Designing and development of multi-epitope chimeric vaccine against Helicobacter pylori by exploring its entire immunogenic epitopes: an immunoinformatic approach.

BACKGROUND: Helicobacter pylori is a prominent causative agent of gastric ulceration, gastric adenocarcinoma and gastric lymphoma and have been categorised as a group 1 carcinogen by WHO. The treatment of H. pylori with proton pump inhibitors and antibiotics is effective but also leads to increased antibiotic resistance, patient dissatisfaction, and chances of reinfection. Therefore, an effective vaccine remains the most suitable prophylactic option for mass administration against this infection. RESULTS: We modelled a multi-chimera subunit vaccine candidate against H. pylori by screening its secretory/outer membrane proteins. We identified B-cell, MHC-II and IFN-γ-inducing epitopes within these proteins. The population coverage, antigenicity, physiochemical properties and secondary structure were evaluated using different in-silico tools, which showed it can be a good and effective vaccine candidate. The 3-D construct was predicted, refined, validated and docked with TLRs. Finally, we performed the molecular docking/simulation and immune simulation studies to validate the stability of interaction and in-silico cloned the epitope sequences into a pET28b(+) plasmid vector. CONCLUSION: The multiepitope-constructed vaccine contains T- cells, B-cells along with IFN-γ inducing epitopes that have the property to generate good cell-mediated immunity and humoral response. This vaccine can protect most of the world's population. The docking study and immune simulation revealed a good binding with TLRs and cell-mediated and humoral immune responses, respectively. Overall, we attempted to design a multiepitope vaccine and expect this vaccine will show an encouraging result against H. pylori infection in in-vivo use.

Heavy metal detoxification mechanisms by microalgae: Insights from transcriptomics analysis.

Heavy metal pollution in ecosystem is a global threat. The associated toxicity and carcinogenic nature of heavy metals/metalloids such as mercury, cadmium, lead, and arsenic are imposing a severe risk to both ecological diversity and human lives. Harnessing the adaptive feature of microalgae for remediating toxic heavy metal has reached a milestone in past few decades. Transcriptomics analyses have provided mechanistic insights to map the dynamics of cellular events under heavy metal stress, thus deciphering the strategic responses of microalgae. Here, the present review comprehensively addresses the elicited molecular responses of microalgae to detoxify the heavy metal stress. The review highlights the intricate role of biochemical components and signaling networks mediating stress responsive transitions of microalgae at physiological level. Furthermore, the differential gene expression signifying the transporters involved in uptake, distribution/sequestration, and efflux of heavy metal has also been reviewed. In a nutshell, this study provided a comprehensive understanding of the molecular mechanisms adopted by microalgae at transcriptome level to nullify the oxidative stress while detoxifying the heavy metals.

Elucidating the bioremediation mechanism of Scenedesmus sp. IITRIND2 under cadmium stress.

Cadmium (Cd) is a non-biodegradable pollutant that has become a global threat due to its bioaccumulation and biomagnification in higher trophic levels of the food chain. Green technologies such as phycoremediation is an emerging approach and possess edge over conventional methods to remediate Cd from the environment. The present investigation elucidates the adaptive mechanism of a freshwater microalga, Scenedesmus sp. IITRIND2 under Cd stress. The microalga showed excellent tolerance to Cd stress with IC50 value of ~32 ppm. The microalga showed phenomenal removal efficiency (~80%) when exposed to 25 ppm of Cd. Such a high uptake of Cd by the cells was accompanied with increased total lipid content (~33% of dry cell weight). Additionally, the elevated level of ROS, lipid peroxidation, glycine-betaine, and antioxidant enzymes evidenced the activation of efficient antioxidant machinery for alleviating the Cd stress. Further, analysis of the fatty acid methyl ester (FAME) presented a steady increase in saturated and polyunsaturated fatty acids with biodiesel properties complying the American and European fuel standards. The study proposes an integrated approach for bioremediation of toxic Cd using hyper-tolerant microalgal strains along with biodiesel production from the generated algal biomass.

