Serum ghrelin as a marker of atrophic body gastritis in patients with parietal cell antibodies

Relevance of pepsinogen, gastrin, and endoscopic atrophy in the diagnosis of autoimmune gastritis

Simple objective modalities are required for evaluating suspected autoimmune gastritis (AIG). This cross-sectional study aimed to examine whether pepsinogen, gastrin, and endoscopic findings can predict AIG. The diagnostic performance of endoscopic findings and serology in distinguishing AIG was evaluated. AIG was diagnosed in patients (N = 31) with anti-parietal cell antibody and/or intrinsic factor antibody positivity and histological findings consistent with AIG. Non-AIG patients (N = 301) were seronegative for anti-parietal cell antibodies. Receiver operating characteristic curve analysis of the entire cohort (N = 332) identified an endoscopic atrophic grade cutoff point of O3 on the Kimura–Takemoto classification (area under the curve [AUC]: 0.909), while those of pepsinogen-I, I/II ratio, and gastrin were 20.1 ng/mL (AUC: 0.932), 1.8 (AUC: 0.913), and 355 pg/mL (AUC: 0.912), respectively. In severe atrophy cases (≥ O3, N = 58, AIG/control; 27/31), the cutoff values of pepsinogen-I, I/II ratio, and gastrin were 9.8 ng/mL (AUC: 0.895), 1.8 (AUC: 0.86), and 355 pg/mL (AUC: 0.897), respectively. In conclusion, endoscopic atrophy is a predictor of AIG. High serum gastrin and low pepsinogen-I and I/II ratio are predictors even in the case of severe atrophy, suggesting their usefulness when the diagnosis of AIG is difficult or as serological screening tests.

Validation of diagnostic strategies of autoimmune atrophic gastritis: A case report

BACKGROUND

Autoimmune atrophic gastritis (AAG) is a type of chronic gastritis that mainly affects the gastric corpus. Due to the lack of standard diagnostic criteria and overlaps with the courses of Helicobacter pylori-related atrophic gastritis, reports on the diagnostic strategy of AAG at an early stage are limited.

CASE SUMMARY

A 71-year-old woman with severe anemia was diagnosed with AAG. Endoscopic views and pathological findings showed the coexistence of normal mucosa in the gastric antrum and atrophic mucosa in the gastric fundus. Serological tests showed that anti-parietal cell antibodies and anti-intrinsic factor antibodies were both positive. Immunohistochemical results, which showed negative H⁺-K⁺ ATPase antibody staining and positive chromogranin A (CgA) staining, confirmed the mechanism of this disease. After vitamin B12 and folic acid supplementation, the patient recovered well.

CONCLUSION

Successful diagnosis of AAG includes serological tests, endoscopic characteristics, and immunohistochemistry for H⁺-K⁺ ATPase and CgA antibodies.

Intestinal Metaplasia Influencing the Density of Ghrelin Expressing Cells in Morbid Obese Patients

PURPOSE

The aim was to compare the density of ghrelin-expressing cells (GECs) in morbid obese patients with or without intestinal metaplasia (IM).

MATERIALS AND METHODS

The study included 48 patients out of 244 who underwent laparoscopic sleeve gastrectomy between 2015 and 2019. IM was detected in the sleeve gastrectomy specimens of 24 of these 244 patients. The study group consisted of all of the patients with IM. It was a case matched study. Matching factors were age and gender. Ghrelin was stained with a Leica semiautomatic immunohistochemical-staining machine. Stained preparations with ghrelin were subjected to light microscopic examination.

RESULTS

The number of GECs in cases with IM was significantly lower than the cases without IM (p = 0.001). The number of GECs was significantly higher in cases with chronic inactive superficial gastritis than cases with chronic active superficial gastritis (p = 0.033).

CONCLUSION

We found that there was a decrease in the number of GECs in the corpus and fundus of the stomach in cases with gastric IM as a contribution to the literature. IM cause a decrease in the number of GECs in the gastric oxyntic glands. In addition, chronic active superficial gastritis is also associated with a decrease in the number of GECs. We can say that the common feature of all of these factors may be gastric mucosal damage. Consequently, damage to the gastric mucosa appears to reduce the number of GECs.

Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (FTIR) and Artificial Neural Networks Applied to Investigate Quantitative Changes of Selected Soluble Biomarkers, Correlated with H. pylori Infection in Children and Presumable Consequent Delayed Growth

Helicobacter pylori infections causing gastroduodenal disorders are a common medical problem. The aim of this study was to determine the specific motives of infrared spectroscopy (IR) spectra of sera from H. pylori-infected and uninfected children applied to investigate quantitatively-selected soluble biomarkers correlated with H. pylori infection in children and presumable consequent delayed growth. Sera from 41 children infected with H. pylori (Hp(+)) and 43 uninfected (Hp(-)) under the care of the Polish Mother's Hospital in Lodz, Poland, were analyzed. The H. pylori status was confirmed by gastroscopy, ¹³C urea breath testing, and anti-H. pylori IgG antibodies. Infrared spectra were measured using an FTIR/FT-NIR Spectrum 400 spectrometer (PerkinElmer). The IR spectrum was measured in the wavenumber range 3000-750 cm^-1 and subjected to mathematical calculation of the first derivative. Based on the chi-square test, 10 wavenumbers of spectra correlating with H. pylori infection were selected for use in designing an artificial neural network. Ten parts of the IR spectra correlating with H. pylori infection were identified in the W2 and W3 windows associated mainly with proteins and the W4 window related to nucleic acids and hydrocarbons. Artificial neural networks for H. pylori infection were developed based on chemometric data. By mathematical modeling, children were classified towards H. pylori infection in conjunction with elevated levels of selected biomarkers in serum potentially related to growth retardation. The study concludes that IR spectroscopy and artificial neural networks may help to confirm H. pylori-driven growth disorders in children.

