Serum gastrin and chromogranin A during medium- and long-term acid suppressive therapy: a case-control study

Factors influencing blood tumor marker concentrations in the absence of neoplasia

BACKGROUND

Tumor markers (TMs) are a heterogeneous group of molecules used in the diagnosis, prognosis and follow-up of cancer patients. During neoplastic differentiation, cells can either directly synthesize or induce the synthesis of TMs, and the release of these molecules into the bloodstream allows their quantification in biological fluids. Although very small concentrations of TMs are usually present in the serum or plasma of healthy subjects, increased concentrations may also be found in the presence of benign diseases or due to technical interference, producing false positive results.

MATERIAL AND METHODS AND RESULTS

Our review analyses the causes of false positives described between January 1970 to February 2023 for the TMs most frequently used in clinical practice: α-fetoprotein (AFP), β2-microglobulin (β2-M), cancer antigen 15-3 (CA 15-3), cancer antigen CA 19-9 (CA 19-9), cancer antigen CA 72-4 (CA 72-4), cancer antigen 125 (CA 125), carcinoembryonic antigen (CEA), chromogranin A (CgA), choriogonadotropin (hCG), cytokeratin 19 fragment (CYFRA 21-1), neuron-specific enolase (NSE), human epididymis protein 4 (HE4), serum HER2 (sHER2), squamous cell carcinoma antigen (SCCA), protein induced by vitamin K absence-II (PIVKA-II), Pro-gastrin-releasing peptide (Pro-GRP), prostate-specific antigen (PSA), Protein S-100 (S-100) and thyroglobulin (Tg). A total of 247 references were included.

CONCLUSIONS

A better understanding of pathophysiological processes and other conditions that affect the concentration of TMs might improve the interpretation of results and their clinical application.

The Impact of Sex on the Response to Proton Pump Inhibitor Treatment

Proton pump inhibitor (PPI) treatment is responsible for substantial gastrin elevation secondary to reduced intragastric acidity. Due to the increasing global prevalence of PPI users, concerns have been raised about the clinical significance of continuous gastrin elevation and its potential long-term side effects. Hypergastrinemia secondary to PPIs has trophic effects on gastric mucosa, leading to enterochromaffin-like cell hyperplasia and gastric (fundic) polyp formation, and it is believed to provoke acid rebound following PPI withdrawal that induces PPI overutilization. Previous studies have found higher gastrin release following PPI therapy in females compared with males, and sex differences have also been demonstrated in pharmacokinetic parameters and dose requirements for acid reflux. It is conceivable that females might be at increased risk of PPI overuse, because they often receive higher milligram-per-kilogram doses. The prevalence of PPI use is more common among females, and the female sex is a risk factor for adverse drug reactions. This non-systematic review outlines the current knowledge of the impact of biological sex on the response to PPIs. The aim is to highlight the female sex as a potential risk factor that could be a step toward precision medicine and should be considered in future research on the response to PPI treatment.

Biochemical Assessment of Pheochromocytoma and Paraganglioma

Pheochromocytoma and paraganglioma (PPGL) require prompt consideration and efficient diagnosis and treatment to minimize associated morbidity and mortality. Once considered, appropriate biochemical testing is key to diagnosis. Advances in understanding catecholamine metabolism have clarified why measurements of the O-methylated catecholamine metabolites rather than the catecholamines themselves are important for effective diagnosis. These metabolites, normetanephrine and metanephrine, produced respectively from norepinephrine and epinephrine, can be measured in plasma or urine, with choice according to available methods or presentation of patients. For patients with signs and symptoms of catecholamine excess, either test will invariably establish the diagnosis, whereas the plasma test provides higher sensitivity than urinary metanephrines for patients screened due to an incidentaloma or genetic predisposition, particularly for small tumors or in patients with an asymptomatic presentation. Additional measurements of plasma methoxytyramine can be important for some tumors, such as paragangliomas, and for surveillance of patients at risk of metastatic disease. Avoidance of false-positive test results is best achieved by plasma measurements with appropriate reference intervals and preanalytical precautions, including sampling blood in the fully supine position. Follow-up of positive results, including optimization of preanalytics for repeat tests or whether to proceed directly to anatomic imaging or confirmatory clonidine tests, depends on the test results, which can also suggest likely size, adrenal vs extra-adrenal location, underlying biology, or even metastatic involvement of a suspected tumor. Modern biochemical testing now makes diagnosis of PPGL relatively simple. Integration of artificial intelligence into the process should make it possible to fine-tune these advances.

AGA Clinical Practice Update on De-Prescribing of Proton Pump Inhibitors: Expert Review

DESCRIPTION

Proton pump inhibitors (PPIs) are among the most commonly used medications in the world. Developed for the treatment and prevention of acid-mediated upper gastrointestinal conditions, these agents are being used increasingly for indications where their benefits are less certain. PPI overprescription imposes an economic cost and contributes to polypharmacy. In addition, PPI use has been increasingly linked to a number of adverse events (PPI-associated adverse events [PAAEs]). Therefore, de-prescribing of PPIs is an important strategy to lower pill burden while reducing real costs and theoretical risks. The purpose of this clinical update was to provide Best Practice Advice (BPA) statements about how to approach PPI de-prescribing in ambulatory patients.