Evaluation of Taenia solium cyst fluid-based enzyme linked immunoelectro transfer blot for Neurocysticercosis diagnosis in urban and highly endemic rural population of North India.

BACKGROUND: Neurocysticercosis (NCC) is infection by cestode Taenia solium/pork tapeworm. Sero-diagnosis of NCC is still a challenge. Radiological imaging (CT/MRI) are cost intensive, requires technical expertise and resource intensive. Hence, its availability is restricted in endemic zone. Existing Enzyme electro immune transfer blot (EITB) antigens are difficult to make and is not standardized for endemic population. Therefore, there is a definite need for easy and reliable EITB tool. METHODS: T. solium metacestode were harvested from naturally infected swine post slaughter. The cyst fluid/vesicular fluid was aspirated and processed with ultracentrifugation and immune blot was performed with this antigen. RESULTS: A total of 406 cases [rural 256 (NCC 78, seizures other than NCC 108 and healthy controls 70); urban 150 (NCC 41, seizures other than NCC 59 and healthy controls 50)] were enrolled. Positive EITB (detection of band <50 kDa) was significantly associated with NCC patients of urban population only (p < 0.001) but not in rural populations (p = 0.292). However, identification of 15 kDa band had significant association with NCC both in urban and rural populations with overall sensitivity of 91.5% and specificity of 91.6%. Presence of 35 kDa band was associated with multiple NCC (p < 0.001). The study shows that 15 kDa reactive band on EITB is highly sensitive and specific for diagnosis of NCC in endemic population. CONCLUSIONS: Presence of 35 kDa band on EITB was associated with infection by multiple cysticerci. The observations demand purification of cyst fluid antigens to develop simple and easy to execute test in field studies.

Development of multi-epitope chimeric vaccine against Taenia solium by exploring its proteome: an in silico approach.

Objective: Taenia solium is a neglected tropical disease; larvae of this parasite infect central nervous system i.e. Neurocysticercosis, and adults mature and survive into intestine i.e. Taeniasis. Globally more than 50 million people are at the risk of infection. This is one of the main etiological agents for onset of new early epilepsy in developing countries. However, there is no vaccine available to protect human from its infection. Hence, there is an urgent need for a good vaccine.Methods: We applied immune-informatics approach to design a multi-epitope chimeric vaccine consisting of both B and T-cell epitopes.Results: From the whole transcriptome of Taenia, we identified five suitable peptides present on cell membrane, epitope identification on these peptides were done by using various immunoinformatic software. Physiochemical properties were determined and the tertiary structure of vaccine was predicted, validated and refined, and to increase antigenicity we added linker to them. Best-modeled protein-complex was used for docking study with TLR1-2, TLR4, TLR3 and TLR7 and stability of molecular complex was determined by molecular dynamics simulation.Conclusions: Overall, we attempted to design an efficient subunit chimeric vaccine, which could stimulate humoral and cellular immune responses and could protect against both neurocysticercosis and taeniasis.

Neglected Agent Eminent Disease: Linking Human Helminthic Infection, Inflammation, and Malignancy.

Helminthic parasitic infection is grossly prevalent across the globe and is considered a significant factor in human cancer occurrence induced by biological agents. Although only three helminths (Schistosoma haematobium, Clonorchis sinensis, and Opisthorchis viverrini) so far have been directly associated with carcinogenesis; there are evidence suggesting the involvement of other species too. Broadly, human helminthiasis can cause chronic inflammation, genetic instability, and host immune modulation by affecting inter- and intracellular communications, disruption of proliferation-anti-proliferation pathways, and stimulation of malignant stem cell progeny. These changes ultimately lead to tumor development through the secretion of soluble factors that interact with host cells. However, the detailed mechanisms by which helminths introduce and promote malignant transformation of host cells are still not clear. Here, we reviewed the current understanding of immune-pathogenesis of helminth parasites, which have been associated with carcinogenesis, and how these infections initiate carcinogenesis in the host.

