Generation and characterization of nanobodies targeting human pepsinogens.

Human pepsinogens (mainly pepsinogen I and pepsinogen II) are the major inactive precursor forms of the digestive enzyme pepsin which play a crucial role in protein digestion. The levels and ratios of human pepsinogens have demonstrated potential as diagnostic biomarkers for gastrointestinal diseases, particularly gastric cancer. Nanobodies are promising tools for the treatment and diagnosis of diseases, owing to their unique recognition properties. In this study, recombinant human pepsinogens proteins were expressed and purified as immunized antigens. We constructed a VHH phage library and identified several nanobodies via phage display bio-panning. We determined the binding potency and cross-reactivity of these nanobodies. Our study provides technical support for developing immunodiagnostic reagents targeting human pepsinogens.

Postprandial kinetics of digestive function in rainbow trout (Oncorhynchus mykiss): genes expression, enzymatic activity and blood biochemistry as a practical tool for nutritional studies.

Postprandial kinetics of genes expression of gastric (chitinase, pepsinogen) and intestinal (alkaline phosphatase, maltase) digestive enzymes and nutrient transporters (peptide transporter 1, sodium-glucose transporter 1), Brush Border Membrane (BBM) enzymes activity (alkaline phosphatase, leucine aminopeptidase, maltase, saccharase) and blood biochemistry (triglycerides, cholesterol, protein, albumin, glucose, amino acids) through NMR spectroscopy, were investigated in rainbow trout (Oncorhynchus mykiss) fed a commercial aquafeed. For this purpose, fish were starved 72 h and digestive tract and blood were sampled before the meal and at 1.5, 3, 6, 9, 12, and 24 h after feeding (T0, T1.5, T3, T6, T9, T12 and T24). The postprandial kinetic showed that the expression of the genes involved in digestion and nutrient transport, the activity of BBM enzymes, and the presence of metabolites in blood were stimulated in different ways by the presence of feed in the digestive tract. The expression of most genes peaked 3 h after meal except gastric pepsinogen and maltase in distal intestine that peaked at T9 and T12, respectively. The activity of BBM enzymes were stimulated differently based on the intestine tract. The plasma proteins level increased from T1.5 until T9, while the other blood parameters unvariated during the postprandial period. This study supplied useful information about the physiological effects a single meal as a potential tool for planning nutritional studies involving the digestive functions.

Family-based Helicobacter pylori infection status and transmission pattern in central China, and its clinical implications for related disease prevention.

BACKGROUND: Helicobacter pylori (H. pylori) has characteristics of family cluster infection; however, its family-based infection status, related factors, and transmission pattern in central China, a high-risk area for H. pylori infection and gastric cancer, have not been evaluated. We investigated family-based H. pylori infection in healthy households to understand its infection status, related factors, and patterns of transmission for related disease prevention. AIM: To investigate family-based H. pylori infection status, related factors, and patterns of transmission in healthy households for related disease prevention. METHODS: Blood samples and survey questionnaires were collected from 282 families including 772 individuals. The recruited families were from 10 selected communities in the greater Zhengzhou area with different living standards, and the family members' general data, H. pylori infection status, related factors, and transmission pattern were analyzed. H. pylori infection was confirmed primarily by serum H. pylori antibody arrays; if patients previously underwent H. pylori eradication therapy, an additional 13C-urea breath test was performed to obtain their current infection status. Serum gastrin and pepsinogens (PGs) were also analyzed. RESULTS: Among the 772 individuals examined, H. pylori infection rate was 54.27%. These infected individuals were from 246 families, accounting for 87.23% of all 282 families examined, and 34.55% of these families were infected by the same strains. In 27.24% of infected families, all members were infected, and 68.66% of them were infected with type I strains. Among the 244 families that included both husband and wife, spouse co-infection rate was 34.84%, and in only 17.21% of these spouses, none were infected. The infection rate increased with duration of marriage, but annual household income, history of smoking, history of alcohol consumption, dining location, presence of gastrointestinal symptoms, and family history of gastric disease or GC did not affect infection rates; however, individuals who had a higher education level showed lower infection rates. The levels of gastrin-17, PGI, and PGII were significantly higher, and PGI/II ratio was significantly lower in H. pylori-infected groups than in H. pylori-negative groups. CONCLUSION: In our study sample from the general public of central China, H. pylori infection rate was 54.27%, but in 87.23% of healthy households, there was at least 1 H. pylori-infected person; in 27.24% of these infected families, all members were infected. Type I H. pylori was the dominant strain in this area. Individuals with a higher education level showed significantly lower infection rates; no other variables affected infection rates.

