Salivary proteomic analysis in asymptomatic and symptomatic SARS-CoV-2 infection: Innate immunity, taste perception and FABP5 proteins make the difference

BACKGROUND AND AIM

SARS-CoV-2 infection spawns from an asymptomatic condition to a fatal disease. Age, comorbidities, and several blood biomarkers are associated with infection outcome. We searched for biomarkers by untargeted and targeted proteomic analysis of saliva, a source of viral particles and host proteins.

METHODS

Saliva samples from 19 asymptomatic and 16 symptomatic SARS-CoV-2 infected subjects, and 20 controls were analyzed by LC-MS/MS for untargeted peptidomic (flow through of 10 kDa filter) and proteomic (trypsin digestion of filter retained proteins) profiling.

RESULTS

Peptides from 53 salivary proteins were identified. ADF was detected only in controls, while IL1RA only in infected subjects. PRPs, DSC2, FABP5, his-1, IL1RA, PRH1, STATH, SMR3B, ANXA1, MUC7, ACTN4, IGKV1-33 and TGM3 were significantly different between asymptomatic and symptomatic subjects. Retained proteins were 117, being 11 highly different between asymptomatic and symptomatic (fold change ≥2 or ≤-2). After validation by LC-MS/MS-SRM (selected reaction monitoring analysis), the most significant discriminant proteins at PCA were IL1RA, CYSTB, S100A8, S100A9, CA6, and FABP5.

CONCLUSIONS

The differentially abundant proteins involved in innate immunity (S100 proteins), taste (CA6 and cystatins), and viral binding to the host (FABP5), appear to be of interest for use as potential biomarkers and drugs targets.

Salivary SARS-CoV-2 antigen rapid detection: A prospective cohort study

Background and aim

SARS-CoV-2 quick testing is relevant for the containment of new pandemic waves. Antigen testing in self-collected saliva might be useful. We compared salivary and naso-pharyngeal swab (NPS) SARS-CoV-2 antigen detection by a rapid chemiluminescent assay (CLEIA) and two different point-of-care (POC) immunochromatographic assays, with results of molecular testing.

Methods

234 patients were prospectively enrolled. Paired self-collected saliva (Salivette) and NPS were obtained to perform rRT-PCR, chemiluminescent (Lumipulse G) and POC (NPS: Fujirebio and Abbott; saliva: Fujirebio) for SARS-CoV-2 antigen detection.

Results

The overall agreement between NPS and saliva rRT-PCR was 78.7%, reaching 91.7% at the first week from symptoms. SARS-CoV-2 CLEIA antigen was highly accurate in distinguishing positive and negative NPS (ROC-AUC = 0.939, 95%CI:0.903–0.977), with 81.6% sensitivity and 93.8% specificity. This assay on saliva reached the optimal value within 7 days from symptoms onset (Sensitivity: 72%; Specificity: 97%). Saliva POC antigen was limited in sensitivity (13%), performing better in NPS (Sensitivity: 48% and 66%; Specificity: 100% and 99% for Espline and Abbott respectively), depending on viral loads.

Conclusions

Self-collected saliva is a valid alternative to NPS for SARS-CoV-2 detection by molecular, but also by CLEIA antigen testing, which is therefore potentially useful for large scale screening.

SARS-CoV-2 RNA identification in nasopharyngeal swabs: issues in pre-analytics

Objectives

The direct identification of SARS-CoV-2 RNA in nasopharyngeal swabs is recommended for diagnosing the novel COVID-19 disease. Pre-analytical determinants, such as sampling procedures, time and temperature storage conditions, might impact on the end result. Our aim was to evaluate the effects of sampling procedures, time and temperature of the primary nasopharyngeal swabs storage on real-time reverse-transcription polymerase chain reaction (rRT-PCR) results.

Methods

Each nasopharyngeal swab obtained from 10 hospitalized patients for COVID-19 was subdivided in 15 aliquots: five were kept at room temperature; five were refrigerated (+4 °C); five were immediately mixed with the extraction buffer and refrigerated at +4 °C. Every day and for 5 days, one aliquot per condition was analyzed (rRT-PCR) for SARS-CoV-2 gene E and RNaseP and threshold cycles (Ct) compared. To evaluate manual sampling, 70 nasopharyngeal swabs were sampled twice by two different operators and analyzed separately one from the other.

Results

A total of 6/10 swabs were SARS-CoV-2 positive. No significant time or storage-dependent variations were observed in SARS-CoV-2 Ct. Re-sampling of swabs with SARS-CoV-2 Ct lower than 33 resulted in highly reproducible results (CV=2.9%), while a high variability was observed when Ct values were higher than 33 (CV=10.3%).

Conclusions

This study demonstrates that time and temperature of nasopharyngeal swabs storage do not significantly impact on results reproducibility. However, swabs sampling is a critical step, and especially in case of low viral load, might be a potential source of diagnostic errors.

MALDI-TOF peptidomic analysis of serum and post-prostatic massage urine specimens to identify prostate cancer biomarkers

Background

Lower urinary tract symptoms (LUTS) and prostate specific antigen-based parameters seem to have only a limited utility for the differential diagnosis of prostate cancer (PCa). MALDI-TOF/MS peptidomic profiling could be a useful diagnostic tool for biomarker discovery, although reproducibility issues have limited its applicability until now. The current study aimed to evaluate a new MALDI-TOF/MS candidate biomarker.

Methods

Within- and between-subject variability of MALDI-TOF/MS-based peptidomic urine and serum analyses were evaluated in 20 and 15 healthy donors, respectively. Normalizations and approaches for accounting below limit of detection (LOD) values were utilized to enhance reproducibility, while Monte Carlo experiments were performed to verify whether measurement error can be dealt with LOD data. Post-prostatic massage urine and serum samples from 148 LUTS patients were analysed using MALDI-TOF/MS. Regression-calibration and simulation and extrapolation methods were used to derive the unbiased association between peptidomic features and PCa.

Results

Although the median normalized peptidomic variability was 24.9%, the within- and between-subject variability showed that median normalization, LOD adjustment, and log₂ data transformation were the best combination in terms of reliability; in measurement error conditions, intraclass correlation coefficient was a reliable estimate when the LOD/2 was substituted for below LOD values. In the patients studied, 43 peptides were shared by the urine and serum, and several features were found to be associated with PCa. Only few serum features, however, show statistical significance after the multiple testing procedures were completed. Two serum fragmentation patterns corresponded to the complement C4-A.