Quadruple Negative Breast Cancers (QNBC) Demonstrate Subtype Consistency among Primary and Recurrent or Metastatic Breast Cancer.

PURPOSE: Despite the availability of current standards of care treatments for triple negative breast cancer (TNBC), many patients still die from this disease. Quadruple negative tumors, which are TNBC tumors that lack androgen receptor (AR), represent a more aggressive subtype of TNBC; however, the molecular features are not well understood. METHODS: Immunohistochemistry of estrogen receptor (ER), progesterone receptor (PR), HER2, and AR was determined in 244 primary and 630 recurrent/metastatic site biopsies. Expression was correlated with a panel of 25 cancer-related genes and proteins by IHC and in situ hybridization (ISH). RESULTS: We observed that 80.2% (65 of 81) of primary TNBC tumors and 75.7% (159 of 210) of recurrent/metastatic TNBC tumors are QNBC. Bivariate fit analysis demonstrated that QNBC (n = 224) significantly (P < .03) correlated with younger aged patients at initial biopsy compared to AR positive TNBC patients (n = 51). In paired primary tissue samples and primary to recurrent/metastatic samples, at least 70% Luminal, HER2 enriched, and QNBC subtype did not change molecular profile. But, TNBC seems to be the "unstable" subtype. Within the total cohort, discordance in molecular profiles was identified in both synchronous (20%) and asynchronous (21%) intra-individual analyses. Irrespective of sample type, (Synchronous or Asynchronous), QNBC demonstrated higher concordant than TNBC. IHC and ISH results of the cancer related genes, demonstrated that gene/protein expression differ by molecular profile: TNBC (HR-/HER2-, AR+) and QNBC (HR-/HER2-, AR-). IHC in metastatic tumors, showed that the percentage of tumors positive of EGFR were higher, while PTEN and TLE3 were lower in QNBC compared to TNBC. CONCLUSION: Standard treatment of Breast Cancer (BC) relies on reliable assessment by IHC analysis of ER, PR, and HER2. Our analyses suggest that the heterogeneity of TNBC is at least partially associated with the presence or absence of AR expression, suggesting that QNBC should be considered as a clinically relevant BC subtype. IHC analysis of AR appears to be a practical assay to determine the most aggressive TNBC subtypes and identifies tumors that could benefit from available targeted therapies.

AR negative triple negative or "quadruple negative" breast cancers in African American women have an enriched basal and immune signature.

There is increasing evidence that Androgen Receptor (AR) expression has prognostic usefulness in Triple negative breast cancer (TNBC), where tumors that lack AR expression are considered "Quadruple negative" Breast Cancers ("QNBC"). However, a comprehensive analysis of AR expression within all breast cancer subtypes or stratified by race has not been reported. We assessed AR mRNA expression in 925 tumors from The Cancer Genome Atlas (TCGA), and 136 tumors in 2 confirmation sets. AR protein expression was determined by immunohistochemistry in 197 tumors from a multi-institutional cohort, for a total of 1258 patients analyzed. Cox hazard ratios were used to determine correlations to PAM50 breast cancer subtypes, and TNBC subtypes. Overall, AR-negative patients are diagnosed at a younger age compared to AR-positive patients, with the average age of AA AR-negative patients being, 49. AA breast tumors express AR at lower rates compared to Whites, independent of ER and PR expression (p<0.0001). AR-negative patients have a (66.60; 95% CI, 32-146) odds ratio of being basal-like compared to other PAM50 subtypes, and this is associated with an increased time to progression and decreased overall survival. AA "QNBC" patients predominately demonstrated BL1, BL2 and IM subtypes, with differential expression of E2F1, NFKBIL2, CCL2, TGFB3, CEBPB, PDK1, IL12RB2, IL2RA, and SOS1 genes compared to white patients. Immune checkpoint inhibitors PD-1, PD-L1, and CTLA-4 were significantly upregulated in both overall "QNBC" and AA "QNBC" patients as well. Thus, AR could be used as a prognostic marker for breast cancer, particularly in AA "QNBC" patients.