Relationship between atrophic gastritis, serum ghrelin and body mass index

OBJECTIVE

Atrophic gastritis may affect circulating ghrelin levels and, indirectly, body mass index. The aim of this study was to investigate the relationship between atrophic gastritis, focusing on autoimmune atrophic gastritis and advanced stages of atrophic gastritis, serum ghrelin levels and BMI.

METHODS

Sixty-three patients, of whom 18 had autoimmune atrophic gastritis, 27 non-autoimmune antrum and corpus atrophic gastritis, and 18 non-atrophic gastritis or antrum-limited atrophic gastritis (control group) were assessed. All participants underwent endoscopy with multiple gastric biopsies. Atrophic gastritis was diagnosed by histology, classified according to the Updated Sydney System and staged by the Operative Link on Gastritis Assessment (OLGA) Classification. Total serum ghrelin, body weight and height were measured.

RESULTS

Compared with control patients (144.6 ± 111 pg/ml), mean serum level of total ghrelin was higher in patients with autoimmune atrophic gastritis (226.08 ± 243.03 pg/ml, P = 0.65) and lower in those with both antrum and corpus atrophic gastritis (74.51 ± 37.38 pg/ml, P = 0.12), although differences were not statistically significant. Serum ghrelin decreased in patients with advanced OLGA stages of atrophic gastritis. In non-obese patients BMI was significantly lower in those with both antrum and corpus atrophic gastritis than in control patients (23.1 ± 1.8 vs. 24.5 ± 1.6, P = 0.01), also after adjustment for age and sex (P = 0.02); BMI was positively correlated with serum total ghrelin (r = 0.51, P < 0.001).

CONCLUSION

Advanced stages of atrophic gastritis, but not autoimmune atrophic gastritis, seem to be associated with lower serum levels of ghrelin and lower BMI. In non-obese patients, BMI was positively correlated with total serum ghrelin.

Autoimmune gastritis

Autoimmune gastritis (AIG) is an increasingly prevalent, organ-specific, immune-mediated disorder characterized by the destruction of gastric parietal cells, leading to the loss of intrinsic factor and reduced acid output. These alterations result in malabsorption of iron, vitamin B₁₂ (pernicious anaemia) and potentially other micronutrients. For several years, most studies have focused on pernicious anaemia only, generating confusion between the two entities. In AIG, the gastric proton pump, H⁺/K⁺ ATPase, is the major autoantigen recognized by autoreactive T cells. The T cell-dependent activation of B cells stimulates the production of anti-parietal cell antibodies, the serological hallmark of AIG. The role of Helicobacter pylori infection in activating or favouring the autoimmune process is still uncertain. Early histopathological alterations allowing a more precise and prompt recognition have recently been described. AIG is burdened by a substantial diagnostic delay as it can present with varied clinical signs including, among others, gastrointestinal symptoms and neuropsychiatric manifestations. In advanced stages, AIG might progress to neuroendocrine tumours and gastric adenocarcinoma. Management includes early detection through a proactive case-finding strategy, micronutrient supplementation and endoscopic surveillance. This Primer comprehensively describes the most important insights regarding the epidemiology, pathophysiology, diagnosis and management of AIG, focusing on the most controversial, outstanding issues and future directions.

The Relations Among Serum Ghrelin, Motilin and Gastric Emptying and Autonomic Function in Autoimmune Gastritis

BACKGROUND

Gastric emptying (GE) of solids is delayed and autonomic dysfunction is detected in autoimmune gastritis (AIG). The goals of this study were to: (1) compare serum levels of ghrelin and motilin in subjects with delayed and normal GE and (2) investigate whether circulating antimyenteric antibodies (CAA), serum ghrelin levels and motilin levels have any effect on autonomic function.

MATERIALS AND METHODS

Noninvasive cardiovascular reflex tests were used in order to evaluate the autonomic function. GE was evaluated by a standard 2-hour scintigraphic test. Serum ghrelin and motilin levels were tested by enzyme-linked immunosorbent assay and CAA were tested by immunofluorescence.

RESULTS

The serum ghrelin and motilin levels in the patients with delayed GE (n = 22) were significantly decreased compared to the normal GE patients (n = 19), (67.55 ± 8.81 versus 126.79 ± 25.81pg/mL, P < 0.001 and 279.59 ± 111.12 versus 500.42 ± 155.95pg/mL, respectively, P < 0.001). Whereas, the serum ghrelin and motilin levels in the patients with deranged autonomic function (n = 26) were significantly decreased compared to the patients with normal autonomic function (n = 15), (80.73 ± 28.46 versus 127.79 ± 28.06pg/mL, P < 0.001 and 316.92 ± 160.47 versus 490.20 ± 141.02pg/mL, P < 0.001, respectively).  None of the patients were positive for CAA.

CONCLUSIONS

Ghrelin and motilin levels in AIG subjects with delayed GE and deranged autonomic function were significantly decreased. The decrease in serum ghrelin and plasma motilin levels in AIG suggest their potential role in the delayed GE observed in these subjects.

Detection of gastric atrophy by circulating pepsinogens: A comparison of three assays

BACKGROUND

Circulating levels of pepsinogens have been used in high gastric cancer-risk Asian and European populations to triage endoscopic evaluation for more severe pathology. There are different analytic methods with uncertain correlations. We therefore compared diagnostic performance of three commonly used pepsinogen assays to detect histologically confirmed gastric atrophy.