The gastric proton pump in gobiid and mudskipper fishes. Evidence of stomach loss?

Stomach loss has occurred independently multiple times during gnathostome evolution with notable frequency within the Teleostei. Significantly, this loss of acid-peptic digestion has been found to correlate with the secondary genomic loss of the gastric proton pump subunits (atp4a, atp4b) and pepsinogens/pepsins (pga, pgc). Gastric glands produce gastric juice containing the acid and pepsin and thus their presence is a hallmark feature of a digestive system capable of acid-peptic digestion. However, in gobiid fishes although oesogaster and gastric glands have been identified histologically, their functional significance has been questioned. In the present study we address whether the gastric proton pump is present and expressed in gastric glands of the goby Neogobius species (Gobiidae) and in members of the family Oxudercidae, a group of amphibious gobiid fishes commonly known as mudskippers (genera: Periophthalmus, Boleophthalmus, Periophthalmodon and Scartelaos). We confirmed the presence of gastric glands and have immunohistochemically localized gastric proton pump expression to these glands in Neogobius fluviatilis and Periophthalmus novemradiatus, Periophthalmus barbarus and Boleophthalmus boddarti. Genome analysis in Neogobius melanostomus, Periophthalmus magnuspinnatus, Scartelaos histophorus, Boleophthalmus pectinirostris, and Periophthalmodon schlosseri revealed the presence of both atp4a and atp4b subunit orthologues in all species in a conserved genomic loci organization. Moreover, it was possible to deduce that the complete open reading frame and the key functional amino acid residues are present. The conserved expression of the gastric proton pump provides clear evidence of the potential for gastric acid secretion indicating that acid digestion is retained in these gobiid fishes and not lost.

Enzymological characteristics of pepsinogens and pepsins purified from lizardfish (Saurida micropectoralis) stomach.

One major pepsinogen, PG-I, and two minor pepsinogens, PG-II and PG-III were purified from lizardfish stomach by ammonium sulfate precipitation and two chromatographic columns. The three purified PGs migrated as single bands in native-PAGE gels with molecular weights (MW) ranging from 36 to 38 kDa. Each PG was converted to pepsin (P) at pH 2.0, and the MW were determined as 32 kDa (for P-I), 31 kDa (for P-II) and 30 kDa (for P-III). The optimum pH and temperature of pepsins were 2.0-3.5, and 40-50 °C. All 3 pepsins were strongly inhibited by pepstatin A. Divalent cations slightly stimulated the pepsin activities, but ATP had no effect on the pepsins. Purified pepsins were effective in the hydrolysis of various proteins. Km and kcat of the three pepsins for hemoglobin hydrolysis were 107.64-276.61 µM and 18.30-32.68 s-1, respectively. The new pepsins have potential for use in protein food procession and modification.

Performance evaluation of four prediction models for risk stratification in gastric cancer screening among a high-risk population in China.

OBJECTIVE: Early detection of gastric cancer (GC) is a critical step for decreasing mortality. The aim of this study was to evaluate the performance of four prediction models for risk stratification in the screening of GC and precancerous lesions among a large, high-risk population in China. DESIGN: This study was a retrospective analysis of data from the Provincial Gastric Cancer Screening Program (Zhejiang, China) spanning the period between October 2016 and April 2019, in which 97,541 individuals from the urban areas of 10 cities in Zhejiang province, China participated in this program. Demographic and clinical characteristics data were collected, and serum pepsinogens I and II, gastrin-17, and anti-H. pylori IgG antibody were detected. Participants were asked to voluntarily undergo gastroscopy. The performance of the ABC method, new ABC method, Tu's prediction model, and Li's prediction model, which stratified participants into low-, medium- and high-risk subgroups, were evaluated using the area under the receiver-operating characteristic (ROC) curve (AUC) and Youden index. RESULTS: Among the participants, 6005 (3447 males and 2558 females, mean age of 58.35 years), voluntarily underwent gastroscopy. Overall, 72 (1.20%) GC cases (30 early and 42 advanced) and 2006 cases with precancerous lesions (270 atrophic gastritis, 1634 intestinal metaplasia, and 102 dysplasia/intraepithelial neoplasia) were identified. Notably, Li's prediction model achieved the greatest AUC and Youden index values (0.708 and 0.319, respectively) for predicting GC, and exhibited the greatest ability to detect precancerous lesions, especially intestinal metaplasia. CONCLUSION: Li's prediction model performs the best for risk stratification in the screening, detection, and diagnosis of GC and precancerous lesions, whereas the overall performance of the other three models is similar ( www.chictr.org.cn , ChiCTR2100043363).