Molecular Neuro-Pathomechanism of Neurocysticercosis: How Host Genetic Factors Influence Disease Susceptibility.

Neurocysticercosis (NCC) is one of the most neglected tropical diseases among widely endemic neurological diseases. It is caused by cysticerci of Taenia solium. The clinical symptom for the outcome of infection and progression of disease is pleomorphic and its neuro-pathomechanism is still illusive. Identification of host genetic factors and their association with disease susceptibility is one of the most important areas of research towards personalized medicine in the era of omics. Several genes and their allelic variations had been identified to be associated with various neurological disorders; however, the information for parasitic diseases affecting the central nervous system is very limited. Both Th1 and Th2 arms of the immune system are reported to be active at different stages of T. solium infection in the brain. Recently, several papers had been published, where the role of host genetic makeup with NCC had been explored. Increased frequency of HLA-A28, HLA-B63, HLA-B58, TLR 4 Asp299Gly, sICAM-1 gene K469E, GSTM1, and GSTT1 were found to be associated with increased risk of NCC occurrence, while HLA-DQW2 and HLA-A11 were shown to be providing protection from disease. In this review, we have summarized these findings and analyzed the influence of host genetic polymorphism on the susceptibility/resistance of host to NCC.

Collectins, H-ficolin and LL-37 reduce influence viral replication in human monocytes and modulate virus-induced cytokine production.

Infiltrating activated monocytes are important mediators of damaging inflammation during influenza A virus (IAV) infection. We show that soluble respiratory proteins [collectins, surfactant proteins D (SP-D) and mannose binding lectin (MBL), H-ficolin and LL-37] inhibit replication of seasonal IAV in human monocytes. The collectins and H-ficolin also increased viral uptake by the cells, while LL-37 did not. H-ficolin was able to inhibit replication of the 2009 pandemic H1N1 strain (Cal09) in monocytes, but SP-D and LL-37 had significantly fewer inhibitory effects on this strain than on seasonal IAV. All of these proteins reduced IAV-induced TNF-α production, even in instances when viral replication was not reduced. We used modified recombinant versions of SP-D, MBL and ficolin to elucidate mechanisms through which these proteins alter monocyte interactions with IAV. We demonstrate the importance of the multimeric structure, and of binding properties of the lectin domain, in mediating antiviral and opsonic activity of the proteins. Hence, soluble inhibitors present in airway lining fluid may aid clearance of IAV by promoting monocyte uptake of the virus, while reducing viral replication and virus-induced TNF-α responses in these cells. However, SP-D and LL-37 have reduced ability to inhibit replication of pandemic IAV in monocytes.

Synergistic cell death in FLT3-ITD positive acute myeloid leukemia by combined treatment with metformin and 6-benzylthioinosine.

Current therapy for acute myeloid leukemia (AML) primarily includes high-dose cytotoxic chemotherapy with or without allogeneic stem cell transplantation. Targeting unique cellular metabolism of cancer cells is a potentially less toxic approach. Monotherapy with mitochondrial inhibitors like metformin have met with limited success since escape mechanisms such as increased glycolytic ATP production, especially in hyperglycemia, can overcome the metabolic blockade. As an alternative strategy for metformin therapy, we hypothesized that the combination of 6-benzylthioinosine (6-BT), a broad-spectrum metabolic inhibitor, and metformin could block this drug resistance mechanism. Metformin treatment alone resulted in significant suppression of ROS and mitochondrial respiration with increased glycolysis accompanied by modest cytotoxicity (10-25%). In contrast, 6-BT monotherapy resulted in inhibition of glucose uptake, decreased glycolysis, and decreased ATP with minimal changes in ROS and mitochondrial respiration. The combination of 6-BT with metformin resulted in significant cytotoxicity (60-70%) in monocytic AML cell lines and was associated with inhibition of FLT3-ITD activated STAT5 and reduced c-Myc and GLUT-1 expression. Therefore, although the anti-tumor and metabolic effects of metformin have been limited by the metabolic reprogramming within cells, the novel combination of 6-BT and metformin targets this bypass mechanism resulting in reduced glycolysis, STAT5 inhibition, and increased cell death.