Conclusions

MALDI-TOF/MS serum peptidome profiling was more efficacious with respect to post-prostatic massage urine analysis in discriminating PCa.

Electronic supplementary material

The online version of this article (10.1186/s12014-018-9199-8) contains supplementary material, which is available to authorized users.

Improving IBD diagnosis and monitoring by understanding preanalytical, analytical and biological fecal calprotectin variability

Background:

The appropriate clinical use of fecal calprotectin (fCal) might be compromised by incomplete harmonization between assays and within- and between-subjects variability. Our aim was to investigate the analytical and biological variability of fCal in order to provide tools for interpreting fCal in the clinical setting.

Methods:

Experiments were conducted to investigate the effects of temperature and storage time on fCal. Thirty-nine controls were enrolled to verify biological variability, and a case-control study was conducted on 134 controls and 110 IBD patients to compare the clinical effectiveness of three different fCal assays: ELISA, CLIA and turbidimetry.

Results:

A 12% decline in fCal levels was observed within 24 h following stool collection irrespective of storage temperature. Samples were unstable following a longer storage time interval at room temperature. Within- and between-subjects fCal biological variability, at 31% and 72% respectively, resulted in a reference change value (RCV) in the region of 100%. fCal sensitivity in distinguishing between controls and IBD patients is satisfactory (68%), and the specificity high (93%) among young (<65 years), but not among older (≥65 years) subjects (ROC area: 0.584; 95% CI: 0.399–0.769). Among the young, assays have different optimal thresholds (120 μg/g for ELISA, 50 μg/g for CLIA and 100 μg/g for turbidimetry).

Conclusions:

We recommend a standardized preanalytical protocol for fCal, avoiding storage at room temperature for more than 24 h. Different cutoffs are recommended for different fCal assays. In monitoring, the difference between two consecutive measurements appears clinically significant when higher than 100%, the fCal biological variability-derived RCV.

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.

PDAC-derived exosomes enrich the microenvironment in MDSCs in a SMAD4-dependent manner through a new calcium related axis

Tumor genetics and escape from immune surveillance concur in the poor prognosis of PDAC. In this study an experimental model was set up to verify whether SMAD4, deleted in about 55% PDAC and associated with poor prognosis, is involved in determining immunosuppression through Exosomes (Exo). Potential mechanisms and mediators underlying SMAD4-dependent immunosuppression were evaluated by studying intracellular calcium (Fluo-4), Exo-miRNAs (microarray) and Exo-proteins (SILAC). Two PDAC cell lines expressing (BxPC3-SMAD4+) or not-expressing (BxPC3) SMAD4 were used to prepare Exo-enriched conditioned media, employed in experiments with blood donors PBMCs. Exo expanded myeloid derived suppressor cells (gMDSC and mMDSC, flow cytometry) and altered intracellular calcium fluxes in an SMAD4 dependent manner. BxPC3-SMAD4+, but mainly BxPC3 Exo, increased calcium fluxes of PBMCs (p = 0.007) and this increased intracellular calcium trafficking characterized mMDSCs. The analysis of de-regulated Exo-miRNAs and transfection experiments revealed hsa-miR-494-3p and has-miR-1260a as potential mediators of SMAD4-associated de-regulated calcium fluxes. Eleven main biological processes were identified by the analysis of SMAD4-associated de-regulated Exo-proteins, including translation, cell adhesion, cell signaling and glycolysis. A reverse Warburg effect was observed by treating PBMCs with PDAC-derived Exo: BxPC3 Exo induced a higher glucose consumption and lactate production than BxPC3-SMAD4+ Exo. Conclusion: PDAC-derived Exo from cells with, but mainly from those without SMAD4 expression, create an immunosuppressive myeloid cell background by increasing calcium fluxes and glycolysis through the transfer of SMAD4-related differentially expressed miRNAs and proteins.

Relevance of pre-analytical blood management on the emerging cardiovascular protein biomarkers TWEAK and HMGB1 and on miRNA serum and plasma profiling

BACKGROUND

Disease-independent sources of biomarker variability include pre-analytical, analytical and biological variance. The aim of the present study was to evaluate whether the pre-analytical phase has any impact on the emerging heart disease TWEAK and HMGB1 protein markers and miRNA biomarkers, and whether peptidome profiling allows the identification of pre-analytical quality markers.

METHODS

An assessment was made of sample type (serum, EDTA-Plasma, Citrate-Plasma, ACD-plasma, Heparin-plasma), temperature of sample storage (room temperature or refrigerated), time of sample storage (0.5, 3, 6 and 9h) and centrifugation (one or two-step). Aliquots of all processed samples were immediately frozen (-80°C) before analysis. Proteins were assayed by ELISAs, miRNA expression profile by microarray and peptidome profiling by MALDI-TOF/MS.

RESULTS

Temperature, time and centrifugation had no impact on TWEAK and HMGB1 results, which were significantly influenced by matrix type, TWEAK levels being significantly higher (F=194.7, p<0.0001), and HMGB1 levels significantly lower (F=36.32, p<0.0001) in serum than in any other plasma type. Unsuitable miRNA results were obtained using Heparin-plasma. Serum miRNA expression profiles depended mainly on temperature, while EDTA-plasma miRNA expression profiles were strongly affected by the centrifugation method used. MALDI-TOF/MS allowed the identification of seven features as indices of pre-analytical serum (m/z at 1206, 1350, 1865 and 2021) or EDTA-plasma (m/z 1897, 2740 and 2917) degradation.

CONCLUSIONS

Serum and EDTA-plasma allow the analysis of both proteins and miRNA emerging biomarkers of heart diseases. Refrigerated storage prevents an altered miRNA expression profile also in cases of a prolonged time-interval between blood drawing and processing.