Associations of atrophic gastritis and proton-pump inhibitor drug use with vitamin B-12 status, and the impact of fortified foods, in older adults.

BACKGROUND: Atrophic gastritis (AG) and use of proton pump inhibitors (PPIs) result in gastric acid suppression that can impair the absorption of vitamin B-12 from foods. The crystalline vitamin B-12 form, found in fortified foods, does not require gastric acid for its absorption and could thus be beneficial for older adults with hypochlorhydria, but evidence is lacking. OBJECTIVES: To investigate associations of AG and PPI use with vitamin B-12 status, and the potential protective role of fortified foods, in older adults. METHODS: Eligible participants (n = 3299) not using vitamin B-12 supplements were drawn from the Trinity-Ulster and Department of Agriculture cohort, a study of noninstitutionalized adults aged ≥60 y and recruited in 2008-2012. Vitamin B-12 status was measured using 4 biomarkers, and vitamin B-12 deficiency was defined as a combined indicator value < -0.5. A pepsinogen I:II ratio <3 was considered indicative of AG. RESULTS: AG was identified in 15% of participants and associated with significantly lower serum total vitamin B-12 (P < 0.001) and plasma holotranscobalamin (holoTC; P < 0.001), and higher prevalence of vitamin B-12 deficiency (38%), compared with PPI users (21%) and controls (without AG and nonusers of PPIs; 15%; P < 0.001). PPI drugs were used (≥6 mo) by 37% of participants and were associated with lower holoTC concentrations, but only in participants taking higher doses (≥30 mg/d). Regular, compared with nonregular, consumption of fortified foods (i.e., ≥5 and 0-4 portions/wk, respectively) was associated with higher vitamin B-12 biomarkers in all participants, but inadequate to restore normal vitamin B-12 status in those with AG. CONCLUSIONS: Older adults who have AG and/or use higher doses of PPIs are more likely to have indicators of vitamin B-12 deficiency. Fortified foods, if consumed regularly, were associated with enhanced vitamin B-12 status, but higher levels of added vitamin B-12 than currently provided could be warranted to optimize status in people with AG.

Objective Evidence of Gastro-Esophageal Reflux Disease is Rare in Patients with Autoimmune Gastritis.

BACKGROUND AND AIMS: Patients with autoimmune atrophic gastritis (AAG) often complain of acid reflux symptoms, despite the evidence of hypo-achlorhydria. Rome IV criteria are used to define functional esophageal disorders. Our aim was to characterize gastroesophageal reflux disease (GERD) phenotypes in patients with AAG. METHODS: Between 2017-2018, 172 AAG patients were evaluated at Gastro-Oncology outpatient clinic of University of Padua. Of them, 38 patients with reflux symptoms underwent high-resolution manometry (HRM) and multichannel intraluminal impedance-pH monitoring (MII-pH). Seventy-six AAG consecutive patients asymptomatic for gastroesophageal reflux were selected as age and gender matched controls. Serum biomarkers (pepsinogens, gastrin-17 and Helicobacter pylori antibodies), upper endoscopy, histology and clinical data were compared. RESULTS: Out of 38/172 (22%) AAG patients with reflux symptoms, 2/38 had a GERD diagnosis based on abnormal esophageal acid exposure and 6/38 had a major motility disorder (i.e. outflow obstruction). Among the 30/38 patients with normal endoscopic findings, 9/30 had reflux hypersensitivity, 19 functional heartburn, 1 functional globus, 1 functional chest pain according to the Rome IV criteria. Antral atrophy, advanced corpus atrophy and OLGA stage were more frequent in controls than in reflux patients (p=0.01, p=0.031, p=0.01, respectively). No differences were found for serum biomarkers and symptom presentation. Most of the patients received proton pump inhibitors (PPIs) treatment (87%), with a minority (34%) reporting clinical benefit. CONCLUSIONS: Reflux symptoms are relatively common in AAG patients, but a firm diagnosis of GERD is rare (5%), whereas most of the patients have a functional disorder. PPI treatment is mostly clinical ineffective and should not be largely indicated.