Arginine-rich histones have strong antiviral activity for influenza A viruses.

While histones are best known for DNA binding and transcription-regulating properties, they also have antimicrobial activity against a broad range of potentially pathogenic organisms. Histones are abundant in neutrophil extracellular traps, where they play an important role in NET-mediated antimicrobial killing. Here, we show anti-influenza activity of histones against both seasonal H3N2 and H1N1, but not pandemic H1N1. The arginine rich histones, H3 and H4, had greater neutralizing and viral aggregating activity than the lysine rich histones, H2A and H2B. Of all core histones, histone H4 is most potent in neutralizing IAV, and incubation with IAV with histone H4 results in a decrease in uptake and viral replication by epithelial cells when measured by qRT-PCR. The antiviral activity of histone H4 is mediated principally by direct effects on viral particles. Histone H4 binds to IAV as assessed by ELISA and co-sedimentation of H4 with IAV. H4 also induces aggregation, as assessed by confocal microscopy and light transmission assays. Despite strong antiviral activity against the seasonal IAV strains, H4 was inactive against pandemic H1N1. These findings indicate a possible role for histones in the innate immune response against IAV.

Genetic polymorphism of cytochrome P450 (CYP) 1A1, CYP1A2, and CYP2E1 genes modulate susceptibility to gastric cancer in patients with Helicobacter pylori infection.

BACKGROUND: Activity of cytochrome P450 (CYP), a polymorphic carcinogen-activating enzyme, is exaggerated following Helicobacter pylori infection. We studied the role of CYP2E1, CYP1A2 (rs762551), and CYP1A1 (rs4646903) polymorphisms in association with H. pylori infection in gastric carcinogenesis. METHODS: Genotyping of CYP2E1 (96-bp insertion), CYP1A2 (164A to C), and CYP1A1 (3801C to T) was carried out in 88, 76, 53, and 170 patients with gastric cancer (GC), functional dyspepsia (FD), peptic ulcer (PU), and healthy controls (HC), respectively. Serum IgG antibody (all subjects), rapid urease test, and histology (GC, FD, and PU patients) were used to test for H. pylori. RESULTS: CYP2E1 gene polymorphism was more common among patients with GC than HC and PU [48/88 (54.5 %) vs. 67/170 (39.4 %); OR 1.9, 95 % CI 1.1-3.2, p = 0.016) and [PU 18/53 (34 %); OR 2.3 (1-4.7), p = 0.02]. CYP1A2 CC or CT genotypes was lower among patients with GC than HC [50/88 (56.8 %) vs. 120/170 (70.6 %); OR 0.54 (0.31-0.92), p = 0.023]. CYP1A1 polymorphism and CYP1A1-CYP1A2 haplotypes were comparable among different groups. CYP2E1 was also more common in patients with GC than HC and PU in the absence of H. pylori [33/60 (55 %) vs. 19/52 (36.5 %); OR 4 (1.5-11.4), p = 0.007 and PU 7/22 (31.8 %); OR 3.4 (1-11.6), p = 0.05]. CYP1A1 (CT + TT) was more common in patients with GC than PU in presence of H. pylori [17/26 (65.4 %) vs. 11/29 (38 %); OR 3.0 (1.03-9.3), p = 0.045]. CONCLUSIONS: The presence of CYP2E1 (96-bp insertion) is associated with increased risk of GC even in absence of H. pylori. CYP1A2 CC or CT is associated with reduced risk of GC.