METHODS

We tested plasma samples from adult patients with (n=50) and without (n=755) moderate or severe gastric corpus atrophy, as determined histologically by consensus of three expert pathologists. A single laboratory measured pepsinogens I (PgI) and II (PgII) using commercially available assays: two ELISA assays produced by Biohit (Finland) and Vector Best (Russia), and a latex agglutination assay from Eiken (Japan). Quantitative correlations were assessed by Spearman statistics. Receiver operating characteristic (ROC) curves vs histological diagnosis were calculated using both the manufacturers' and optimized cutoffs.

RESULTS

Pepsinogen levels were highly correlated among the assays (pairwise Rhos: PgI≥0.84, PgII≥0.87; all P-values<.01). Based on manufacturers' cutoffs, sensitivities, specificities and areas under the ROC curve for detecting moderate to severe histological corpus atrophy by PgI/PgII were 44%/91%/0.70, 56%/84%/0.76, and 52%/90%/0.77 for Biohit, Vector Best and Eiken, respectively. Cutoffs optimized by ROC or data mining analyses did not substantially improve test performance.

CONCLUSIONS

Commercial assays for pepsinogen have good relative agreement but are imperfect tests for clinical diagnosis of gastric atrophy.

IMPACT

Pepsinogen testing alone does not provide sufficient information for gastric cancer risk stratification. Future investigations should focus on other potential markers, in combination with pepsinogens.

Therapeutic Potential of Targeting the Ghrelin Pathway

Ghrelin was discovered in 1999 as the endogenous ligand of the growth-hormone secretagogue receptor 1a (GHSR1a). Since then, ghrelin has been found to exert a plethora of physiological effects that go far beyond its initial characterization as a growth hormone (GH) secretagogue. Among the numerous well-established effects of ghrelin are the stimulation of appetite and lipid accumulation, the modulation of immunity and inflammation, the stimulation of gastric motility, the improvement of cardiac performance, the modulation of stress, anxiety, taste sensation and reward-seeking behavior, as well as the regulation of glucose metabolism and thermogenesis. Due to a variety of beneficial effects on systems’ metabolism, pharmacological targeting of the endogenous ghrelin system is widely considered a valuable approach to treat metabolic complications, such as chronic inflammation, gastroparesis or cancer-associated anorexia and cachexia. The aim of this review is to discuss and highlight the broad pharmacological potential of ghrelin pathway modulation for the treatment of anorexia, cachexia, sarcopenia, cardiopathy, neurodegenerative disorders, renal and pulmonary disease, gastrointestinal (GI) disorders, inflammatory disorders and metabolic syndrome.

Atrophic and Metaplastic Progression in the Background Mucosa of Patients with Gastric Adenoma

BACKGROUND

In patients with adenoma, assessing premalignant changes in the surrounding mucosa is important for surveillance. This study evaluated atrophic and metaplastic progression in the background mucosa of adenoma or early gastric cancer (EGC) cases.

METHODS

Among 146 consecutive patients who underwent endoscopic resection for intestinal-type gastric neoplasia, the adenoma group included 56 patients with low-grade dysplasia and the ECG group included 90 patients with high-grade dysplasia or invasive carcinoma. For histology, 3 paired biopsies were obtained from the antrum, corpus lesser curvature (CLC), and corpus greater curvature (CGC). Serological atrophy was determined based on pepsinogen A (PGA), progastricsin (PGC), gastrin-17, and total ghrelin levels. Topographic progression of atrophy and/or metaplasia was staged using the operative link on gastritis assessment (OLGA) and operative link on gastric intestinal metaplasia assessment (OLGIM) systems.

RESULTS

Rates of moderate-to-marked histological atrophy/metaplasia in patients with adenoma were 52.7%/78.2% at the antrum (vs. 58.8%/76.4% in EGC group), 63.5%/75.0% at the CLC (vs. 60.2%/69.7% in EGC group), and 10.9%/17.9% at the CGC (vs. 5.6%/7.8% in EGC group). Serological atrophy indicated by PGA and PGC occurred in 23.2% and 15.6% of cases in the adenoma and ECG groups, respectively (p = 0.25). Mean serum gastrin-17 concentrations of the adenoma group and EGC group were 10.4 and 9.0 pmol/L, respectively (p = 0.54). Mean serum total ghrelin levels were 216.6 and 209.5 pg/mL, respectively (p = 0.71). Additionally, between group rates of stage III-IV OLGA and OLGIM were similar (25.9% vs. 25.0%, p = 0.90; 41.8% vs. 44.9%, p = 0.71, respectively).

CONCLUSIONS

Atrophic and metaplastic progression is extensive and severe in gastric adenoma patients. A surveillance strategy for metachronous tumors should be applied similarly for patients with adenoma or EGC.

Decrease of serum total ghrelin in extensive atrophic gastritis: comparison with pepsinogens in histological reference

OBJECTIVE

Ghrelin is mainly secreted by the gastric oxyntic mucosa and its production is impaired in chronic atrophic gastritis. This study aimed at evaluating how serum total ghrelin correlates with the extent of atrophy, and to compare its performance as a serologic marker with that of pepsinogen (PG).

MATERIAL AND METHODS

Data were collected from 154 patients with atrophic gastritis. The histological extent of atrophy was assessed by three paired biopsies from the antrum, corpus lesser curvature (CLC), and corpus greater curvature (CGC). Fasting serum concentrations of total ghrelin, pepsinogen I and II were measured. Regression analysis was performed to evaluate the factors associated with serum total ghrelin. The serologic performance was compared with that of pepsinogen using receiver-operating characteristic (ROC) curves.