SMAD4 loss enables EGF, TGFβ1 and S100A8/A9 induced activation of critical pathways to invasion in human pancreatic adenocarcinoma cells

Epidermal Growth Factor (EGF) receptor overexpression, KRAS, TP53, CDKN2A and SMAD4 mutations characterize pancreatic ductal adenocarcinoma. This mutational landscape might influence cancer cells response to EGF, Transforming Growth Factor β1 (TGFβ1) and stromal inflammatory calcium binding proteins S100A8/A9. We investigated whether chronic exposure to EGF modifies in a SMAD4-dependent manner pancreatic cancer cell signalling, proliferation and invasion in response to EGF, TGFβ1 and S100A8/A9. BxPC3, homozigously deleted (HD) for SMAD4, and BxPC3-SMAD4+ cells were or not stimulated with EGF (100 ng/mL) for three days. EGF pre-treated and non pretreated cells were stimulated with a single dose of EGF (100 ng/mL), TGFβ1 (0,02 ng/mL), S100A8/A9 (10 nM). Signalling pathways (Reverse Phase Protein Array and western blot), cell migration (Matrigel) and cell proliferation (XTT) were evaluated. SMAD4 HD constitutively activated ERK and Wnt/β-catenin, while inhibiting PI3K/AKT pathways. These effects were antagonized by chronic EGF, which increased p-BAD (anti-apoptotic) in response to combined TGFβ1 and S100A8/A9 stimulation. SMAD4 HD underlied the inhibition of NF-κB and PI3K/AKT in response to TGFβ1 and S100A8/A9, which also induced cell migration. Chronic EGF exposure enhanced cell migration of both BxPC3 and BxPC3-SMAD4+, rendering the cells less sensitive to the other inflammatory stimuli. In conclusion, SMAD4 HD is associated with the constitutive activation of the ERK and Wnt/β-catenin signalling pathways, and favors the EGF-induced activation of multiple signalling pathways critical to cancer proliferation and invasion. TGFβ1 and S100A8/A9 mainly inhibit NF-κB and PI3K/AKT pathways and, when combined, sinergize with EGF in enhancing anti-apoptotic p-BAD in a SMAD4-dependent manner.

A Randomized Trial of Pharmacogenetic Warfarin Dosing in Naïve Patients with Non-Valvular Atrial Fibrillation

Genotype-guided warfarin dosing have been proposed to improve patient’s management. This study is aimed to determine whether a CYP2C9- VKORC1- CYP4F2-based pharmacogenetic algorithm is superior to a standard, clinically adopted, pharmacodynamic method. Two-hundred naïve patients with non-valvular atrial fibrillation were randomized to trial arms and 180 completed the study. No significant differences were found in the number of out-of-range INRs (INR<2.0 or >3.0) (p = 0.79) and in the mean percentage of time spent in the therapeutic range (TTR) after 19 days in the pharmacogenetic (51.9%) and in the control arm (53.2%, p = 0.71). The percentage of time spent at INR>4.0 was significantly lower in the pharmacogenetic (0.7%) than in the control arm (1.8%) (p = 0.02). Genotype-guided warfarin dosing is not superior in overall anticoagulation control when compared to accurate clinical standard of care.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01178034.

TERT gene harbors multiple variants associated with pancreatic cancer susceptibility

A small number of common susceptibility loci have been identified for pancreatic cancer, one of which is marked by rs401681 in the TERT-CLPTM1L gene region on chromosome 5p15.33. Because this region is characterized by low linkage disequilibrium, we sought to identify whether additional single nucleotide polymorphisms (SNPs) could be related to pancreatic cancer risk, independently of rs401681. We performed an in-depth analysis of genetic variability of the telomerase reverse transcriptase (TERT) and the telomerase RNA component (TERC) genes, in 5,550 subjects with pancreatic cancer and 7,585 controls from the PANcreatic Disease ReseArch (PANDoRA) and the PanScan consortia. We identified a significant association between a variant in TERT and pancreatic cancer risk (rs2853677, odds ratio = 0.85; 95% confidence interval = 0.80-0.90, p = 8.3 × 10(-8)). Additional analysis adjusting rs2853677 for rs401681 indicated that the two SNPs are independently associated with pancreatic cancer risk, as suggested by the low linkage disequilibrium between them (r(2) = 0.07, D' = 0.28). Three additional SNPs in TERT reached statistical significance after correction for multiple testing: rs2736100 (p = 3.0 × 10(-5) ), rs4583925 (p = 4.0 × 10(-5) ) and rs2735948 (p = 5.0 × 10(-5) ). In conclusion, we confirmed that the TERT locus is associated with pancreatic cancer risk, possibly through several independent variants.

TNFA Haplotype Genetic Testing Improves HLA in Estimating the Risk of Celiac Disease in Children

Background

TNF-α and IFN-γ play a role in the development of mucosal damage in celiac disease (CD). Polymorphisms of TNFA and IFNG genes, as well as of the TNFRSF1A gene, encoding the TNF-α receptor 1, might underlie different inter-individual disease susceptibility over a common HLA risk background. The aims of this study were to ascertain whether five SNPs in the TNFA promoter (-1031T>C,-857C>T,-376G>A,-308G>A,-238G>A), sequence variants of the TNFRSF1A gene and IFNG +874A>T polymorphism are associated with CD in a HLA independent manner.

Methods

511 children (244 CD, 267 controls) were genotyped for HLA, TNFA and INFG (Real Time PCR). TNFRSF1A variants were studied (DHPLC and sequence).

Results

Only the rare TNFA-1031C (OR=0.65, 95% CI:0.44-0.95), -857T (OR=0.42, 95% CI:0.27-0.65), -376A (OR=2.25, 95% CI:1.12-4.51) and -308A (OR=4.76, 95% CI:3.12-7.26) alleles were significantly associated with CD. One TNFRSF1A variant was identified (c.625+10A>G, rs1800693), but not associated with CD. The CD-correlated TNFA SNPs resulted in six haplotypes. Two haplotypes were control-associated (CCGG and TTGG) and three were CD-associated (CCAG, TCGA and CCGA). The seventeen inferred haplotype combinations were grouped (A to E) based on their frequencies among CD. Binary logistic regression analysis documented a strong association between CD and HLA (OR for intermediate risk haplotypes=178; 95% CI:24-1317; OR for high risk haplotypes=2752; 95% CI:287-26387), but also an HLA-independent correlation between CD and TNFA haplotype combination groups. The CD risk for patients carrying an intermediate risk HLA haplotype could be sub-stratified by TNFA haplotype combinations.

Conclusion

TNFA promoter haplotypes associate with CD independently from HLA. We suggest that their evaluation might enhance the accuracy in estimating the CD genetic risk.

Inflammation and pancreatic cancer: molecular and functional interactions between S100A8, S100A9, NT-S100A8 and TGFβ1

BACKGROUND

In order to gain further insight on the crosstalk between pancreatic cancer (PDAC) and stromal cells, we investigated interactions occurring between TGFβ1 and the inflammatory proteins S100A8, S100A9 and NT-S100A8, a PDAC-associated S100A8 derived peptide, in cell signaling, intracellular calcium (Cai2+) and epithelial to mesenchymal transition (EMT). NF-κB, Akt and mTOR pathways, Cai2+ and EMT were studied in well (Capan1 and BxPC3) and poorly differentiated (Panc1 and MiaPaCa2) cell lines.