Association of microsomal epoxide hydrolase exon 3 Tyr113His and exon 4 His139Arg polymorphisms with gastric cancer in India.

BACKGROUND: Microsomal epoxide hydrolase, an important phase II xenobiotic enzyme, exhibits polymorphisms at exon 3 (Tyr113His [T/C]) and exon 4 (His139Arg [A/G]), which modulate enzyme activity; this may affect susceptibility to cancers. We studied association between these polymorphisms and gastric cancer (GC). METHODS: In a prospective study, 77 patients with GC, 50 with peptic ulcer, and 160 healthy controls (HC) were genotyped for exon 3 (PCR-RFLP followed by sequencing) and exon 4 (PCR-RFLP). Helicobacter pylori was considered to be present if two of three tests (histology, rapid urease test, and IgG antibody) were positive. RESULTS: Tyr113His and His139Arg genotypes and haplotypes were comparable among groups. 113His carriers were commoner among H. pylori-negative patients with GC than HC (p-value = 0.019, odds ratio (OR) = 2.5, 95 % confidence interval (CI) = 1.2-5.4). Haplotype combination of exons 3 and 4 113Tyr-139Arg (TA) were associated with higher and reduced risk in patients with GC than HC in presence and absence of H. pylori (25 % vs. 11 %; p-value = 0.033, OR = 2.61, 95 % CI = 1.08-6.3 and 11.6 % vs. 28.7 %; p-value = 0.004, OR = 0.33, 95 % CI = 0.15-0.7, respectively). CONCLUSIONS: Though 113Tyr-139Arg was associated with GC in presence of H. pylori, in its absence, it appeared to be protective. Exon 3, 113His, however, was associated with GC even in absence of H. pylori infection.

The human cathelicidin LL-37 inhibits influenza A viruses through a mechanism distinct from that of surfactant protein D or defensins.

LL-37, the only human cathelicidin, is a cationic antimicrobial peptide with antibacterial and antifungal activity. LL-37 is released from neutrophil granules and produced by epithelial cells. It has been implicated in host defence against influenza A virus (IAV) in recent studies. We now demonstrate dose-related neutralizing activity of LL-37 against several seasonal and mouse-adapted IAV strains. The ability of LL-37 to inhibit these IAV strains resulted mainly from direct effects on the virus, since pre-incubation of virus with LL-37 was needed for optimal inhibition. LL-37 bound high-density lipoprotein (HDL), and pre-incubation of LL-37 with human serum or HDL reduced its antiviral activity. LL-37 did not inhibit viral association with epithelial cells as assessed by quantitative RT-PCR or confocal microscopy. This finding contrasted with results obtained with surfactant protein D (SP-D). Unlike collectins or human neutrophil defensins (HNPs), LL-37 did not induce viral aggregation under electron microscopy. In the electron microscopy studies, LL-37 appeared to cause disruption of viral membranes. LL-37 had additive antiviral activity when combined with other innate inhibitors like SP-D, surfactant protein A and HNPs. Unlike HNPs, LL-37 did not bind SP-D significantly. These findings indicate that LL-37 contributes to host defence against IAV through a mechanism distinct from that of SP-D and HNPs.

Human H-ficolin inhibits replication of seasonal and pandemic influenza A viruses.

