis.

CONCLUSIONS

The molecular detection of micrometastasis in the blood by means of CEA mRNA identification is feasible for colorectal, but not for gastric or pancreatic cancer staging. Further studies are needed in order to define the clinical utility of this marker also in follow-up protocols.

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

BACKGROUND

The aims of our study were twofold. First, we sought to evaluate in symptomatic children the influence of the Helicobacter pylori genotype on gastritis, abdominal pain, and circulating anti-H. pylori IgG antibodies (anti-H. pylori IgG) or pepsinogen A (PGA) and C (PGC). Additionally, we sought to assess anti-H. pylori IgG, PGA, and PGC patterns in a large cohort (N = 921) of asymptomatic children.

MATERIALS AND METHODS

In 183 symptomatic children, H. pylori infection and the presence of gastritis were evaluated by histology. In a subgroup of 20 H. pylori-positive children, the H. pylori genotype was evaluated also by polymerase chain reaction. Nine hundred and twenty-one asymptomatic children, aged 11 to 14 years, were studied by anti-H. pylori IgG, PGA, and PGC serum determination.

RESULTS

The infection was found in 33 of 183 symptomatic children; among the 20 H. pylori-positive children for which the H. pylori genotype was available, cagA was present or absent in equal percentages. H. pylori infection was associated with more severe gastritis and higher serum levels of anti-H. pylori IgG and PGC but not with abdominal pain. In infected children, higher levels of anti-H. pylori IgG and the presence of abdominal pain were associated with infections caused by cagA-positive strains. In the cohort of 921 asymptomatic children, raised levels of anti-H. pylori IgG, PGA, and PGC were found in approximately 5% of the cases.

CONCLUSIONS

Infection with cagA-positive H. pylori strains can be associated with increased frequency of reported abdominal pain and higher circulating levels of anti-H. pylori IgG. The serological assessment of H. pylori IgG using H. pylori antigens containing significant amounts of cagA protein may, therefore, underestimate the true prevalence of infection.

Serum antibodies anti-H. pylori and anti-CagA: a comparison between four different assays

The authors compare efficacy of two ELISA assays (one supplied by DIAMEDIX [Delta Biological s.r.l.], and the other by RADIM [RADIM I]) in detecting total anti-H. pylori antibodies, and of two further ELISA methods (one supplied by EUROSPITAL [Helori CTX IgG] and the other by RADIM [RADIM 2]) in identifying anti-CagA antibodies, using sera from 69 controls (20 adults and 49 children) and from 96 patients, obtained before endoscopy. Seventy-three of the patients had H. pylori infection, while the remaining 23 were H. pylori negative (histology and polymerase chain reaction [PCR]). Fifty-two of the H. pylori positive patients, had cagA-positive strain infection, identified by PCR. The DIAMEDIX assay was found to be more sensitive (92%) than RADIM 1 (79%) in identifying H. pylori positive patients, irrespective of the infecting strain. On the other hand, the DIAMEDIX assay was less specific than RADIM 1 for H. pylori-negative patients (43% vs. 83%). However, when patients already treated for H. pylori infection were excluded from the group of H. pylori-negative patients, the DIAMEDIX assay had a specificity of 89%. In identifying anti-CagA antibodies, the kit supplied by RADIM (RADIM 2) had a sensitivity of 90% and a specificity of 94%, whereas that supplied by EUROSPITAL had a sensitivity of 100% and a specificity of 76%. The performances of the two methods in the identification of anti-CagA antibodies were found to be similar. The authors conclude that, in view of its high sensitivity, the DIAMEDIX assay may be useful in screening for H. pylori infection.