RESULTS

NT-S100A8, one of the low molecular weight N-terminal peptides from S100A8 to be released by PDAC-derived proteases, shared many effects on NF-κB, Akt and mTOR signaling with S100A8, but mainly with TGFβ1. The chief effects of S100A8, S100A9 and NT-S100A8 were to inhibit NF-κB and stimulate mTOR; the molecules inhibited Akt in Smad4-expressing, while stimulated Akt in Smad4 negative cells. By restoring Smad4 expression in BxPC3 and silencing it in MiaPaCa2, S100A8 and NT-S100A8 were shown to inhibit NF-κB and Akt in the presence of an intact TGFβ1 canonical signaling pathway. TGFβ1 counteracted S100A8, S100A9 and NT-S100A8 effects in Smad4 expressing, not in Smad4 negative cells, while it synergized with NT-S100A8 in altering Cai2+ and stimulating PDAC cell growth. The effects of TGFβ1 on both EMT (increased Twist and decreased N-Cadherin expression) and Cai2+ were antagonized by S100A9, which formed heterodimers with TGFβ1 (MALDI-TOF/MS and co-immuno-precipitation).

CONCLUSIONS

The effects of S100A8 and S100A9 on PDAC cell signaling appear to be cell-type and context dependent. NT-S100A8 mimics the effects of TGFβ1 on cell signaling, and the formation of complexes between TGFβ1 with S100A9 appears to be the molecular mechanism underlying the reciprocal antagonism of these molecules on cell signaling, Cai2+ and EMT.

Pancreatic tumors and immature immunosuppressive myeloid cells in blood and spleen: role of inhibitory co-stimulatory molecules PDL1 and CTLA4. An in vivo and in vitro study

BACKGROUND

Blood and spleen expansion of immature myeloid cells (IMCs) might compromise the immune response to cancer. We studied in vivo circulating and splenic T lymphocyte and IMC subsets in patients with benign and malignant pancreatic diseases. We ascertained in vitro whether pancreatic adenocarcinoma (PDAC)-associated IMC subsets are induced by tumor-derived soluble factors and whether they are immunosuppressive focusing on the inhibitory co-stimulatory molecules PDL1 and CTLA4.

METHODOLOGY AND PRINCIPAL FINDINGS

103 pancreatic and/or splenic surgical patients were enrolled including 52 PDAC, 10 borderline and 10 neuroendocrine tumors (NETs). Lymphocytes and IMCs were analysed by flow cytometry in blood, in spleen and in three PDAC cell conditioned (CM) or non conditioned PBMC. PDL1 and CTLA4 were studied in 30 splenic samples, in control and conditioned PBMC. IMCs were FACS sorted and co-coltured with allogenic T lymphocytes. In PDAC a reduction was found in circulating CD8(+) lymphocytes (p = 0.004) and dendritic cells (p = 0.01), which were reduced in vitro by one PDAC CM (Capan1; p = 0.03). Blood myeloid derived suppressive cells (MDSCs) CD33(+)CD14(-)HLA-DR(-) were increased in PDAC (p = 0.022) and were induced in vitro by BxPC3 CM. Splenic dendritic cells had a higher PDL1 expression (p = 0.007), while CD33(+)CD14(+)HLA-DR(-) IMCs had a lower CTLA4 expression (p = 0.029) in PDAC patients. In vitro S100A8/A9 complex, one of the possible inflammatory mediators of immune suppression in PDAC, induced PDL1 (p = 0.018) and reduced CTLA4 expression (p = 0.028) among IMCs. IMCs not expressing CTLA4 were demonstrated to be immune suppressive.

CONCLUSION

In PDAC circulating dendritic and cytotoxic T cells are reduced, while MDSCs are increased and this might favour tumoral growth and progression. The reduced CTLA4 expression found among splenic IMCs of PDAC patients was demonstrated to characterize an immune suppressive phenotype and to be consequent to the direct exposure of myeloid cells to pancreatic cancer derived products, S100A8/A9 complex in particular.

New screening tests enrich anti-transglutaminase results and support a highly sensitive two-test based strategy for celiac disease diagnosis

BACKGROUND

The identification of specific serological algorithms allowing the diagnosis of celiac disease (CD) is a new challenge for both the clinic and the laboratory. We compared the diagnostic accuracy of three new tests proposed for CD screening with that of the well established IgA tTG, and ascertained whether any combination of these tools might enhance accuracy in diagnosing CD.

METHODS

In sera from 329 CD and 374 control children, the following were assayed: IgA tTG; IgA/IgG, which identify tTG-gliadin complexes (Aeskulisa Celi Check and CeliCheck IgGA); IgA/IgG, which identify deamidated gliadin peptides and tTG (QUANTA Lite(TM) h-tTG/DGP Screen).

RESULTS

When specificity was set at 100%, the most sensitive index of CD was IgA tTG (75.7%, cut-off=100U), followed by QUANTA Lite(TM) h-tTG/DGP Screen (65.3%, cut-off 145U), Aeskulisa Celi Check (62.6%, cut-off 909U/mL) and CeliCheck IgGA (59.6%, cut-off 977U/mL). Three algorithms were obtained by combining IgA tTG with each of the new tests. The algorithm obtained by measuring IgA tTG and QUANTA Lite(TM) h-tTG/DGP Screen allowed the correct identification of CD in 78.7% of cases (negative predictive value=97.3%).

CONCLUSIONS

The two-test based strategy could be used for the cost effective diagnosis of CD.

VKORC1, CYP2C9 and CYP4F2 genetic-based algorithm for warfarin dosing: an Italian retrospective study

Aim: A total of 371 patients under stable warfarin therapy were retrospectively selected to develop a pharmacogenetic algorithm to identify the individual maintenance dose. Materials & methods: The variables that were entered into the algorithm were: VKORC1, CYP2C9 and CYP4F2 polymorphisms, body surface area and age. Results: The percentage of cases whose predicted mean weekly warfarin dose was within 20% of the actual maintenance dose was 51.8% considering patients overall, and were 36.2, 66.2 and 55.4%, respectively, taking into account patients requiring low (≤25 mg/week), intermediate (25–45 mg/week) and high (≥45 mg/week) doses. The algorithm could correctly assign 73.8 and 63.2% of patients to the low- and high-dose regimens, respectively. We developed and validated a pharmacogenetic algorithm in a series of Italian patients, we then tested, in the same series of italian patients, the formulas of three published algorithms. These three algorithms were developed and validated by their authors in a series of patients different from our own. The performance of our algorithm in our patients series was slightly higher than that achieved when using the three other algorithms in our patients series. Conclusion: The high predictive accuracy of low and high warfarin requirements of our algorithm warrants its application in prospective studies for clinical validation.