RESULTS

The Helicobacter pylori infection rate was 85%, and extensive atrophic gastritis involving CGC was found in 24%. Serum total ghrelin was significantly decreased in patients with extensive CGC atrophy (median: 170.4 pg/mL, vs 201.1 pg/mL in patients without atrophy; p < 0.001), and its levels correlated with those of pepsinogen I and I/II ratio. The decrease of serum total ghrelin was independent of age, gender, body mass index (BMI), and H. pylori infection status. The sensitivity and specificity of serum total ghrelin in predicting extensive atrophy were 57% and 79%, respectively. The discriminatory ability was similar to that of pepsinogen I/II ratio (p = 0.612), and lower than that of pepsinogen I (p = 0.040).

CONCLUSIONS

Serum total ghrelin is decreased during extensive atrophy involving CGC. The serologic performance is lower than that of pepsinogen I.

Role of Helicobacter pylori infection on nutrition and metabolism

Helicobacter pylori (H. pylori) is a gram-negative pathogen that is widespread all over the world, infecting more than 50% of the world’s population. It is etiologically associated with non-atrophic and atrophic gastritis, peptic ulcer and shows a deep association with primary gastric B-cell lymphoma and gastric adenocarcinoma. Recently, the medical research focused on the modification of the gastric environment induced by H. pylori infection, possibly affecting the absorption of nutrients and drugs as well as the production of hormones strongly implicated in the regulation of appetite and growth. Interestingly, the absorption of iron and vitamin B12 is impaired by H. pylori infection, while infected subjects have lower basal and fasting serum levels of ghrelin and higher concentration of leptin compared to controls. Since leptin is an anorexigenic hormone, and ghrelin stimulates powerfully the release of growth hormone in humans, H. pylori infection may finally induce growth retardation if acquired very early in the childhood and in malnourished children. This review is focused on the nutritional effects of H. pylori infection, such as the reduced bioavailability or the malabsorbption of essential nutrients, and of gastrointestinal hormones, as well as on the relationship between H. pylori and the metabolic syndrome.

Ghrelin gene products in acute and chronic inflammation

Ghrelin gene products--the peptides ghrelin, unacylated ghrelin, and obestatin--have several actions on the immune system, opening new perspectives within neuroendocrinology, metabolism and inflammation. The aim of this review is to summarize the available evidence regarding the less known role of these peptides in the machinery of inflammation and autoimmunity, outlining some of their most promising therapeutic applications.

Role of ghrelin in the pathophysiology of gastrointestinal disease

Ghrelin is a 28-amino-acid peptide that plays multiple roles in humans and other mammals. The functions of ghrelin include food intake regulation, gastrointestinal (GI) motility, and acid secretion by the GI tract. Many GI disorders involving infection, inflammation, and malignancy are also correlated with altered ghrelin production and secretion. Although suppressed ghrelin responses have already been observed in various GI disorders, such as chronic gastritis, Helicobacter pylori infection, irritable bowel syndrome, functional dyspepsia, and cachexia, elevated ghrelin responses have also been reported in celiac disease and inflammatory bowel disease. Moreover, we recently reported that decreased fasting and postprandial ghrelin levels were observed in female patients with functional dyspepsia compared with healthy subjects. These alterations of ghrelin responses were significantly correlated with meal-related symptoms (bloating and early satiation) in female functional dyspepsia patients. We therefore support the notion that abnormal ghrelin responses may play important roles in various GI disorders. Furthermore, human clinical trials and animal studies involving the administration of ghrelin or its receptor agonists have shown promising improvements in gastroparesis, anorexia, and cancer. This review summarizes the impact of ghrelin, its family of peptides, and its receptors on GI diseases and proposes ghrelin modulation as a potential therapy.

Adipocytokines in thyroid dysfunction

Adipocytokines are important mediators of interorgan crosstalk in metabolic regulation. Thyroid diseases have effects on metabolism and inflammation. The mechanism of these effects is not clear. Recently, there are several reports suggesting this interrelation between adipocytokines and thyroid dysfunction. In this review, we summarize this relation according to the literature.

Influence of Helicobacter pylori eradication on ghrelin levels in patients with chronic gastritis

AIM: To investigate the effect of Helicobacter pylori (H. pylori) eradication on the levels of ghrelin in serum and gastric mucosa in patients with chronic gastritis.

METHODS: Forty-two patients with chronic atrophic gastritis (CAG), 40 patients with chronic superficial gastritis (CSG), and 40 normal controls were included in the study. Serum ghrelin levels were measured by ELISA and expression of ghrelin in gastric muscosa was detected by RT-PCR in these patients before and after H. pylori eradication.

RESULTS: Serum ghrelin levels in H. pylori-infected patients with CSG or CAG were significantly lower than those in normal controls (25.58 μg/L ± 8.17 μg/L, 18.59 μg/L ± 8.19 μg/L vs 29.27 μg/L ± 7.58 μg/L; both P < 0.01). The expression of gastric mucosa-associated ghrelin in the two patient groups was also lower than that in the control group (0.86 ± 0.26, 0.75 ± 0.22 vs 1.06 ± 0.31, both P < 0.01). Four weeks after H. pylori eradication treatment, serum ghrelin level (29.10 μg/L ± 8.79 μg/L) and expression of gastric mucosa-associated ghrelin (1.10 ± 0.32) were significantly increased in the CSG group (both P < 0.01). However, there was no obvious difference in ghrelin levels in the CAG group between before and after H. pylori eradication treatment.