The collectins have been shown to have a role in host defense against influenza A virus (IAV) and other significant viral pathogens (e.g., HIV). The ficolins are a related group of innate immune proteins that are present at relatively high concentrations in serum, but also in respiratory secretions; however, there has been little study of the role of ficolins in viral infection. In this study, we demonstrate that purified recombinant human H-ficolin and H-ficolin in human serum and bronchoalveolar lavage fluid bind to IAV and inhibit viral infectivity and hemagglutination activity in vitro. Removal of ficolins from human serum or bronchoalveolar lavage fluid reduces their antiviral activity. Inhibition of IAV did not involve the calcium-dependent lectin activity of H-ficolin. We demonstrate that H-ficolin is sialylated and that removal of sialic acid abrogates IAV inhibition, while addition of the neuraminidase inhibitor oseltamivir potentiates neutralization, hemagglutinin inhibition, and viral aggregation caused by H-ficolin. Pandemic and mouse-adapted strains of IAV are generally not inhibited by the collectins surfactant protein D or mannose binding lectin because of a paucity of glycan attachments on the hemagglutinin of these strains. In contrast, H-ficolin inhibited both the mouse-adapted PR-8 H1N1 strain and a pandemic H1N1 strain from 2009. H-ficolin also fixed complement to a surface coated with IAV. These findings suggest that H-ficolin contributes to host defense against IAV.

Nitric oxide-dependent CYP2B degradation is potentiated by a cytokine-regulated pathway and utilizes the immunoproteasome subunit LMP2.

CYP2B proteins in rat hepatocytes undergo NO-dependent proteolytic degradation, but the mechanisms and the reasons for the specificity towards only certain P450 (cytochrome P450) enzymes are yet unknown. In the present study we found that down-regulation of CYP2B proteins by the NO donor NOC-18 is accelerated by pretreatment of the hepatocytes with IL-1 (interleukin-1ß) in the presence of an NO synthase inhibitor, suggesting that an NO-independent action of IL-1 contributes to the lability of CYP2B proteins. The immunoproteasome subunit LMP2 (large multifunctional peptidase 2) was significantly expressed in hepatocytes under basal conditions, and IL-1 induced LMP2 within 6-12 h of treatment. CYP2B protein degradation in response to IL-1 was attenuated by the selective LMP2 inhibitor UK-101, but not by the LMP7 inhibitor IPSI. The results show that LMP2 contributes to the NO-dependent degradation of CYP2B proteins, and suggest that induction of LMP2 may be involved in the potentiation of this degradation by IL-1.

Association between gastric mucosal glutathione-S-transferase activity, glutathione-S-transferase gene polymorphisms and Helicobacter pylori infection in gastric cancer.

AIM: Helicobacter pylori infection, though common, leads to gastric cancer (GC) in less than 1% individuals, suggesting the role of host factors. We previously reported the role of glutathione-S-transferase (GST) polymorphisms, the gene encoding a carcinogen-detoxifying enzyme, in GC. This study was aimed to evaluate GST enzyme activity, GST polymorphism, glutathione (GSH) levels and H. pylori in patients with GC. METHODS: GST and GSH levels were estimated in gastric biopsies of 52 patients with GC, 37 functional dyspepsia (FD) and 39 peptic ulcer (PU), and correlated with H. pylori (ELISA) infection and GST polymorphisms. GST polymorphisms were separately analyzed in relationship to H. pylori in 82 GC, 72 FD, 53 PU and 89 healthy controls (HC). RESULTS: GST activity was lower in patients with GC in comparison to PU (p = 0.03), but GSH levels were comparable. GSTT1 null genotype (GSTT1*0) and simultaneous deletion of both GSTT1 and GSTM1 genes was associated with lower enzyme activity (p = 0.02 and 0.01, respectively). GST and GSH levels in H. pylori positive and negative patients with GC, FD and PU were comparable. Presence of H. pylori infection along with GSTT1*0 (p = 0.006) and GSTM1*0 (p = 0.05) was associated with lower enzyme activity. GSTT1*0 was associated with higher odds ratio (OR) of GC in presence of H. pylori (GC vs. HC: p = 0.02, OR 2.6 [95% CI = 1-6] vs. p = 0.7, 1.3 [0.4-5.0]; GC vs. PU: p = 0.04, OR 3 [95% CI = 1-9] vs. not applicable (OR could not be computed as frequency of GSTT1*0 in H. pylori negative patients with PU was zero)]. CONCLUSIONS: GC is associated with reduced GST activity. Odds ratio of GC associated with GSTT1*0 is enhanced in presence of H. pylori probably due to combined effect of both on enzyme activity.