Pancreatic cancer biomarkers discovery by surface-enhanced laser desorption and ionization time-of-flight mass spectrometry

BACKGROUND

Surface-enhanced laser desorption and ionization time-of-flight mass spectrometry (SELDI-TOF/MS), a laboratory-friendly technique, is used to identify biomarkers for cancer. The aim of the present study was to explore the application of SELDI proteomic patterns in serum for distinguishing between cases of pancreatic cancer, chronic pancreatitis, type 2 diabetes mellitus and healthy controls.

METHODS

Sera from 12 healthy controls, 24 patients with type 2 diabetes mellitus, 126 with pancreatic cancer, including 84 with diabetes, and 61 with chronic pancreatitis, 32 of which were diabetics, were analyzed using SELDI-TOF/MS. Spectra (IMAC-30) were clustered and classified using Biomarker Wizard and Biomarker Pattern software.

RESULTS

Two decision tree classification algorithms, one with and one without CA 19-9, were constructed. In the absence of CA 19-9, the splitting protein peaks were: m/z 1526, 1211, and 3519; when CA 19-9 was used in the analysis, it replaced the m/z 3519 splitter. The two algorithms performed equally for classifying patients. A classification tree that considered diabetic patients only was constructed; the main splitters were: 1211, CA 19-9, 7903, 3359, 1802. With this algorithm, 100% of patients with type 2 diabetes mellitus, 97% with chronic pancreatitis and 77% of patients with pancreatic cancer were correctly classified. SELDI-TOF/MS features improved the diagnostic accuracy of CA 19-9 (AUC = 0.883 for CA 19-9; AUC = 0.935 for CA 19-9 and SELDI-TOF/MS features combined).

CONCLUSIONS

SELDI-TOF/MS allows identification of new peptides which, in addition to CA 19-9, enable the correct classification of the vast majority of patients with pancreatic cancer, which can be distinguished from patients with chronic pancreatitis or type 2 diabetes mellitus.

Antibodies against synthetic deamidated gliadin peptides for celiac disease diagnosis and follow-up in children

BACKGROUND

AGA IgA II and AGA IgG II have recently been suggested as reliable tools for celiac disease (CD) diagnosis. We compared their utility for diagnosis and monitoring CD in children with that of tTG IgA, an established CD marker.

METHODS

We studied a cohort of 161 CD and 129 control children in whom CD was histologically confirmed or ruled out. We followed 37 children with CD on a gluten-free diet for 12-84 months. In fasting sera, we measured AGA IgA II, AGA IgG II, and tTG IgA using ELISAs.

RESULTS

The best sensitivity (92.5%), specificity (97.6%), positive predictive value (98%), and negative predictive value (91.2%) were obtained using tTG IgA. AGA IgG II correctly identified 3 of 3 children with CD with total IgA deficiency who had negative AGA IgA II and tTG IgA results. In children <2 years old without total IgA deficiency, AGA IgG II and tTG IgA performed equally well (sensitivity 96.4% and specificity 100%). AGA IgA II, AGA IgG II, and tTG IgA concentrations diminished significantly (P < 0.0001) after 1 year of a gluten-free diet, reaching values below the cutoff in 87%, 70%, and 51% of cases, respectively.

CONCLUSIONS

The best available index for diagnosing CD in children was tTG IgA. In infants <2 years old, AGA IgG II performed as well as tTG IgA in cases without total IgA deficiency and allowed detection of CD when total IgA was <0.06 g/L. Gluten-free diet monitoring can be achieved using any of the studied serum markers.

Clinical relevance of Helicobacter pylori cagA and vacA gene polymorphisms

BACKGROUND & AIMS

The Helicobacter pylori gene cagA and s1 or m1 forms of vacA are more common in disease-associated strains. Recently, forms of cagA encoding multiple type C EPIYA segments (which increase phosphorylation-dependent CagA activity) and a new type i1 "intermediate region" polymorphism in vacA (which confers toxicity) have been described. We assessed the association of new and established cagA and vacA polymorphisms with disease.

METHODS

We studied 203 H pylori-infected subjects (53 gastric cancer [GC], 52 peptic ulcer [PU], and 98 gastritis). vacA signal, mid and intermediate region polymorphisms, cagA presence, and EPIYA-C segment number were analyzed by polymerase chain reaction.

RESULTS

cagA-positive strains were significantly associated with GC and PU (P < .001 and P < .05). GC risk was further associated with the number of cagA EPIYA-C segments (odds ratio [OR] = 7.37, 95% confidence interval [CI] = 1.98-27.48 for 1 EPIYA-C segment; OR = 32.5, 95% CI = 8.41-125.58 for 2 or more EPIYA-C segments). Increasing number of EPIYA-C segments also increased the risk of intestinal metaplasia. Type s1 and i1 vacA alleles were also associated with GC and type i1 vacA with PU (OR = 2.58, 95% CI = 1.19-5.61), including a significant association with duodenal ulcer. In multivariate analysis, the associations of cagA EPIYA-C segment number with GC and intestinal metaplasia as well as vacA i1 type association with PU remained.

CONCLUSIONS

We confirmed the associations of cagA and vacA polymorphisms with disease but now define their most important features. For cancer risk, among Western strains, the most important factor is the number of cagA EPIYA-C segment. For PU risk, it is the intermediate region type of vacA.