METHODS

Our guiding principle was that, although PPIs are generally safe, patients should not use any medication when there is not a reasonable expectation of benefit based on scientific evidence or prior treatment response. Prescribers are responsible for determining whether PPI use is absolutely or conditionally indicated and, when uncertainty exists, to incorporate patient perspectives into PPI decision making. We collaboratively outlined a high-level "process map" of the conceptual approach to de-prescribing PPIs in a clinical setting. We identified the following 3 key domains that required BPA guidance: documentation of PPI indication; identifying suitable candidates for consideration of de-prescribing; and optimizing successful de-prescribing. Co-authors drafted 1 or more potential BPAs, supported by literature review, for each domain. All co-authors reviewed, edited, and selected or rejected draft BPAs for inclusion in the final list submitted to the American Gastroenterological Association Governing Board. Because this was not a systematic review, we did not carry out a formal rating of the quality of evidence or strength of the presented considerations. Best Practice Advice Statements BEST PRACTICE ADVICE 1: All patients taking a PPI should have a regular review of the ongoing indications for use and documentation of that indication. This review should be the responsibility of the patient's primary care provider. BEST PRACTICE ADVICE 2: All patients without a definitive indication for chronic PPI should be considered for trial of de-prescribing. BEST PRACTICE ADVICE 3: Most patients with an indication for chronic PPI use who take twice-daily dosing should be considered for step down to once-daily PPI. BEST PRACTICE ADVICE 4: Patients with complicated gastroesophageal reflux disease, such as those with a history of severe erosive esophagitis, esophageal ulcer, or peptic stricture, should generally not be considered for PPI discontinuation. BEST PRACTICE ADVICE 5: Patients with known Barrett's esophagus, eosinophilic esophagitis, or idiopathic pulmonary fibrosis should generally not be considered for a trial of de-prescribing. BEST PRACTICE ADVICE 6: PPI users should be assessed for upper gastrointestinal bleeding risk using an evidence-based strategy before de-prescribing. BEST PRACTICE ADVICE 7: Patients at high risk for upper gastrointestinal bleeding should not be considered for PPI de-prescribing. BEST PRACTICE ADVICE 8: Patients who discontinue long-term PPI therapy should be advised that they may develop transient upper gastrointestinal symptoms due to rebound acid hypersecretion. BEST PRACTICE ADVICE 9: When de-prescribing PPIs, either dose tapering or abrupt discontinuation can be considered. BEST PRACTICE ADVICE 10: The decision to discontinue PPIs should be based solely on the lack of an indication for PPI use, and not because of concern for PAAEs. The presence of a PAAE or a history of a PAAE in a current PPI user is not an independent indication for PPI withdrawal. Similarly, the presence of underlying risk factors for the development of an adverse event associated with PPI use should also not be an independent indication for PPI withdrawal.

Vasostatin-1 as a potential novel circulating biomarker in patients with chronic systolic heart failure: A pilot study

BACKGROUND AND AIMS

Previous studies have shown that circulating chromogranin A (CgA) increases in patients with chronic systolic heart failure (HF). Aim of the present study is to evaluate the potential role of circulating vasostatin-1 (VS-1), a cardioregulatory fragment of CgA, as prognostic marker in patients with chronic HF.

MATERIALS AND METHODS

The plasma levels of CgA and VS-1 were determined in 80 patients with chronic systolic HF. Patients were followed-up to evaluate the occurrence of cardiovascular (CV) events.

RESULTS

CgA and VS-1 plasma levels were significantly higher in patients with CV events at follow-up. VS-1, but not CgA, was associated to NT-proBNP. No significant association of CgA and VS-1 with left ventricular ejection fraction (LVEF) was observed. CgA, NT-proBNP and age, but not VS-1, were independent predictors of CV events.

CONCLUSION

In patients with chronic systolic HF those who experienced CV events had higher levels of VS-1 and CgA. Given its established effect on cardiac cells, the association of VS-1 levels with NT-proBNP levels but not with LVEF, suggests that this fragment might provide complementary information to NT-proBNP and CgA in HF patients.

Gastrin and the Moderate Hypergastrinemias

The antral hormone gastrin potently regulates gastric acid secretion and fundic mucosal growth. Consequently, appropriate gastrin secretion and plasma concentrations are important for the early phases of digestion. This review describes as the first premise the normal biogenesis of gastrin in the antral mucosa, but also mentions the extraantral expression. Subsequently, the molecular nature and concentration levels of gastrin in serum or plasma are overviewed. Third, assays for accurate measurements of plasma or serum concentrations are commented. Finally, the problem of moderate hypergastrinemia due to Helicobacter pylori infections and/or treatment with proton-pump inhibitors (PPI) is discussed. The review concludes that accurate measurement of the true concentrations of bioactive gastrins in plasma is important. Moreover, it suggests that moderate hypergastrinemias are also essential health issues that require serious attention.