CONCLUSION: H. pylori-infected patients with chronic gastritis have decreased ghrelin levels. H. pylori eradication treatment increases ghrelin levels in patients with CSG, but not in those with CAG.

Cutting edge issues in autoimmune gastritis

Autoimmune gastritis is the outcome of a pathological CD4 T cell-mediated autoimmune response directed against the gastric H/K-ATPase. Silent initially, the gastric lesion becomes manifest in humans by the development of megaloblastic pernicious anemia arising from vitamin B12 deficiency. Cutting edge issues in this disease relate to its epidemiology, immunogenetics, a role for Helicobacter pylori as an infective trigger through molecular mimicry, its immunopathogenesis, associated organ-specific autoimmune diseases, laboratory diagnosis, and approaches to curative therapy.

Ghrelin in gastrointestinal disease

Enteroendocrine cells of the gastric fundus are the predominant source of ghrelin production, although ghrelin gene transcripts and ghrelin-producing cells have been identified throughout the gastrointestinal tract. Various infectious, inflammatory and malignant disorders of the gastrointestinal system have been shown to alter ghrelin production and secretion and consequently to affect endocrine ghrelin levels and activity. Animal studies have demonstrated that ghrelin and synthetic ghrelin mimetics can reduce the severity of gastric and colonic inflammation and human clinical trials are underway to determine the efficacy of ghrelin in improving motility disorders. This review summarises the impact of gastrointestinal disease on ghrelin synthesis and secretion and the potential use of ghrelin and its mimetics for the treatment of these diseases.

How to assess the severity of atrophic gastritis

Atrophic gastritis, is the main consequence of long-standing Helicobacter pylori infection, and is linked to the development of gastric cancer. The severity of atrophic gastritis is related to the lifetime risk of gastric cancer development, especially in terms of its degree and extent of mucosal damage. Therefore, it is important for clinicians to assess the severity of atrophic gastritis, interfere with the disease progress, and reverse gastric mucosal atrophy. In the article, we demonstrated some methods (conventional endoscopy, modern endoscopic technology and noninvasive methods) that may help assess the severity of atrophic gastritis and select the reasonable treatment protocols.

Endocrine impact of Helicobacter pylori: Focus on ghrelin and ghrelin o-acyltransferase

Ghrelin is predominantly produced by the gastric enteroendocrine cell compartment and is octanoylated by the recently discovered ghrelin o-acyltransferase (GOAT) before secretion into the bloodstream. This octanoylation is essential for many of the biological properties of ghrelin including appetite stimulation and anti-inflammatory properties as only the acylated form of ghrelin binds to the ghrelin receptor, the growth hormone secretagogue receptor (GHS-R). Given the gastric location of ghrelin production, it is perhaps not surprising that insult to the gastric mucosa affects circulating ghrelin levels in humans. Helicobacter pylori (H. pylori) infects more than fifty percent of the world’s population and once established within the gastric mucosa, can persist for life. Infection is associated with chronic gastritis, gastric atrophy and ulceration, reduced appetite and a lower body mass index (BMI). The large majority of studies investigating levels of circulating ghrelin and ghrelin expression in the stomach in patients with H. pylori infection indicate that the bacterium has a negative impact on ghrelin production and/or secretion. Eradication of infection restores ghrelin, improves appetite and increases BMI in some studies, however, a causative relationship between H. pylori-associated serum ghrelin decline and food intake and obesity has not been established. Most studies measure total ghrelin in the circulation although the measurement of the ratio of acyl/total ghrelin gives a clearer indication that the ghrelin acylation process is altered during infection and atrophy. GOAT is essential for the production of biologically-active, acyl ghrelin and the impact of H. pylori on GOAT expression and activity will be highly informative in the future.

Ghrelin and gastrin in advanced gastric cancer before and after gastrectomy

AIM: To investigate plasma ghrelin, gastrin and growth hormone secretagogue receptor (GHS-R) expression in advanced gastric cancer (GC) before and after resection.

METHODS: Seventy subjects in whom endoscopy of the upper gastrointestinal tract was performed in the Department of General Surgery at Cracow University during the past decade: (1) 25 patients with GC associated with Helicobacter pylori (H. pylori) infection; (2) 10 patients with GC 4-5 years after (total or subtotal) gastrectomy; (3) 25 healthy H. pylori-negative controls, matched by age and BMI to the above two groups; and (4) 10 GC patients 4-5 years after total gastrectomy. Ghrelin and gastrin plasma concentrations were measured by specific radioimmunoassay under fasting conditions and postprandially at 60 and 90 min after ingestion of a mixed meal. GHS-R expression was examined in biopsy samples from intact healthy mucosa and GC tissue using semi-quantitative reverse transcription-polymerase chain reaction.

RESULTS: In healthy controls, fasting plasma ghrelin levels were significantly elevated and declined markedly at 60 and 90 min after a mixed meal. The concomitant enhanced ghrelin, GHS-R and gastrin expression in GC tissue over that recorded in intact mucosa, and the marked rise in plasma gastrin in these subjects under fasting conditions indicate the role of these hormonal factors in GC formation. Fasting plasma levels and postprandial response of ghrelin and gastrin appear to be inversely correlated in healthy subjects. Feeding in the controls resulted in a significant fall in plasma ghrelin with a subsequent rise in plasma gastrin, but in H. pylori-positive GC patients submitted to total or distal gastrectomy, feeding failed to affect significantly the fall in plasma ghrelin that was recorded in these patients before surgery. Fasting ghrelin concentrations were significantly lower in patients 4-5 years after total gastrectomy compared to those in healthy controls and to these in GC patients before surgery.