The panoramic picture of pepsinogen gene family with pan-cancer.

BACKGROUND: It is well known that pepsinogen (PGs), as an important precursor of pepsin performing digestive function, has a good correlation with the occurrence and development of gastric cancer and it is also known that ectopic PGs expression is related to the prognosis of some cancers. However, the panoramic picture of pepsinogen gene family in human cancer is not clear. This study focused on elucidating the expression profile, activated pathway, immune cells infiltration, mutation, and copy number variation of PGs and their potential role in human cancer. METHOD: Based on the next generation sequence data from TCGA, Oncomine, and CCLE, the molecular changes and clinical correlation of PGs in 33 tumor types were analyzed systematically by R language, including the expression, mutation, and copy number variation of PGs and their correlation with cancer-related signal transduction pathway, immune cell infiltration, and prognostic potential in different cancers. RESULTS: PGs expression profiles appear different in 33 tumors. The transcriptional expression of PGs was detected in 16 of all 33 tumors. PGC was highly expressed in cholangiocarcinoma, colon adenocarcinoma, rectum adenocarcinoma, uterine corpus endometrial carcinoma, bladder urothelial carcinoma and breast cancer, while decreased in stomach adenocarcinoma, kidney renal clear cell carcinoma, prostate adenocarcinoma, lung squamous cell carcinoma, and esophageal carcinoma. PGA3, PGA4, and PGA5 were expressed in most normal tissues, but decreased in cancer tissues. PGs expression was significantly related to the activation or inhibition of many signal transduction pathways, in which PGC and PGA5 are more likely to be associated with cancer-related pathways. PGC participated in 33 regulatory network pathways in pan-cancer, mainly distributed in stomach adenocarcinoma, esophageal carcinoma, and lung squamous cell carcinoma, respectively. PGC and PGA3 expression were significantly correlated with immune cell infiltration. The results of survival analysis showed that different PGs expression play significantly different prognostic roles in different cancers. PGC was correlated with poor survival in brain lower grade glioma, skin cutaneous melanoma, and higher survival in kidney renal clear cell carcinoma, acute myeloid leukemia, mesothelioma, and uveal melanoma. PGA4 was only associated with higher survival in kidney renal clear cell carcinoma. Genetic variation analysis showed that PGC gene often mutated in uterine corpus endometrial carcinoma and stomach adenocarcinoma had extensive copy number amplification in various tumor types. PGC expression was upregulated with the increase of copy number in cholangiocarcinoma, esophageal carcinoma, and kidney renal papillary cell carcinoma, while in stomach adenocarcinoma, PGC was upregulated regardless of whether the copy number was increased or decreased. CONCLUSIONS: PGs was expressed unevenly in a variety of cancer tissues and was related to many carcinogenic pathways and involved in the immune regulation. PGC participated in 33 regulatory pathways in human cancer. Different PGs expression play significantly different prognostic roles in different cancers. The variation of copy number of PGC gene could affect the PGC expression. These findings suggested that PGs, especially PGC have characteristic of broad-spectrum expression in multiple cancers rather than being confined to the gastric mucosa, which may made PGs be useful biomarkers for prediction/diagnosis/prognosis and effective targets for treatment in human cancer.

The Gastroprotective Effect of Small Molecule Oligopeptides Isolated from Walnut (Juglans regia L.) against Ethanol-Induced Gastric Mucosal Injury in Rats.