Risk factors for progression of appendiceal neuroendocrine tumours: low-stage tumours <5 mm appear to be overwhelmingly indolent and may merit a separate designation

AIMS

Appendiceal well-differentiated neuroendocrine tumours (NETs) are usually incidental and clinically benign. Several studies have reported different risk factors for nodal metastasis. The aim of this study was to investigate our appendiceal NETs (App-NETs) to determine the factors associated with malignant behaviour.

METHODS AND RESULTS

For 120 App-NETs, we reviewed the clinical presentation and follow-up, including serum chromogranin A (CgA) levels, and compiled several microscopic variables. Pathological factors were compared with nodal status and time to biochemical recurrence (elevated serum CgA level) by the use of Cox regression. We also reviewed similar App-NET data in the Surveillance, Epidemiology, and End Results (SEER) Programme. Among our 120 cases, seven patients had positive lymph nodes, and nine developed subsequent elevation of CgA levels; none developed distant metastases or died of disease. Only three patients had grade 2 NETs; none had nodal disease, and one developed an elevated CgA level. Increasing tumour size was associated with an increased risk of nodal disease [odds ratio (OR) 4.99, P = 0.0055). All seven node-positive cases were ≥13 mm. Factors associated with elevated CgA levels included age (OR 1.04, P = 0.041), pT4 disease (OR 10.22, P = 0.033), and nodal disease (OR 24.0, P = 0.012), but not size (OR 2.13, P = 0.072). Of the 1492 reported App-NETs in the SEER database with data on tumour size, 137 (9%) were pN1; only five of these (4%) were coded as being <5 mm.

CONCLUSIONS

Small (<5 mm) App-NETs that do not invade the serosa or mesoappendix appear to be overwhelmingly benign and low-grade, requiring neither Ki67 staining nor synoptic reporting. Given their indolent behaviour, different nomenclature or staging may be more appropriate for these NETs.

Pharmacokinetics of single and repeated oral doses of esomeprazole and gastrin elevation in healthy males and females

OBJECTIVE

Gastrin elevation secondary to proton pump inhibitor (PPI) therapy is well documented. Recent studies have demonstrated a sex-related difference where females on PPIs have significantly higher baseline gastrin levels than males. The aim of the study was to analyse the pharmacokinetics of esomeprazole and short-term effect on serum gastrin levels and evaluate potential sex-related difference.

MATERIALS AND METHODS

Healthy volunteers received 40 mg of esomeprazole daily for five days. After the 1st and 5th dose blood samples for fasting gastrin and pharmacokinetic analysis were collected at scheduled time-points for eight hours. Esomeprazole was analysed by liquid chromatography and gastrin concentrations were measured using radioimmunoassay.

RESULTS

A total of 30 volunteers were enrolled. Females had higher median baseline gastrin (pM) than males 12 (IQR 10-15) vs. 7 (IQR 4-11) (p = .03). In the study cohort, median gastrin levels rose from 10 (IQR 6-14) to 15 (IQR 13-20) (p = .0002). The serum levels for esomeprazole increased by an average of 299.8 ng/mL (p < .001) from day 1 to day 5. Comparison of the esomeprazole pharmacokinetic parameters between males and females revealed no significant sex-related differences. No significant correlation was found between the AUC and the gastrin level on day 5 (p = .15).

CONCLUSIONS

In healthy volunteers, serum gastrin increased significantly after a four-day PPI-therapy. There was also a significant increase in serum esomeprazole from day 1 to day 5. The increase in gastrin and esomeprazole concentration was not related to sex and no significant sex-related difference was found in terms of pharmacokinetic parameters. European Clinical Trial Database (2015-002230-41).

Chromogranin Serves as Novel Biomarker of Endocrine and Gastric Autoimmunity

CONTEXT

The glycoprotein chromogranin A (CgA) is expressed by endocrine and neuroendocrine cells. High levels of serum CgA serve as markers of neuroendocrine tumors (NET), but its role in autoimmunity has not been assessed.

OBJECTIVE

To investigate CgA utility as a marker of endocrine autoimmunity.

METHODS

CgA serum levels were evaluated in 807 consecutive unselected participants (cross-sectional study) with the time-resolved amplified cryptate emission technology.

RESULTS

Serum CgA concentrations were increased in 66%, 39%, 38%, and 24% of patients with NET, type 1 diabetes (T1D), autoimmune gastritis (AG) and autoimmune polyendocrinopathy (AP), respectively. Compared with healthy participant controls (C), the odds of positive CgA measurement were up to 28 times higher in the disease groups. In detail, the odds ratios (ORs) for positive CgA levels were 27.98, 15.22, 7.32 (all P < 0.0001) and 3.89 (P = 0.0073) in patients with NET, T1D, AG, and AP, respectively. In AG, CgA and serum gastrin correlated positively (r = 0.55; P < 0.0001). The area under the receiver operating characteristic curve to predict AG was higher for parietal cell antibody (PCA) positivity than for CgA (0.84 vs 0.67; P < 0.0001). However, in combination with PCA and intrinsic factor autoantibodies, CgA independently improved prediction of AG (OR 6.5; P = 0.031). An impact of age on CgA positivity and on CgA value was detected (P < 0.0001) while current smoking significantly increased CgA serum levels by 25% (P = 0.0080).