CONCLUSION: Elevated plasma gastrin and suppression of fasting ghrelin in patients with GC suggest the existence of a close relationship between these two hormones in gastric carcinogenesis.

Helicobacter pylori infection and circulating ghrelin levels - a systematic review

BACKGROUND

The nature of the association between ghrelin, an orexigenic hormone produced mainly in the stomach, and Helicobacter pylori (H pylori), a bacterium that colonises the stomach, is still controversial. We examined available evidence to determine whether an association exists between the two; and if one exists, in what direction.

METHODS

We reviewed original English language studies on humans reporting circulating ghrelin levels in H pylori infected and un-infected participants; and circulating ghrelin levels before and after H pylori eradication. Meta-analyses were conducted for eligible studies by combining study specific estimates using the inverse variance method with weighted average for continuous outcomes in a random effects model.

RESULTS

Seventeen out of 27 papers that reported ghrelin levels in H pylori positive and negative subjects found lower circulating ghrelin levels in H pylori positive subjects; while 10 found no difference. A meta-analysis of 19 studies with a total of 1801 participants showed a significantly higher circulating ghrelin concentration in H pylori negative participants than in H pylori positive participants (Effect estimate (95%CI) = -0.48 (-0.60, -0.36)). However, eradicating H pylori did not have any significant effect on circulating ghrelin levels (Effect estimate (95% CI) = 0.08 (-0.33, 0.16); Test for overall effect: Z = 0.67 (P = 0.5)).

CONCLUSIONS

We conclude that circulating ghrelin levels are lower in H pylori infected people compared to those not infected; but the relationship between circulating ghrelin and eradication of H pylori is more complex.

Helicobacter pylori infection and circulating ghrelin levels - a systematic review

Background

The nature of the association between ghrelin, an orexigenic hormone produced mainly in the stomach, and Helicobacter pylori (H pylori), a bacterium that colonises the stomach, is still controversial. We examined available evidence to determine whether an association exists between the two; and if one exists, in what direction.

Methods

We reviewed original English language studies on humans reporting circulating ghrelin levels in H pylori infected and un-infected participants; and circulating ghrelin levels before and after H pylori eradication. Meta-analyses were conducted for eligible studies by combining study specific estimates using the inverse variance method with weighted average for continuous outcomes in a random effects model.

Results

Seventeen out of 27 papers that reported ghrelin levels in H pylori positive and negative subjects found lower circulating ghrelin levels in H pylori positive subjects; while 10 found no difference. A meta-analysis of 19 studies with a total of 1801 participants showed a significantly higher circulating ghrelin concentration in H pylori negative participants than in H pylori positive participants (Effect estimate (95%CI) = -0.48 (-0.60, -0.36)). However, eradicating H pylori did not have any significant effect on circulating ghrelin levels (Effect estimate (95% CI) = 0.08 (-0.33, 0.16); Test for overall effect: Z = 0.67 (P = 0.5)).

Conclusions

We conclude that circulating ghrelin levels are lower in H pylori infected people compared to those not infected; but the relationship between circulating ghrelin and eradication of H pylori is more complex.

Prevalence of parietal cell antibodies in a large cohort of patients with autoimmune thyroiditis

BACKGROUND

Autoimmune thyroiditis (AIT) may be associated with other organ-specific autoimmune disorders, including autoimmune gastritis, but the prevalence of this association is not entirely quantified. The aim of this study was to investigate the prevalence of parietal cell antibodies (PCA) in a large cohort of consecutive patients with AIT.

METHODS

We retrospectively studied 2016 consecutive women and 258 men with AIT seen at our referral center in the period from 2004 to 2008. All patients were screened for the presence of PCA in the serum.

RESULTS

The prevalence of serum PCA in female patients was 29.7% and progressively increased from 13% in the first-second decade of life to peak at 42% in the ninth decade. During follow up, 21.1% of the PCA-positive patients converted to PCA-negative status. Mean (±standard deviation) basal PCA levels in this group were significantly lower (32 ± 28 U/mL) compared with those remaining PCA positive (129 ± 200 U/mL). A similar prevalence (29.8%) with a similar age-dependency was found in male patients.

CONCLUSIONS

In conclusion, our study demonstrates a high, age-dependent prevalence of PCA in an unselected large population of patients with AIT.

[Prevalence and predictive factors of parietal cell antibody positivity in autoimmune thyroid disease]

BACKGROUND AND OBJECTIVES

Our aim was to evaluate the prevalence of parietal cell antibodies (PCA) in patients with autoimmune thyroid disease (ATD).

MATERIAL AND METHODS

We performed a descriptive, cross-sectional study of patients with ATD. The presence of PCA was determined. Elevated antithyroid antibodies (ATAs) were defined as those higher than the 75th percentile of distribution. Multivariate logistic regression models were built to assess the independent contribution of the following variables to PCA positivity: age, sex, hemoglobin, medium corpuscular volume (MCV), dose/Kg of levothyroxine (LT4), disease duration and elevated ATA levels.

RESULTS

A total of 148 patients were included (137 females). The mean age was 45.7 (SD 15) years and disease duration was 4.5 (SD 4) years. Forty-three patients (29%) with Graves' disease and 105 (71%) with primary hypothyroidism were included. The 75th percentile of distribution was 420U/ml for anti-peroxidase antibodies and 200U/ml for anti-thyroglobulin antibodies. PCA positivity was found in 30 patients, with an overall prevalence of 20.3%. PCA positivity with titers higher than 1/640 was found in 19 patients (12.8%). The only independent predictive factor of PCA positivity was the presence of elevated levels of ATAs (odds ratio (OR)=3; 95% confidence interval (CI): 1.1-8.6; p=0.04). The only independent predictive factor of PCA positivity at titers >/=1/640 was also the presence of elevated levels of ATAS (OR=7.3; 95% CI: 1.6-32.7; p=0.009).