Clarithromycin resistance, tumor necrosis factor alpha gene polymorphism and mucosal inflammation affect H. pylori eradication success

Several bacterial and host-related factors concur in causing Helicobacter pylori eradication failure. We ascertained the role of bacterial virulence genes (cagA, vacA), clarithromycin resistance [Cla(R), 23S ribosomal RNA (rRNA) mutations], host polymorphism of CYP2C19 (polyphosphoinositide, PPI, metabolism) and of the cytokines IL-1B-31C>T, IL-1RN VNTR, IFN-gamma+874A>T, TNF-alpha-1031T>C, TNF-alpha-857C>T, TNF-alpha-376G>A, TNF-alpha-308G>A, TNF-alpha-238G>A, IL-10-1082A>G, IL-10-819C>T, IL-10-592C>A, IL-12A+6686G>A, IL-12B+15485A>C. Two groups of H. pylori-infected and H. pylori-treated patients were retrospectively identified: 45 not eradicated and 57 eradicated. Treatment failure was significantly correlated with Cla(R) (all resistant strains in non-eradicated patients); with TNF-alpha-238, IL10-819, IL10-592, IL-12B+15485 single nucleotide polymorphism (SNP); with IL10 ATA/ATA haplotype; and with antral inflammatory grade. On considering Cla(S)-infected patients only, logistic regression analysis (eradication = dependent; TNF-alpha-238, IL12B + 15485 genotypes, IL10 ATA/ATA as present or absent, antral gastritis grade = covariates) confirmed as significantly correlated with eradication antral gastritis grade only (Exp(B) = 6.48; 95% CI, 1.2-35.01). In conclusion, the bacterial determinant causing triple therapy failure is clarithromycin resistant, being virulence genes not involved. The host related factors that favor eradication are those linked to inflammation: a higher inflammatory infiltrate in the mucosa, possibly favored by genotypes able to down regulate the anti-inflammatory cytokine response, enhance the chance of eradication success.

Suicide gene therapy with the yeast fusion gene cytosine deaminase/uracil phosphoribosyltransferase is not enough for pancreatic cancer

OBJECTIVES

Suicide gene therapy with FCY1 gene, encoding cytosine deaminase (CD), together with FUR1, encoding uracil phosphoribosyltransferase (UPRT), has been proposed for pancreatic cancer therapy in vivo. We ascertained whether gene therapy with FCY1-FUR1 is effective in killing pancreatic cancer cells after 5-fluorocytosine (5-FC) treatment.

METHODS

AsPC1, BxPC3, Capan1, MIA PaCa2, and Panc1 cell lines were transfected using 2 plasmid vectors expressing CD only (pRSV-CD) or the chimera CD-UPRT (pRSV-CD-UPRT). Control and pRSV-CD- or pRSV-CD-UPRT-transfected cell lines were treated with 0, 0.1, 0.5, 1, 5, and 10 mM of 5-FC for 1, 3, 6, 8, 10, and 13 days.

RESULTS

FCY1 alone did not confer sensitivity to 5-FC. The CD-UPRT-transfected BxPC3 and Panc1 were sensitive to very low 5-FC doses (0.1 mM). 5-Fluorocytosine-sensitive transfected cell lines rapidly converted 5-FC into 5-fluorouracil, whereas the 5-FC resistant cell lines had an impaired 5-FC conversion.

CONCLUSIONS

Suicide gene therapy with the FCY1 gene alone was ineffective in the treatment of pancreatic cancer in vitro. The pRSV-CD-UPRT construct conferred 5-FC sensitivity to some pancreatic cancer cell lines. Therefore, the application in vivo of suicide gene therapy with FCY1 alone or in combination with the FUR1 gene is probably destined to fail.

DNA repair pathways and mitochondrial DNA mutations in gastrointestinal carcinogenesis

This work focuses on the main DNA repair pathways, highlighting their role in gastrointestinal carcinogenesis and the role of mitochondrial DNA (mtDNA), mutations being described in several tumor types, including those of the gastrointestinal tract. The mismatch repair (MMR) system is inherently altered in patients with hereditary non-polyposis colorectal cancer, and plays a role in carcinogenesis in a subset of sporadic colorectal, gastric and esophageal cancers. Alterations in homologous recombination (HR) and non-homologous end-joining (NHEJ) also contribute to the development of pancreatic cancer. Gene polymorphisms of some X-ray cross-complementing (XRCCs), cofactor proteins involved in the base excision repair pathway, have been investigated in relation to gastric, colorectal and pancreatic cancer. Yet only one polymorphism, XRCC1 Arg194Trp, appears to be involved in smoking-related cancers and in early onset pancreatic cancer. Although evidence in the literature indicates that mtDNA somatic mutations play a role in gastric and colorectal carcinogenesis, no sound conclusions have yet been drawn regarding this issue in pancreatic cancer, although an mtDNA variant at 16519 is believed to worsen the outcome of pancreatic cancer patients, possibly because it is involved in altering cellular metabolism.

A new indirect chemiluminescent immunoassay to measure anti-tissue transglutaminase antibodies

OBJECTIVES

Anti-tissue transglutaminase antibody (anti-tTG) determination using second-generation (human antigen) enzyme-linked immunoassays (ELISAs) is a very accurate test to diagnose celiac disease (CD). In this study, we compared 2 second-generation ELISAs (Celikey tTG; Pharmacia Diagnostics GmbH & Co, Freiburg, Germany, and QuantaLite; Inova Diagnostics, San Diego, CA) and antiendomysial antibodies (EMAs) with a new indirect chemiluminescence immunoassay (LIAISON tTG; DiaSorin S.p.A., Saluggia, Italy) in diagnosing and monitoring CD in children.

PATIENTS AND METHODS

Antiendomysial antibodies, anti-tTGs and total immunoglobulin A were measured in the sera of 103 control children, 101 children with histologically proven CD and 31 CD children on gluten-free diet (GFD).

RESULTS

Anti-tissue transglutaminase antibody mean levels were significantly higher in CD with respect to control or GFD children. The sensitivity value of EMAs, LIAISON tTG, Celikey tTG and QuantaLite in diagnosing CD was 97.7%, 97.0%, 94.1% and 98.0%, respectively, and the corresponding specificity values were 91.1%, 98.1%, 97.1% and 96.1%, respectively. The degree of mucosal destruction (Marsh criteria) was correlated with EMA semiquantification (P < 0.01) and with the circulating levels of anti-tTGs measured using LIAISON (P < 0.05) or QuantaLite (P < 0.01). Twenty-six CD children were followed up from 5 to 25 months after GFD. The circulating levels of anti-tTGs measured with any of the 3 assays significantly dropped after GFD.

CONCLUSIONS

Anti-tissue transglutaminase antibody determination with second-generation ELISAs is as effective as EMAs for CD diagnosis. The novel chemiluminescent method described in the present paper for the detection of anti-tTGs in the diagnosis of CD had the highest sensitivity and specificity values. The anti-tTG test correlates with the degree of mucosal destruction and is suitable for verifying patient compliance to dietary treatment.

Pancreatic cancer-derived S-100A8 N-terminal peptide: A diabetes cause?