CONCLUSION

CgA qualifies as a novel biomarker for T1D, AP, and AG.

Predictors of Gastrin Elevation Following Proton Pump Inhibitor Therapy

GOALS

The goal of this study was to elucidate the most important predictors for elevation of gastrin in patients on long-term PPI therapy through analysis of data from 2 published studies in Icelandic patients with erosive GERD.

BACKGROUND

Gastrin elevation is a known but variable consequence of proton pump inhibitor (PPI) therapy. Concerns have been raised about the clinical importance of chronic PPI induced gastrin elevation.

STUDY

This cross-sectional analysis included patients with endoscopically verified erosive esophagitis receiving long-term PPI therapy. PPI exposure in dosage over weight (mg/kg) and dosage over body surface area (mg/m) was compared with fasting gastrin levels in two separate multiple linear regression models. Data was collected on age, gender, weight, H. pylori infection, smoking, PPI duration and type.

RESULTS

Overall data from 157 patients (78 females) were analyzed. Median serum gastrin levels were higher in females than males (92 vs. 60 pg/mL; P=0.001). Simple linear regression showed a correlation between serum gastrin levels and gender (P=0.0008) as well as PPI exposure in mg/kg (P=0.0001) and mg/m (P=0.0001). Multiple linear regression analysis showed that PPI exposure, both in mg/kg (β=0.95 [CI=0.4-1.5]; P=0.001) and mg/m (β=0.02 [CI=0.0-0.0]; P=0.0015) along with female gender (β=0.2 [CI=0.0-0.4]; P=0.02) predicted higher gastrin values.

CONCLUSIONS

Dosage and female gender seem to play an important role in the development of gastrin elevation on PPI therapy. A significant correlation was found between fasting serum gastrin and dosage of PPIs over weight and body surface area.

Snapshot of proton pump inhibitors prescriptions in a tertiary care hospital in Switzerland: less is more?

Background Proton pump inhibitors are among the most widely prescribed drugs in the world, but more than half of the indications for prescription are unjustified. The misuse of this therapeutic class has heavy consequences such as additional health costs, adverse drug reactions following long-term use and gastric acid rebound when the proton pump inhibitor is discontinued. Objective The overprescription of proton pump inhibitors is therefore becoming a public health problem, which led us to evaluate their use within the Geneva University Hospitals. Setting Patients hospitalized in two divisions of the department of internal medicine of the Geneva University Hospitals on a single day. Methods This is a register-based cross-sectional study and it collected data about the prescription pattern of proton pump inhibitors by consulting the electronic records of patients included. Main outcome measure To determine if the proton pump inhibitors prescription is made according to the market authorization and the available guidelines. Results Hundred-eighty patients were included. 54% of patients were on proton pump inhibitors, 29% of whom had their treatment initiated at hospital. Of the indications for treatment, 72% were not justified and 63% of the justified indications did not have an adequate dosage. Therefore, in all patients with a proton pump inhibitor at hospital, only 11% had a justified indication with an adequate dose. Finally, 87% of known home prescriptions were renewed on admission and among them, 71% did not have a justified or possibly justified indication according to the guidelines. Conclusion Indication for treatment inside the hospital was not justified in 72% of patients and only 11% had a justified indication with an adequate dosage. Precise guidelines with evidence-based indications and adequate daily doses would help to correctly prescribe proton pump inhibitors. Moreover, patients should benefit from a thorough evaluation of their treatment.

Prognostic role of chromogranin A in castration-resistant prostate cancer: A meta-analysis

We aimed to investigate the prognostic value of chromogranin A (CgA) in castration-resistant prostate cancer (CRPC). We conducted a systematic literature search of PubMed, Web of Science, and EMBASE for citations published prior to September 2017 that described CgA and CRPC and performed a standard meta-analysis on survival outcomes. Our meta-analysis included eight eligible studies with 686 patients. The results were as follows: progression-free survival (PFS) was associated with CgA level (hazard ratio [HR] = 2.47, 95% confidence interval [CI]: 1.47-4.14, P = 0.0006); PFS was relative to CgA change (HR = 9.22, 95% CI: 3.03-28.05, P < 0.0001); and overall survival (OS) was relative to CgA level (HR = 1.47, 95% CI: 1.15-1.87, P = 0.002). When we divided the patients into two groups according to therapy status, the result for OS relative to CgA level was an HR of 1.26 (95% CI: 1.09-1.45, P = 0.001) in the first-line hormonal therapy group, and an HR of 2.33 (95% CI: 1.40-3.89, P = 0.001) in the second-line hormonal therapy or chemotherapy group. This meta-analysis indicated that a high CgA level had a negative influence on OS and PFS in CRPC patients. In addition, CRPC patients with a rising CgA had a shorter PFS. Further studies are needed to verify the prognostic value of CgA in CRPC.