CONCLUSIONS

The prevalence of PCA positivity in patients with ATD was 20%. Elevated levels of ATAs increase the risk of PCA positivity.

Circulating acylated ghrelin level decreases in accordance with the extent of atrophic gastritis

PURPOSE

We attempted to clarify the significance of atrophic change of gastric mucosa for reduction of plasma ghrelin concentration irrespective of Helicobacter pylori (Hp) infection.

METHODS

Plasma acylated (acyl-)ghrelin concentration in 220 subjects, both with and without atrophic gastritis, was measured with an enzyme immunoassay kit. The extent of atrophic change of gastric mucosa was assessed and graded endoscopically. Hp infection was determined by assay of the anti-Hp antibody with an ELISA assay kit.

RESULTS

Plasma acyl-ghrelin concentration was significantly lower in the Hp positive than the Hp negative group, and Hp eradication significantly increased plasma acyl-ghrelin concentrations in Hp positive subjects. Plasma acyl-ghrelin was significantly lower in subjects with severely atrophic gastritis than in those with mild or moderate atrophic gastritis, irrespective of Hp infection or age group (<60 years old or > or = 60 years old). In male subjects with a normal body mass index, plasma acyl-ghrelin concentrations in subjects with severely atrophic gastritis were significantly lower than those in subjects with mildly or moderately atrophic gastritis, suggesting that the results of the study are independent of emaciation or obesity. Logistic regression analysis showed that gastric atrophy is the key factor that modulates plasma acyl-ghrelin levels.

CONCLUSIONS

The results suggest that plasma acyl-ghrelin concentration decreases in accordance with the extent of atrophic change in gastric mucosa irrespective of Hp infection, indicating that the low plasma acyl-ghrelin level of subjects with Hp infection is mainly caused by the progress of atrophic changes in gastric mucosa.

Gastric ghrelin in relation to gender, stomach topography and Helicobacter pylori in dyspeptic patients

AIM: To investigate the level of gastric ghrelin in stomach mucosa of dyspeptic patients in relation to Helicobacter pylori (H pylori) infection, bacterial cytotoxicity, topography and gender.

METHODS: The study comprised 40 premenopausal women (19 H pylori positive) and 48 men (17 H pylori positive) with functional dyspepsia. All gastric biopsy specimens revealed normal mucosa or non-atrophic gastritis. Gastric ghrelin concentration was determined by Enzyme linked immunosorbent assay. The cagA and vacA strains of bacterial DNA were identified by multiplex polymerase chain reaction.

RESULTS: In general, infection with H pylori caused an increase in gastric ghrelin level regardless of gender and stomach topography. Significantly more hormone was present in both, non-infected and H pylori positive female samples, as compared to males. The distribution of bacterial strains showed cagA(+) vacA s1m1 and cagA(-) vacA s2m2 genotypes as the most common infections in the studied population. A tendency to higher ghrelin levels was observed in less cytotoxic (cagA negative) strain-containing specimens from the antrum and corpus of both gender groups (without statistical significance).

CONCLUSION: An increase in gastric ghrelin levels at the stage of non-atrophic gastritis in H pylori positive patients, especially in those infected with cagA(-) strains, can exert a gastroprotective effect.

Ghrelin and Helicobacter pylori infection

Ghrelin is primarily secreted from the stomach and has been implicated in the coordination of eating behavior and weight regulation. Ghrelin also plays an essential role in the mechanism of gastric mucosal defense. Thus, it is important to clarify which diseases primarily influence changes in plasma ghrelin concentrations. Helicobacter pylori (H pylori) infection is involved in the pathogenesis of gastritis, gastric and duodenal ulcer, gastric carcinoma, and mucosa-associated lymphoid tissue lymphoma. H pylori eradication is related to body weight change. Compared, H pylori infected and negative subjects with normal body mass index, plasma ghrelin concentration, gastric ghrelin mRNA, and the number of ghrelin producing cells in gastric mucosa are significantly lower in H pylori infected subjects than in H pylori-negative controls. Plasma ghrelin concentration decreases with the progression of gastric atrophy. Impaired gastric ghrelin production in association with atrophic gastritis induced by H pylori infection accounts for the decrease in plasma ghrelin concentration. However, the ratio of plasma acylated ghrelin to total ghrelin levels is higher in patients with chronic atrophic gastritis than in healthy subjects. This may result from the compensatory increase in plasma active ghrelin concentration in response to gastric atrophy. After H pylori eradication, gastric preproghrelin mRNA expression is increased nearly 4-fold in most cases. However, changes in plasma ghrelin concentrations before and after H pylori cure are not associated with the gastric ghrelin production. Plasma ghrelin changes are inversely correlated with both body weight change and initial plasma ghrelin levels.

Gastric secretion

PURPOSE OF REVIEW

This review summarizes the past year's literature regarding the regulation and assessment of gastric acid secretion.

RECENT FINDINGS

Gastric acid secretion is regulated by biologic agents produced and released by enteroendocrine cells and neurons as well as by exogenously administered substances and infection. Too much acid can lead to gastroesophageal reflux disease, peptic ulcer disease, and stress-related erosion/ulcer disease. Too little acid can interfere with the absorption of certain nutrients, predispose to enteric infection, and interfere with the absorption of some medications. Gastrin, histamine, gastrin-releasing peptide, ghrelin, orexin, and glucocorticoids stimulate whereas leptin, glucagon-like peptide 1, and Helicobacter pylori inhibit acid secretion. Helicobacter pylori inhibits the transcriptional activity of HK-ATPase, the proton pump of the parietal cell.