Patients with Helicobacter pylori infection have less severe gastroesophageal reflux disease: a study using endoscopy, 24-hour gastric and esophageal pH metry.

BACKGROUND AND AIM: The relationship between gastroesophageal reflux disease (GERD) and Helicobacter pylori is controversial. We evaluated endoscopic, 24-h gastric and esophageal acid profile among patients with GERD in relation to H. pylori, as the latter might alter gastric acid secretion. METHODS: Patients with GERD (n = 123), who were not on acid-suppressive drugs, and had not received anti-H. pylori therapy, underwent gastroduodenoscopy and tests for H. pylori detection. Esophageal manometry, 24-h pH metry, serum pepsinogen-I (PG-I), PG-II and gastrin-17 ELISA were done in all these patients. Univariate and multivariate analyses were performed to assess independent predictors for erosive esophagitis (EE). RESULTS: Of 123 patients (mean age 40.5 [13.1] years, 85 [69.1%] men), 59 (47.9%) had H. pylori infection. EE was more common in H. pylori non-infected than infected (49 vs. 32, p < 0.001). Among patients older than 40 years, absence of H. pylori was associated with lower esophageal pH and longer reflux (p = 0.02 and p < 0.001, respectively). PG-I/PG-II ratio was lower in H. pylori infected subjects (p < 0.001). In patients with higher LA grade of esophagitis, elevated PG-I levels and PG-I/PG-II ratio were associated with more acidic stomach (p = 0.04 and p = 0.01, respectively). Multivariate analyses showed low gastrin-17 (p = 0.016), higher age (p = 0.013), hiatus hernia (p = 0.004) and absence of H. pylori (p = 0.03) were independent predictors for risk of EE. CONCLUSION: H. pylori infection is associated with less acidic stomach and less severe GERD. Low gastrin-17, higher age, hiatus hernia and absence of H. pylori were the best predictors for EE risk.

Serological assessment of gastric intestinal metaplasia and atrophy using pepsinogen-I, pepsinogen-II and gastrin-17 levels in a low incidence area of gastric cancer endemic for H. pylori infection.

BACKGROUND: Intestinal metaplasia (IM), a precursor of gastric cancer (GC), may be amenable to non-invasive assessment. AIMS: We evaluated the diagnostic utility of serum PG-I, PG-II, PG-I/PG-II ratio and gastrin-17 (G-17) to detect IM and atrophy. METHODS: The study was conducted at a tertiary care center located in low-incidence area of GC, endemic for H. pylori. The evaluation was designed as a prospective case-control study. Patients with GC and dyspepsia were evaluated by endoscopy, histology for IM (H&E, PAS and Alcian blue stains) and H. pylori (H&E and Giemsa stains), rapid urease test and IgG antibody (positive results in any two assays). Serum levels of PG-I, PG-II and G-17 were estimated using ELISA. RESULTS: Of the 98 patients with GC and 62 with dyspepsia, 35 (36%) and 9 (14%) had IM, respectively (p = 0.004). Patients with IM (n = 44) had lower PG-UPG-II ratio than those without IM (n = 116; median 4.4, 0.37-23.6 vs. 6.3, 0.19-38.6, respectively; p = 0.005). A cut-off value of PG-I/PG-II ratio of 6.0 had 64% sensitivity and 52% specificity for detecting IM (area under ROC curve 0.64). 26/44 (60%) patients with IM and 52/98 (53%) with GC had PG-I/PG-II ratio < 6. Serum G-17 was comparable among patients with and without IM. CONCLUSIONS: Though the PG-I/PG-II ratio was lower in patients with IM, only 60% had a lower ratio suggesting that this test and G-17 may not be useful to detect IM in low-incidence areas of GC, endemic for H. pylori infection.