Chromogranin A and its fragments in cardiovascular, immunometabolic, and cancer regulation

Chromogranin A (CgA)-the index member of the chromogranin/secretogranin secretory protein family-is ubiquitously distributed in endocrine, neuroendocrine, and immune cells. Elevated levels of CgA-related polypeptides, consisting of full-length molecules and fragments, are detected in the blood of patients suffering from neuroendocrine tumors, heart failure, renal failure, hypertension, rheumatoid arthritis, and inflammatory bowel disease. Full-length CgA and various CgA-derived peptides, including vasostatin-1, pancreastatin, catestatin, and serpinin, are expressed at different relative levels in normal and pathological conditions and exert diverse, and sometime opposite, biological functions. For example, CgA is overexpressed in genetic hypertension, whereas catestatin is diminished. In rodents, the administration of catestatin decreases hypertension, cardiac contractility, obesity, atherosclerosis, and inflammation, and it improves insulin sensitivity. By contrast, pancreastatin is elevated in diabetic patients, and the administration of this peptide to obese mice decreases insulin sensitivity and increases inflammation. CgA and the N-terminal fragment of vasostatin-1 can enhance the endothelial barrier function, exert antiangiogenic effects, and inhibit tumor growth in animal models, whereas CgA fragments lacking the CgA C-terminal region promote angiogenesis and tumor growth. Overall, the CgA system, consisting of full-length CgA and its fragments, is emerging as an important and complex player in cardiovascular, immunometabolic, and cancer regulation.

Proton Pump Inhibitors and Fracture Risk: A Review of Current Evidence and Mechanisms Involved

The number of patients with gastroesophageal problems taking proton pump inhibitors (PPIs) is increasing. Several studies suggested a possible association between PPIs and fracture risk, especially hip fractures, but the relationship remains contentious. This review aimed to investigate the longitudinal studies published in the last five years on the relationship between PPIs and fracture risk. The mechanism underlying this relationship was also explored. Overall, PPIs were positively associated with elevated fracture risk in multiple studies (n = 14), although some studies reported no significant relationship (n = 4). Increased gastrin production and hypochlorhydria are the two main mechanisms that affect bone remodeling, mineral absorption, and muscle strength, contributing to increased fracture risk among PPI users. As a conclusion, there is a potential relationship between PPIs and fracture risks. Therefore, patients on long-term PPI treatment should pay attention to bone health status and consider prophylaxis to decrease fracture risk.

Limited role of Chromogranin A as clinical biomarker for pancreatic neuroendocrine tumors

BACKGROUND

Serum Chromogranin A (CgA) is widely used as a biomarker for pancreatic neuroendocrine tumors (PanNETs). The aim of this study was to investigate the value of CgA as a diagnostic and prognostic marker for well-differentiated PanNETs.

METHODS

Patients with well-differentiated PanNET and a baseline CgA measurement, between 2011 and 2016 were reviewed. The diagnostic value was determined by comparing CgA values from patients with PanNETs to those with other pancreatic neoplasms and healthy controls. The Kaplan-Meier method was used to investigate the CgA prognostic significance.

RESULTS

Ninety-nine patients met inclusion criteria. As a diagnostic marker, CgA had a sensitivity of 66%, specificity of 95%, and overall accuracy of 71%. The use of PPIs was associated with a higher CgA level (p = 0.015). When excluding patients on PPIs, CgA accuracy in distinguishing PanNETs from other pancreatic neoplasms was 66%, the sensitivity and specificity were 60% and 75% respectively. Elevated CgA (p = 0.004), Ki67% (p < 0.001), tumor grade (p < 0.001) and stage of disease (p = 0.036) were associated with disease-specific survival.

CONCLUSION

CgA has a limited role as a diagnostic biomarker for well-differentiated PanNETs. An elevated CgA level may have prognostic value but its role should be further investigated with respect to other known pathological factors.

The effect of hypergastrinemia following sleeve gastrectomy and pantoprazole on type 2 diabetes mellitus and beta-cell mass in Goto-Kakizaki rats

PURPOSE

Metabolic surgery alters the secretion of gastrointestinal hormones that influence glycemic control. Elevated gastrin has been suggested to benefit patients with type 2 diabetes and has been reported following sleeve gastrectomy in rats. The present study compares the effect of hypergastrinemia following sleeve gastrectomy with proton-pump inhibitor therapy on glycemic control and beta-cell mass in lean, diabetic animals.

METHODS

Thirty-three diabetic Goto-Kakizaki rats were randomized into pantoprazole + sham operation (GK-PPI), sleeve gastrectomy (GK-SG) and vehicle + sham operation (GK-V). Body weight, glucose parameters, HbA1c, glucagon-like peptide 1, gastrin, insulin and lipids were evaluated for eighteen postoperative weeks. Total beta-cell mass was quantified by optical projection tomography.