The study investigated the protective effect of walnut oligopeptides (WOPs) against ethanol-induced gastric injury using Sprague-Dawley (SD) rats. Rats were randomly divided into seven groups based on body weight (10/group), normal group, ethanol group, whey protein group (220 mg/kg body weight), omeprazole group (20 mg/kg body weight), and three WOPs groups (220, 440, 880 mg/kg body weight). After 30 days of treatment with WOPs, rats were given 5 ml/kg absolute ethanol by gavage to induce gastric mucosal injury. Gastric ulcer index (GUI) were determined and the following measured; gastric content pH, gastric mucin, endogenous pepsinogens (PG), prostaglandin E2 (PGE2), inflammatory cytokines, oxidative stress indicators, and the expression of apoptosis-related proteins were measured to evaluate the gastroprotective effect of WOPs. The results showed that the administration with WOPs markedly mitigated the hemorrhagic gastric lesions caused by ethanol in rats, and decreased the GUI, the gastric content pH, PG1, PG2, and NO levels, enhanced mucin and PGE2. Also, WOPs repressed gastric inflammation through the reduction of TNF-α, IL-6, IL-1ß and increase IL-10 levels, and revealed antioxidant properties with the enhancement of superoxide dismutase, glutathione, and catalase activity, while reduction of malondialdehyde. Moreover, WOPs treatment significantly down-regulated Bax, caspase-3 and nuclear factor-κB p65 (NF-κB p65) expression, while up-regulating the expression of Bcl-2 and inhibitor kappa Bα (IκBα) protein. These results indicated that WOPs have protective effects against ethanol-induced gastric mucosal injury in rats through anti-inflammatory, anti-oxidation, and anti-apoptosis mechanisms.

Long-term follow up of serum pepsinogens in patients with gastric cancer or dysplasia after Helicobacter pylori eradication.

BACKGROUND AND AIM: Few studies have evaluated the change in serum pepsinogen (sPG) levels after the eradication of Helicobacter pylori. The aim of this study was to evaluate the effect of H. pylori eradication on sPG levels in patients with gastric cancer/dysplasia in comparison to a control group. METHODS: We prospectively enrolled 368 patients with gastric cancer/dysplasia and 610 control subjects. H. pylori status and sPG levels were measured before and after eradication. The follow-up time points were classified as < 12, 12-23, 24-35, and ≥ 36 months. RESULTS: In 179 H. pylori-eradicated patients with gastric cancer/dysplasia and 168 control group subjects, sPG I significantly decreased, and the sPG I/II ratio significantly increased after eradication compared to baseline, and this improvement in sPG values was maintained during all follow-up time points. Significant differences in sPG I and the sPG I/II ratio were observed between the gastric cancer/dysplasia group and the control group < 24 months after eradication. However, these differences in sPG values disappeared after ≥ 24 months of follow up. Moreover, significant differences in the intestinal metaplasia grade were observed between these two groups before eradication until < 24 months after eradication. However, these differences in the intestinal metaplasia grade disappeared after ≥ 24 months of follow up in the corpus. CONCLUSION: The sPG values and intestinal metaplasia grade (corpus) in the gastric cancer/dysplasia group became similar to those in the control group at long-term follow up after H. pylori eradication. It might be related with the reduction of metachronous gastric neoplasm.

Clostridium difficile-associated disease and Helicobacter pylori seroprevalence: A case-control study.

BACKGROUND: Helicobacter pylori inhabits the stomach and causes persistent inflammation, with changes in gastric acidity. However, it is unclear whether the presence of H pylori plays a role in Clostridium difficile-associated disease (CDAD). The study's aim was to examine relationships of H pylori seroprevalence and serum pepsinogens (PGs), as markers of gastric inflammation, with CDAD. MATERIALS AND METHODS: A case-control study was conducted among 49 CDAD cases and 54 controls (median age 82 years). Using enzyme-linked immunosorbent assays, sera were tested for H pylori IgG antibody, and PGI and PGII levels. Helicobacter pylori-positive samples were tested for IgG antibody to recombinant cytotoxin-associated gene A (CagA) virulent protein. Logistic regression models were fitted. RESULTS: Cases and controls were comparable in age (P = .5) and sex distribution (females 62% vs 57%, P = .6). Helicobacter pylori IgG seroprevalence was 47%, of whom 23% were CagA seropositives. Among cases compared to controls, 43% vs 28% were H pylori seropositive but lacking CagA IgG antibody: adjusted odd ratio (OR) 3.43 (95% confidence intervals [CI] 1.29-9.10); 18% vs 4% were positive for CagA phenotype: adjusted OR 9.32 (95% CI 1.61-53.76). This association was not affected by PG levels. CONCLUSIONS: Helicobacter pylori infection, especially with CagA virulent phenotype, might predispose to C difficile infection in elderly patients.