BACKGROUND

Our aim was to identify the pancreatic cancer diabetogenic peptide.

METHODS

Pancreatic tumor samples from patients with (n=15) or without (n=7) diabetes were compared with 6 non-neoplastic pancreas samples using SDS-PAGE.

RESULTS

A band measuring approximately 1500 Da was detected in tumors from diabetics, but not in neoplastic samples from non-diabetics or samples from non-neoplastic subjects. Sequence analysis revealed a 14 amino acid peptide (1589.88 Da), corresponding to the N-terminal of the S100A8. At 50 nmol/L and 2 mmol/L, this peptide significantly reduced glucose consumption and lactate production by cultured C(2)C(12) myoblasts. The 14 amino acid peptide caused a lack of myotubular differentiation, the presence of polynucleated cells and caspase-3 activation.

CONCLUSIONS

The 14 amino acid peptide from S100A8 impairs the catabolism of glucose by myoblasts in vitro and may cause hyperglycemia in vivo. Its identification in biological fluids might be helpful in diagnosing pancreatic cancer in patients with recent onset diabetes mellitus.

Mitochondrial DNA D-loop in pancreatic cancer: somatic mutations are epiphenomena while the germline 16519 T variant worsens metabolism and outcome

We ascertained the frequency of mitochondrial DNA (mtDNA) D-loop region somatic mutations in pancreatic cancer (PC) and verified whether polymorphisms were linked to diagnosis, prognosis, and PC-associated diabetes mellitus (DM) in 99 PC cases, 42 chronic pancreatitis (CP) cases, 18 pancreatobiliary tract tumors, and 87 healthy control subjects (CSs). Tissue samples were obtained from 19 patients with PC and 5 with CP. The D-loop region was sequenced from all tissue samples and from blood DNA of the same patients and 12 CSs. D-loop somatic mutations were found in 3 PC tissue samples (16%). Four single nucleotide polymorphisms (SNPs; T152C, T16189C, T16519C, A73G), more frequently found in PC than in CS, were analyzed by denaturing high-performance liquid chromatography-restriction fragment length polymorphism using blood DNA as the starting template in all cases. The T allele of 16519 SNP correlated with DM. The survival of patients with PC correlated with tumor stage and grade and with DM at diagnosis. When survival analysis was performed considering only patients with locally advanced disease, the T allele of mtDNA 16519 SNP correlated with shorter life expectancy. mtDNA D-loop somatic mutations, rarely found in PC, cannot be considered causative events for this tumor type and probably are epiphenomena; the mtDNA D-loop 16519 variant, which worsens PC prognosis, seems to be a predisposing genetic factor for DM.

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.

Quantitative PSA mRNA determination in blood: a biochemical tool for scoring localized prostate cancer

OBJECTIVES

Our aim was to verify whether the quantitative determination of PSA mRNA in circulating cells is helpful in diagnosing and scoring localized prostate cancer (PC).

DESIGN AND METHODS

The study included 145 patients with benign prostatic hyperplasia (BPH), 138 with localized PC and 28 healthy controls (CS). PSA cDNA was amplified by real-time PCR from circulating mononuclear cells. Serum total and free PSA were determined. Prostate cancers were histologically scored according to the Gleason criteria.

RESULTS

The most sensitive index of PC was tPSA (70%), and the most specific was f/t PSA (80%). High PSA mRNA was found more frequently in PC patients with poorly differentiated (23.1%) than in those with well (4.5%) or moderately (4.3%) differentiated tumors.

CONCLUSIONS

tPSA and f/t PSA are the best available tools for discriminating between localized PC and BPH. The quantitative assessment of PSA mRNA in blood might be helpful in the biochemical grading of prostate cancer.

Decreased total lymphocyte counts in pancreatic cancer: an index of adverse outcome

OBJECTIVES

An impaired host immunity might concur in determining the dismal prognosis of patients with pancreatic cancer (PC). Our aim was to ascertain whether the immunophenotype pattern of blood lymphocytes in PC correlates with tumor stage, grade, or survival.

METHODS

We studied 115 patients with PC, 44 with chronic pancreatitis (CP), 23 with tumors of the pancreatico-biliary tract, and 34 healthy controls (CS). Survival data were available for 77 patients with PC. Lymphocyte subsets were determined by fluorescent activated cell sorter (FACS) analysis.

RESULTS

In patients with PC, total lymphocyte counts were lower than in CP or CS, and CD8 lymphocyte subset levels were higher with respect to CS. Lower circulating lymphocytes were found in advanced PC stages (IIB-IV; chi2 = 11.55, P < 0.05) compared with stages 0 to IIA. Cox regression analysis, made considering total lymphocyte counts and tumor stage as covariates, was found to be significant for both tumor stage (P < 0.001) and total lymphocyte counts (P < 0.05).

CONCLUSIONS

The reduction of total lymphocytes in blood is the main immunologic change in advanced PC. The survival of these patients depends mainly on tumor stage, but it is also affected by the number of circulating lymphocytes, suggesting that the immune system plays an important role in pancreatic adenocarcinoma immunosurveillance and immunoediting.

Pancreatic cancer-associated diabetes mellitus: an open field for proteomic applications

BACKGROUND

Diabetes mellitus is associated with pancreatic cancer in more than 80% of the cases. Clinical, epidemiological, and experimental data indicate that pancreatic cancer causes diabetes mellitus by releasing soluble mediators which interfere with both beta-cell function and liver and muscle glucose metabolism.

METHODS

We analysed, by matrix-assisted laser desorption ionization time of flight (MALDI-TOF), a series of pancreatic cancer cell lines conditioned media, pancreatic cancer patients' peripheral and portal sera, comparing them with controls and chronic pancreatitis patients' sera.

RESULTS

MALDI-TOF analysis of pancreatic cancer cells conditioned media and patients' sera indicated a low molecular weight peptide to be the putative pancreatic cancer-associated diabetogenic factor. The sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis of tumor samples from diabetic and non-diabetic patients revealed the presence of a 1500 Da peptide only in diabetic patients. The amino acid sequence of this peptide corresponded to the N-terminal of an S-100 calcium binding protein, which was therefore suggested to be the pancreatic cancer-associated diabetogenic factor.

CONCLUSIONS

We identified a tumor-derived peptide of 14 amino acids sharing a 100% homology with an S-100 calcium binding protein, which is probably the pancreatic cancer-associated diabetogenic factor.