SUMMARY

A better understanding of the pathways and mechanisms regulating gastric acid secretion should lead to improved management of patients with acid-induced disorders as well as those who secrete too little acid.

Serum pepsinogen levels and their influencing factors: a population-based study in 6990 Chinese from North China

AIM

To explore the essential characteristics of serum pepsinogen (PG) levels in Chinese people, by analyzing the population-based data on the serum levels of PG I and II and the PG I/II ratio, and their influencing factors in Chinese from North China.

METHODS

A total of 6990 subjects, who underwent a gastric cancer screening in North China from 1997 to 2002, were collected in this study. Serum pepsinogen levels were measured by enzyme-linked immunosorbent assay (ELISA). H pylori status was determined by histological examination and H pylori-IgG ELISA. The cut-off point was calculated by using receiving operator characteristics (ROC) curves. Factors linked to serum PG I/II ratio were identified using a multivariate logistic regression.

RESULTS

The serum PG I and PG II levels were significantly higher in males than in females (95.2 microg/L vs 79.7 microg/L, P < 0.01; 12.1 microg/L vs 9.4 microg/L, P < 0.01), PG I/II ratio was significantly lower in males than in females (7.9 vs 8.3, P < 0.01). The PG I/II ratio decreased significantly in the aged groups following the progression of gastric mucosa from normal to non-atrophic and atrophic lesions (10.4, 8.8, and 6.6, respectively). The serum PG I and II levels were significantly higher in patients with H pylori infection than in those without H pylori infection (88.7 microg/L vs 81.4 microg/L, P < 0.01; 11.4 microg/L vs 8.4 microg/L, P < 0.01), while the PG I/II ratio was significantly lower in patients with H pylori infection than in those without H pylori infection (7.7 vs 9.6, P < 0.01). For patients with atrophic lesions, the area under the PG I/II ROC curve was 0.622. The best cut-off point for PG I/II was 6.9, with a sensitivity of 53.2%, and a specificity of 67.5%. Factors linked to PG I/II were sensitive to identified PG using a multinomial logistic regression relying on the following inputs: males (OR: 1.151, 95% CI: 1.042-1.272, P = 0.006), age > or = 61 years (OR: 1.358, 95% CI: 1.188-1.553, P = 0.000), atrophic lesion (OR: 2.075, 95% CI: 1.870-2.302, P = 0.000), and H pylori infection (OR: 1.546, 95% CI: 1.368-1.748, P = 0.000).

CONCLUSION

The essential characteristics of serum PG levels in Chinese are significantly skewed from the normal distribution, and influenced by age, sex, gastric mucosa lesions and H pylori infection. PG I/II ratio is more suitable for identifying subgroups with different influence factors compared with PG I or PG II alone.

Serum pepsinogen levels and their influencing factors: a population-based study in 6990 Chinese from North China

AIM

To explore the essential characteristics of serum pepsinogen (PG) levels in Chinese people, by analyzing the population-based data on the serum levels of PG I and II and the PG I/II ratio, and their influencing factors in Chinese from North China.

METHODS

A total of 6990 subjects, who underwent a gastric cancer screening in North China from 1997 to 2002, were collected in this study. Serum pepsinogen levels were measured by enzyme-linked immunosorbent assay (ELISA). H pylori status was determined by histological examination and H pylori-IgG ELISA. The cut-off point was calculated by using receiving operator characteristics (ROC) curves. Factors linked to serum PG I/II ratio were identified using a multivariate logistic regression.

RESULTS

The serum PG I and PG II levels were significantly higher in males than in females (95.2 microg/L vs 79.7 microg/L, P < 0.01; 12.1 microg/L vs 9.4 microg/L, P < 0.01), PG I/II ratio was significantly lower in males than in females (7.9 vs 8.3, P < 0.01). The PG I/II ratio decreased significantly in the aged groups following the progression of gastric mucosa from normal to non-atrophic and atrophic lesions (10.4, 8.8, and 6.6, respectively). The serum PG I and II levels were significantly higher in patients with H pylori infection than in those without H pylori infection (88.7 microg/L vs 81.4 microg/L, P < 0.01; 11.4 microg/L vs 8.4 microg/L, P < 0.01), while the PG I/II ratio was significantly lower in patients with H pylori infection than in those without H pylori infection (7.7 vs 9.6, P < 0.01). For patients with atrophic lesions, the area under the PG I/II ROC curve was 0.622. The best cut-off point for PG I/II was 6.9, with a sensitivity of 53.2%, and a specificity of 67.5%. Factors linked to PG I/II were sensitive to identified PG using a multinomial logistic regression relying on the following inputs: males (OR: 1.151, 95% CI: 1.042-1.272, P = 0.006), age > or = 61 years (OR: 1.358, 95% CI: 1.188-1.553, P = 0.000), atrophic lesion (OR: 2.075, 95% CI: 1.870-2.302, P = 0.000), and H pylori infection (OR: 1.546, 95% CI: 1.368-1.748, P = 0.000).

CONCLUSION

The essential characteristics of serum PG levels in Chinese are significantly skewed from the normal distribution, and influenced by age, sex, gastric mucosa lesions and H pylori infection. PG I/II ratio is more suitable for identifying subgroups with different influence factors compared with PG I or PG II alone.