Clinical correlation between serum pepsinogen level and gastric atrophy in gastric neoplasm.

BACKGROUND/AIMS: The relationship between the serum pepsinogen (sPG) level and changes in gastric mucosa has been well studied. Here, we evaluated the usefulness of sPG (I, II, I/II ratio) and intragastric pH as a biomarker of severe gastric atrophy in gastric neoplastic lesions. METHODS: A total of 186 consecutive Korean patients with gastric neoplastic lesions underwent endoscopic submucosal dissection (ESD) in this study. The serologic atrophy group had sPG I level ≤ 70 ng/mL and an sPG I/II ratio ≤ 3.0. Before ESD, overnight fasting venous blood and gastric juice samples were collected to measure the sPG level and intragastric pH. The degree of gastric atrophy was estimated by endoscopy, and the rapid urease test was performed to investigate Helicobacter pylori infection. RESULTS: Patients who met the criteria of serologic atrophy showed more severe endoscopic atrophic changes (61% vs. 18%, p = 0.000). Older patients and those with more atrophic changes at the gastric upper body demonstrated both a lower sPG I level and a lower PG I/II ratio and more severe endoscopic atrophy. The sPG I/II ratio was the lowest in low grade dysplasia than in high grade dysplasia and early gastric cancer (EGC) (p = 0.015). In addition, patients who tested negative for serologic atrophy and H. pylori showed the lowest intragastric pH (p = 0.000). CONCLUSION: A low sPG I level and a low I/II ratio were correlated with the severity of gastric atrophy in gastric neoplastic lesions, thus indicating it to be a sensitive biomarker of gastric precancerous lesions or EGC.

Serologic Profile of Antiparietal Cell Antibodies, Pepsinogens, and H. pylori and Risk of Upper Gastrointestinal Cancer: A Nested Case-Control Study in China.

BACKGROUND: Autoimmune gastritis is understudied and possibly associated with gastric noncardia adenocarcinoma (GNCA) and esophageal squamous cell carcinoma (ESCC) in Western populations when it presents as pernicious anemia. METHODS: A nested case-control study within a Chinese cohort included 100 ESCC, 200 gastric cardia adenocarcinoma (GCA), and 200 GNCA cases diagnosed between 1986 and 2001 and 400 controls. Serostatus of antiparietal cell antibodies (APCA), Helicobacter pylori antibodies, and pepsinogens were measured using commercial kits and serum collected at baseline. We used logistic regression to calculate odds ratios (OR) and 95% confidence interval (CI) for associations between serologic biomarkers and cancer risk adjusted for numerous potential confounders. RESULTS: There was an average interval of 8 years between baseline blood draw and cancer diagnosis. The baseline prevalence of APCA seropositivity was 10.0% and 14.5% in subjects who developed GCA and GNCA, respectively. APCA seropositivity was inversely associated with later development of GCA (OR = 0.42; 95% CI, 0.24-0.75), but not significantly associated with later development of GNCA (OR = 0.82; 95% CI, 0.50-1.36) or ESCC (OR = 1.05; 95% CI, 0.58-1.88). APCA seropositivity was significantly associated with low pepsinogen I/II ratios (OR = 3.69; 95% CI, 1.66-8.21), and individuals with low pepsinogen I/II ratios who were seronegative for APCA had the highest risk of both GCA and GNCA. CONCLUSIONS: APCA seropositivity measured years prior to diagnosis was associated with prevalent atrophic gastritis but inversely associated with incident GCA in this Chinese population. IMPACT: APCA may contribute to a growing list of serologic markers that can improve risk stratification for gastric cancer.

Helicobacter pylori infection, serum pepsinogens as markers of atrophic gastritis, and leukocyte telomere length: a population-based study.