RESULTS

After surgery, body weight development was equal among groups (P _g = 0.75). Fasting and stimulated gastrin increased for GK-PPI and GK-SG vs. GK-V (p < 0.05 for all). Fasting blood glucose was decreased for GK-PPI and GK-SG vs. GK-V (p < 0.05 and p = 0.052). HbA1c was lower for GK-SG vs. GK-V at 6 weeks and for GK-PPI vs. GK-V at twelve- and eighteen weeks postoperative (p < 0.05 for all); a borderline difference was observed for GK-SG vs. GK-V at 18 weeks (p = 0.054). Total- and LDL cholesterol was elevated for GK-PPI compared to the other two groups (p < 0.05 for all). Beta-cell mass did not differ among groups (p = 0.35).

CONCLUSIONS

Hypergastrinemia following sleeve gastrectomy and pantoprazole has a similar, modest effect on glycemic control in Goto-Kakizaki rats but does not enhance beta-cell mass after 18 weeks. Hypergastrinemia in the setting of T2DM might be of clinical relevance.

Proton pump inhibitors (PPIs) may cause gastric cancer - clinical consequences

Recently, two epidemiological studies showed that long-term treatment with proton pump inhibitors (PPIs) increased the risk of gastric cancer. It is well known that hypergastrinemia predisposes to gastric neoplasia in animals as well as man. Recently a study showed that hypergastrinemic patients had an increased risk of gastric cancer when followed for about 25 years. It is likely that hypergastrinemia is the pathogenic factor for gastric carcinogenesis due to PPI. PPI are the only group of drugs that causes long-term hypergastrinemia in the doses used in a clinical setting. Due to the likely carcinogenic effect, PPIs should be used carefully. Moreover, since the carcinogenic effect of Helicobacter pylori (Hp) infection also may be mediated by an increase in gastrin, Hp should be eradicated whenever treatment with PPI is initiated. In peptic ulcer disease Hp eradication is the treatment of choice. Gastro-oesophageal reflux disease (GERD) is the most prevalent condition leading to long-term use of inhibitors of gastric acid secretion. Only in severe oesophagitis should the treatment be initiated by PPIs, whereas histamine-2 (H-2) blockers ought to be the initial option in most cases of GERD particularly since PPI treatment induces tolerance to H-2 blockers. In the cases where long-term PPI treatment is necessary, the dose should be adjusted by the determination of chromogranin A, which in a way reflects 24-h gastrin exposure. Finally, due to latency of neoplasia, the use of PPI must be very restricted in children and young adults.

Regulation of tumor growth by circulating full-length chromogranin A

Chromogranin A (CgA), a neuroendocrine secretory protein, and its fragments are present in variable amounts in the blood of normal subjects and cancer patients. We investigated whether circulating CgA has a regulatory function in tumor biology and progression. Systemic administration of full-length CgA, but not of fragments lacking the C-terminal region, could reduce tumor growth in murine models of fibrosarcoma, mammary adenocarcinoma, Lewis lung carcinoma, and primary and metastatic melanoma, with U-shaped dose-response curves. Tumor growth inhibition was associated with reduction of microvessel density and blood flow in neoplastic tissues. Neutralization of endogenous CgA with antibodies against its C-terminal region (residues 410-439) promoted tumor growth. Structure-function studies showed that the C-terminal region of CgA contains a bioactive site and that cleavage of this region causes a marked loss of anti-angiogenic and anti-tumor potency. Mechanistic studies showed that full-length CgA could induce, with a U-shaped dose-response curve, the production of protease nexin-1 in endothelial cells, a serine protease inhibitor endowed of anti-angiogenic activity. Gene silencing or neutralization of protease nexin-1 with specific antibodies abolished both anti-angiogenic and anti-tumor effects of CgA. These results suggest that circulating full-length CgA is an important inhibitor of angiogenesis and tumor growth, and that cleavage of its C-terminal region markedly reduces its activity. Pathophysiological changes in CgA blood levels and/or its fragmentation might regulate disease progression in cancer patients.

Inhibition of chronic lymphocytic leukemia progression by full-length chromogranin A and its N-terminal fragment in mouse models

Chronic lymphocytic leukemia (CLL) is characterized by the accumulation of leukemic B cells in peripheral blood, bone marrow (BM) and lymphoid tissues, and by their recirculation between these compartments. We observed that circulating chromogranin A (CgA) and its N-terminal fragment (called vasostatin-1, CgA_1-76), two neuroendocrine secretory polypeptides that enhance the endothelial barrier function, are present in variable amounts in the blood of CLL patients. Studies in animal models showed that daily administration of full-length human CgA_1-439 (0.3 μg, i.v., or 1.5 μg/mouse, i.p.) can reduce the BM/blood ratio of leukemic cells in Eμ-TCL1 mice, a transgenic model, and decrease BM, lung and kidney infiltration in Rag2^−/−γc^−/− mice engrafted with human MEC1 CLL cells, a xenograft model. This treatment also reduced the loss of body weight and improved animal motility. In vitro, CgA enhanced the endothelial barrier integrity and the trans-endothelial migration of MEC1 cells, with a bimodal dose-response curve. Vasostatin-1, but not a larger fragment consisting of N-terminal and central regions of CgA (CgA_1-373), inhibited CLL progression in the xenograft model, suggesting that the C-terminal region is crucial for CgA activity and that the N-terminal domain contains a site that is activated by proteolytic cleavage. These findings suggest that circulating full-length CgA and its fragments may contribute to regulate leukemic cell trafficking and reduce tissue infiltration in CLL.