Intron 2 [IVS2, T-C +4] HFE gene mutation associated with S65C causes alternative RNA splicing and is responsible for iron overload

A patient with congenital liver fibrosis revealed a high transferrin saturation index and iron overload on liver biopsy. He did not carry the most frequent HFE mutations: C282Y or H63D. Heterozygosity was detected for S65C. Unknown HFE mutations were also sought using a combined denaturing high performance liquid chromatography (DHPLC)/direct sequence approach and another point mutation, a transition T-C (nt 4910), at the fourth base of the donor splice site of intron 2 [HFE, intervening sequence (IVS) 2, T-C +4] was found. Family screening revealed that a daughter carried both S65C and [IVS2, T-C +4].

CONCLUSION

: The existence in our proband of a partly-altered HFE protein in the region encoded by exon 2 might be responsible for the histologically-demonstrated iron overload.

Maldi-TOF analysis of portal sera of pancreatic cancer patients: identification of diabetogenic and antidiabetogenic peptides

BACKGROUND

Pancreatic cancer (PC) associated diabetes mellitus (DM) might be consequent to the diabetogenic effects of tumour products, possibly acting via nitric oxide (NO). Our aims were: (1) to verify whether PC associated DM determines an increased hepatic NO and (2) using MALDI-TOF analysis, to evaluate the peptide composition of PC cell conditioned media (CM) and of portal sera from patients with PC with (n=7) or without (n=4) DM.

METHODS

In liver tissue homogenates of 23 patients with PC (n=17) or chronic pancreatitis (n=6) GAPDH mRNA and activity, glucose, lactate, nitrite and nitrate were assayed. MALDI-TOF analysis was performed in three PC cell lines CM, and in portal sera from patients with PC.

RESULTS

Higher GAPDH mRNA and nitrite were found in patients with than in patients without DM. In PC cell CM, only 9 among a total of 75 fragments identified, were tumour specific. One hundred seventy-three fragments were identified in the portal sera of patients: one was positively and six fragments were negatively correlated with DM.

CONCLUSIONS

Unlike liver GAPDH, NO appears to be involved in PC associated DM. In portal sera, the absence, rather than the presence, of specific fragments, appears to be correlated with the development of DM.

Non-invasive diagnosis of Helicobacter pylori infection: simplified 13C-urea breath test, stool antigen testing, or DNA PCR in human feces in a clinical laboratory setting?

OBJECTIVES

(1) To compare two stool antigen EIAs (HpSA, FemtoLab) and PCR of ureaseA and cagA in feces, with (13)C-urea breath test (UBT). (2) To ascertain whether a simplified UBT (breath collection time = 10 min) is as reliable as the standard assay (30 min).

DESIGN AND METHODS

Helicobacter pylori status was recorded in Group 1 (n = 187) by UBT, H. pylori stool antigen, ureA and cagA PCR in feces. UBT with 10, 20 and 30 min sampling was performed in Group 2 patients (n = 283).

RESULTS

The sensitivity and specificity of HpSA, FemtoLab, and ureA were 67% and 99%, 90% and 96%, 35% and 98%, respectively. cagA results were positive in 16/48 H. pylori-positive, and in 5/100 H. pylori-negative patients. The results of UBT with a 10- and 30-min sampling strictly overlapped.

CONCLUSION

UBT with 10 min breath collection and FemtoLab stool antigen assay are the most reliable non-invasive tests to diagnose H. pylori infection.

Helicobacter pylori infection in children and adults: a single pathogen but a different pathology

BACKGROUND

The aims of this retrospective study were to ascertain in large series of children and adults: the relationship of the infecting strain to gastric mucosal lesions; and the relationship of the infecting strain to its duodenal localization.

MATERIALS AND METHODS

We studied 307 and 604 consecutive children and adults. In gastric mucosal samples H. pylori was cultured, genotyped and histologically assessed, while inflammation, activity and intestinal metaplasia were graded. In a subset of 171 patients H. pylori ureaseA (ureA) and cagA genes were amplified (PCR) using mucosal biopsies from the duodenum.

RESULTS

H. pylori infection was diagnosed in 40 children and 308 adults. cagA was identified in 50% and 65.5% of infected children and adults. Antral activity was associated with the density of infecting bacteria (p <.001) and with cagA (p <.01). Intestinal metaplasia was correlated with cagA (p <.001). The ureA gene was found in 56 duodenal samples from 82 H. pylori positive patients. Duodenal H. pylori ureA was significantly more frequent in patients with duodenal diseases than in those without (p <.01), cagA positive strains being mainly involved in the infection of this anatomical area (p <.01).

CONCLUSIONS

A severe H. pylori-associated gastritis is more prevalent when the density of infecting bacteria is high and when cagA positive strains cause the infection. The most virulent cagA positive H. pylori colonizes not only the gastric, but also the duodenal mucosa, which can be directly damaged by the bacteria itself or by its products.

Retrovirus-mediated herpes simplex virus thymidine kinase gene transfer in pancreatic cancer cell lines: an incomplete antitumor effect

INTRODUCTION

The transfer of drug-susceptible (suicide) genes to tumor cells by retroviral or adenoviral vectors is a novel approach to the treatment of human tumors.

AIMS

To ascertain the antitumor effect of retroviral transduction of the pancreatic cancer cell lines MIA PaCa 2, CAPAN-1, PANC1, and PSN1 with the herpes simplex virus thymidine kinase (HSV-TK) gene.

METHODOLOGY

The vector carried a neoselectable marker gene, the human interleukin-2 gene, an internal ribosome entry coding site, and the region coding HSV-TK.

RESULTS

Twenty micromoles or less of ganciclovir did not modify nontransduced TK- cell growth, whereas > or =100 micromol completely inhibited TK- cell growth, indicating that this dosage is cytotoxic per se. The 4 TK- and the 4 transduced cell lines were treated daily with 0.001, 0.01, 0.1, 1, 10, and 20 micromol of ganciclovir for 13 days. CAPAN-1 cell growth was completely inhibited by 0.1 micromol of ganciclovir; higher doses were required to kill PANC1 (10 micromol) and PSN1 (20 micromol). MIA PaCa 2 cell growth decreased following a 20-micromol ganciclovir dosing. The bystander effect was great in the CAPAN-1 cell line and moderate in PANC1; no bystander effect was recorded in MIA PaCa 2 and PSN1 cell lines.

CONCLUSION

Gene therapy with HSV-TK for pancreatic cancer seems effective in only a limited number of tumor-derived cell lines, and this limits its application in vivo.

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.