BACKGROUND: Persistent infections that induce prolonged inflammation might negatively affect the leukocyte telomere length (LTL); however, the role in LTL of Helicobacter pylori (H. pylori) infection, which persistently colonizes the stomach, remains unknown. The study objective was to examine associations of sero-prevalence of H. pylori immunoglobulin G (IgG) antibody and serum pepsinogens (PGs), as markers of atrophic gastritis, with LTL. A cross-sectional study was performed among 934 Arab residents of East Jerusalem, aged 27-78 years, randomly selected from Israel's national population registry. Sera were tested for H. pylori IgG and PG levels by ELISA. LTL was measured by southern blots. Multiple linear regression models were fitted to adjust for sociodemographic and lifestyle factors. RESULTS: LTL decreased significantly with age (p < 0.001) and was shorter in men than women (p = 0.032). The mean LTL was longer in H. pylori sero-positive persons than negative ones: mean difference 0.13 kb (95% CI 0.02, 0.24), p = 0.016. Participants with atrophic gastritis (PGI < 30 µg/L or a PGI: PGII < 3.0) had shorter LTL than did those without: mean difference - 0.18 (95% CI - 0.32, - 0.04). The difference was of larger magnitude between persons who had past H. pylori infection (sero-negative to H. pylori IgG antibody) and atrophic gastritis, compared to those who were H. pylori sero-negative and did not have atrophic gastritis: mean difference - 0.32 kb (95% CI - 0.55, - 0.10). This association remained significant after adjustment for age, sex, and religiosity: beta coefficient - 0.21 kb (95% CI - 0.41, - 0.001), p = 0.049. The results were similar after further adjustment for lifestyle factors. In bivariate analysis, mean LTL was longer in physically active persons than non-active ones, and shorter in persons with than without obesity; however, these differences were diminished and were not significant in the multivariable model. CONCLUSIONS: H. pylori IgG sero-positivity per se was not related to reduced LTL. However, persons with past H. pylori infection (i.e., lacking H. pylori IgG serum antibody) and with serological evidence of atrophic gastritis, had a significantly shorter LTL than did those without atrophic gastritis.

Only serum pepsinogen I and pepsinogen I/II ratio are specific and sensitive biomarkers for screening of gastric cancer.

Purpose We aimed to determine optimal cut-off points of plasma levels of ghrelin and serum levels of pepsinogen I, II, and their ratio for screening of gastric cancer (GC). Methods Blood samples were taken from 41 patients with confirmed gastric cancer along with 82 patients without malignancy. Serum levels of pepsinogen I and II, plus plasma levels of acylated ghrelin were measured using commercial ELISA kits. Results The case group had significant lower plasma levels of ghrelin, pepsinogen I, and pepsinogen I/II ratio in comparison to the control group (P<0.001). In the control group, there was significant higher serum pepsinogen I (P=0.028) and pepsinogen II (P=0.003) and lower pepsinogen I/II ratio (P=0.020) in males versus females; significantly higher serum pepsinogen II (P=0.047) and lower pepsinogen I/II ratio (P=0.030) in overweight compared to normal weight patients; and significantly lower pepsinogen I/II ratio (P=0.030) in smokers versus non-smoker. In the case group, there was only significantly lower pepsinogen I (P=0.006) in males versus females, and significantly lower plasma ghrelin (P=0.017) in overweight compared to normal weight patients. The characteristic curve analysis indicated that pepsinogen I at a cut-off of 70.95 µg/L and pepsinogen I/II ratio at cut-off of 2.99, had good sensitivity and specificity. Conclusions Just serums levels of pepsinogen I and the ratio of pepsinogen I/II can be used as biomarker to screen GC.

Evaluation of serum markers for gastric cancer and its precursor diseases among high incidence and mortality rate of gastric cancer area.

BACKGROUND: Mongolia has the highest mortality rate of gastric cancer. The early detection of cancer and down-staging screening for high risk patients are essential. Therefore, we aimed to validate serum markers for stratifying patients for further management. METHODS: Endoscopy and histological examination were performed to determine high risk and gastric cancer patients. Rapid urease test, culture and histological tests were performed to diagnose Helicobacter pylori infection. Serum pepsinogen (PG) I and II and anti-H. pylori IgG were measured by ELISA. Receiver Operating Characteristic analysis was used to extract the best cut-off point. RESULTS: Totally 752 non-cancer and 50 consecutive gastric cancer patients were involved. The corpus chronic gastritis (72%: 36/50 vs. 56.4%: 427/752), corpus atrophy (42.0%: 21/50 vs. 18.2%: 137/752) and intestinal metaplasia (IM) (64.0%: 32/50 vs. 21.5%: 162/752) were significantly higher in gastric cancer than non-cancer patients, respectively. Therefore, corpus chronic gastritis, corpus atrophy and IM were considered as high risk disease. The best serum marker to predict the high risk status was PGI/II < 3.1 (sensitivity 67.2%, specificity 61%) and PGI/II further reduced to < 2.2 (sensitivity 66%, specificity 65.1%) together with PGI < 28 ng/mL (sensitivity 70%, specificity 70%) were the best prediction for gastric cancer. The best cut-off point to diagnose H. pylori infection was anti-H. pylori IgG > 8 U/mL. Multivariate analysis showed that anti-H. pylori IgG > 8 U/mL and PGI/II < 3.1 increased risk for high risk status and PGI/II < 3.1 remained to increase risk for gastric cancer. CONCLUSION: The serum diagnosis using PGI/II < 3.1 cut-off value is valuable marker to predict high risk patients for population based massive screening.