Columnar Metaplasia in the Esophageal Remnant After Esophagectomy: A Common Occurrence and a Valuable Insight Into the Development of Barrett Esophagus

OBJECTIVE

This study aimed to establish the incidence of postesophagectomy columnar metaplasia and dysplasia, and the timescale over which it develops. It also aimed to assess if this epithelium is molecularly similar to sporadic Barrett esophagus, thereby confirming suitability as a research model.

BACKGROUND

Metaplasia in the esophageal remnant after esophagectomy is well described, but incidence and the potential for dysplasia are uncertain, and the clinical relevance unclear. Although proposed as a model for Barrett esophagus, no large studies have examined the molecular phenotype of postesophagectomy metaplasia.

METHODS

Patients underwent prospective endoscopic evaluation having previously undergone esophagectomy. The macroscopic appearance of the esophageal remnant was noted and biopsies taken. Specimens were stained using hematoxylin and eosin and by immunohistochemistry for cytokeratins 7 and 20, and Chromogranin A-proteins which have a well described expression pattern in sporadic Barrett esophagus.

RESULTS

Of the 126 eligible patients, 45 (36%) had evidence of metaplasia. There were no cases of dysplasia. Nonintestinalized columnar epithelium occurred earlier than specialized intestinal metaplasia (median 4.8 vs 8.1 yr; P = 0.025). Thirty-seven samples underwent immunohistochemical analysis. A classic cytokeratin 7/20 staining pattern was present in 23 cases (62%), within the prevalence range reported for sporadic Barrett.

CONCLUSIONS

Columnar metaplasia is common following esophagectomy, but the absence of dysplasia in this large cohort is reassuring. Presence of specialized intestinal metaplasia is associated with increased time from surgery, suggesting this represents later disease. Immunohistochemistry staining is similar to sporadic Barrett, suggesting that this group of patients represent an accurate human model for the development of Barrett.

Chromogranin A as a valid marker in oncology: Clinical application or false hopes?

Chromogranin A, due to its primary expression throughout the neuroendocrine system, is a widely accepted biomarker for the assessment of neuro-endocrine tumors. It has been traditionally used in the management of patients with tumors of gastro-enteropancreatic origin. Lately, it has also been implicated in various conditions and diseases, both benign and malignant. However, the paucity of data of adequate strength, as well as its relation with common physiologic conditions and its interaction with commonly prescribed medications, limit its clinical use in only a narrow spectrum. Herein, we present a thorough review to the most frequent conditions where its levels are affected, focusing specifically on its potential use as a prognostic and predictive biomarker in oncology.

Plasma levels of vasostatin-1, a chromogranin A fragment, are associated with carotid artery maximum stenosis: A pilot study

BACKGROUND

Chromogranin A (CgA), a circulating protein released by the neuroendocrine system, can regulate vascular physiology and angiogenesis. Full-length CgA (CgA_1-439) and its fragment CgA_1-76 (called vasostatin-1, VS-1) preserve the physiological integrity of the endothelial barrier function and are antiangiogenic, whereas CgA_1-373 is proangiogenic. We investigated whether these polypeptides are altered in patients with various degrees of carotid artery atherosclerosis.

METHODS

We studied 81 patients with carotid artery atherosclerosis, asymptomatic for cerebrovascular diseases. Carotid arteries were examined by Doppler ultrasound and plaque characteristics were recorded. Plasma levels of CgA_1-439, VS-1, CgA_1-373, and total-CgA (CgA_1-439 plus truncated fragments lacking part or the entire C-terminal region) were assessed by specific ELISAs.

RESULTS

Plasma levels of VS-1 and total-CgA correlated with carotid artery maximum stenosis (r=0.349, p=0.001 and r=0.256, p=0.021, respectively). Stepwise multiple regression analysis indicated that VS-1 was a significant predictor of maximum stenosis after adjustment for age, gender, and conventional risk factors for atherosclerosis (regression coefficient=12.42, SE=4.84, p=0.012). In addition, logistic regression analysis indicated that relatively high levels of full-length CgA, but not total-CgA, predict the presence of hypoechoic, lipid-rich plaques (OR=1.47; 95% CI: 1.19-1.81, p=0.0003).

CONCLUSION

VS-1 is independently associated with carotid artery maximum stenosis. Furthermore, full-length CgA is an independent indicator of hypoechoic plaques, likely reflecting initial stages of atherosclerosis. Given the known capability of CgA and VS-1 to regulate vascular function and angiogenesis these polypeptides might play a role in the regulation of atherosclerosis pathophysiology.