Changes in Helicobacter pylori Immunoglobulin G Levels and Gastric Mucosal Atrophy after Successful Eradication of Helicobacter pylori

BACKGROUND/AIMS: Limited information is available about the relationship between Helicobacter pylori (H. pylori) immunoglobulin (Ig) G and serum pepsinogen (pepsinogen [PG], a marker of gastric mucosal atrophy) concentrations after H. pylori eradication. MATERIALS AND METHODS: Eligible patients who underwent endoscopic submucosal dissection (ESD) for early gastric cancer from August 2007 to March 2013 in a tertiary-referral center, and whose serum H. pylori IgG and PG concentrations were measured at the time of performing ESD and one year post-ESD, were selected. Successful H. pylori eradication was achieved after ESD in all the patients. According to the decrease in serum H. pylori IgG concentration after bacterial eradication, the patients were categorized as group 1 (IgG concentration decreased by <50%), and group 2 (IgG concentration decreased by ≥50%). RESULTS: Of the 106 patients, 25 (23.6%) were classified into group 1 and 81 (76.4%) into group 2. One year after H. pylori eradication, the serum PG II concentration was significantly decreased in group 2 (12.46±8.18 vs. 8.28±6.11, P=0.024). Although the serum PG I/II ratio of group 2 was higher than that of group 1 (8.32±4.52 ng/mL vs. 6.39±4.04 ng/mL), the difference was not significant (P=0.058). One year after successful eradication, elevated serum PG I/II ratio was observed in 21 patients (84%) in group 1 and in 77 patients (95.1%) in group 2 (P=0.087). The mean serum PG I/II ratio was also elevated in both groups. Serum PG II concentration was significantly decreased in group 2. CONCLUSIONS: A notable decrease in the concentration of H. pylori IgG antibody after bacterial eradication might reflect gastric mucosal atrophy. However, our study showed no statistically significant difference.

A non-invasive method for the diagnosis of upper GI diseases.

Upper-GI diseases are one of the most relevant issue in primary care. Nowadays they are still responsible for about 100 million ambulatory care visits only in the US. The diagnosis of almost every upper-GI condition is still deputed to invasive tests such as upper gastrointestinal endoscopy, gastroesophageal manometry or radiography. The possibility of analysing serum markers like Pepsinogens I and II, produced by gastric mucosa, in order to assess the functional characteristics of the upper GI tract has spread itself since the 80's especially in the diagnosis of peptic ulcer. The discovery of Helicobacter pylori by Marshall and Warren in 1983 and the scientific consecration of its role in the pathogenesis of gastric cancer and peptic ulcer (crystallized in Peleo Correa's Cascade, 1992), led to an increase importance of non-invasive tests, raising the attention towards the assessment of both immunoglobulins anti-H.p. and Gastrin hormone produced by antral G cells, as an implementation of the panel of gastric markers. This narrative review aims to analyze the huge landscape of non-invasive tests for diagnosis of GI diseases, studying the literature of the recent years.

Non-invasive method for the assessment of gastric acid secretion.

Methods for the measure of gastric acid secretion include invasive and non-invasive tests. The gold-standard to measure the acid output is the collection of gastric after in basal condition (Basal Acid Output, B.A.O.) and after an i.m. injection of pentagastrin (Maximal Acid Output, M.A.O.). However, direct measurement of gastric acid production is out of order in clinical practice, but many GI symptoms are claimed to be related with acid disorders and empirically cured. Hypochlorhydria is associated with precancerous conditions such as chronic atrophic gastritis (CAG). Acid measurement with non-invasive methods (pepsinogens) is supported by international guidelines.