Randomised trial of the effect of a gastrin/CCK2 receptor antagonist on esomeprazole-induced hypergastrinaemia: evidence against rebound hyperacidity

PURPOSE

Hypergastrinaemia induced by proton pump inhibitor (PPI) therapy may cause ECL-cell and parietal-cell hyperplasia and rebound hyperacidity and dyspepsia after PPI withdrawal. The aim of the study was to assess the effect of different dosage-regimens of netazepide, a gastrin/CCK₂ receptor antagonist, on PPI-induced hypergastrinaemia and elevated chromogranin A (CgA).

METHODS

Six groups of eight healthy subjects participated in a randomised, double-blind study of esomeprazole 40 mg daily for 28 days, in combination with netazepide 1, 5 or 25 mg or placebo, daily, during the last 14 days of esomeprazole or during 14 days after treatment withdrawal. Fasting serum gastrin and plasma CgA were measured during treatment and after withdrawal, as biomarkers of acid suppression and ECL-cell activity, respectively. Dyspepsia was monitored throughout the study.

RESULTS

Esomeprazole increased gastrin and CgA. Netazepide increased gastrin, but not CgA, and inhibited dose dependently the CgA response to esomeprazole. Gastrin and CgA returned to baseline within 2-3 days of esomeprazole withdrawal; netazepide did not shorten that time. There was no rebound dyspepsia after esomeprazole withdrawal.

CONCLUSIONS

Esomeprazole and netazepide each increase gastrin, consistent with a secondary effect of gastric acid suppression, but by different mechanisms. Esomeprazole-induced hypergastrinaemia stimulates ECL cells and thereby increases CgA. Netazepide-induced hypergastrinaemia does not increase CgA, because netazepide blocks gastrin/CCK₂ receptors on ECL cells. Co-administration of netazepide 5 mg abolishes the effect of esomeprazole-induced hypergastrinaemia on ECL cells. The quick return to baseline of gastrin and CgA and absence of dyspepsia after esomeprazole withdrawal do not support the concept of rebound hyperacidity.

Chromogranin A as biomarker in diabetes

Chromogranin A (CgA) is an established plasma marker of neuroendocrine tumors and has been suggested to also have a role as biomarker in other diseases. Whether CgA has any role as biomarker in diabetes is, however, unresolved, but its widespread distribution in the secretory granules in endocrine tissues including β cells and α cells in pancreas, and the metabolic effects of its peptide fragments suggest that CgA may play a pathophysiological role in diabetes, and thus also be a potential diabetes biomarker. In this review, we summarize the available information on CgA and some of its functional post-translational cleavage products in diabetes, followed by a discussion of its potential as a plasma marker in diabetes and the methodological concerns involved.

Chromogranin-A production and fragmentation in patients with Takayasu arteritis

BACKGROUND

Chromogranin-A (CgA) is a secretory protein processed into peptides that regulate angiogenesis and vascular cells activation, migration and proliferation. These processes may influence arterial inflammation and remodelling in Takayasu arteritis (TA).

METHODS

Plasma levels of full-length CgA (CgA439), CgA fragments lacking the C-terminal region (CgA-FRs) and the N-terminal fragment, CgA1-76 (vasostatin-1, VS-1) were analysed in 42 patients with TA and 20 healthy age-matched controls. Vascular remodelling was longitudinally assessed by imaging. CgA peptides were related to markers of systemic and local inflammation, disease activity and vascular remodelling.

RESULTS

Levels of CgA-FRs and VS-1 were increased in TA. Treatment with proton-pump inhibitors (PPIs) and arterial hypertension partially accounted for CgA levels and high inter-patient variability. CgA439, CgA-FRs and VS-1 levels did not reflect disease activity or extent. Markers of systemic or local inflammation correlated with higher CgA-FRs and VS-1 in normotensive patients and with higher CgA439 in hypertensive patients. Treatment with non-biologic anti-rheumatic agents was associated with increased CgA-FRs and a distinctive regulation of CgA processing. Reduced blood levels of anti-angiogenic CgA peptides were associated with vascular remodelling in the groups of patients on PPIs and with arterial hypertension.

CONCLUSIONS

The plasma levels of CgA fragments are markedly increased in TA as a consequence of disease- and therapy-related variables. Anti-angiogenic forms of CgA may limit vascular remodelling. Given the effect of the various CgA peptides, it is advisable to limit the therapeutic prescriptions that might influence CgA-derived peptide levels to clearly agreed medical indications until further data become available.

Chromogranin A Is Preferentially Cleaved into Proangiogenic Peptides in the Bone Marrow of Multiple Myeloma Patients

Angiogenesis has been postulated to be critical for the pathogenesis of multiple myeloma, a neoplastic disease characterized by abnormal proliferation of malignant plasma cells in the bone marrow (BM). Cleavage of the N- and C-terminal regions of circulating chromogranin A (CgA, CHGA), classically an antiangiogenic protein, can activate latent antiangiogenic and proangiogenic sites, respectively. In this study, we investigated the distribution of CgA-derived polypeptides in multiple myeloma patients and the subsequent implications for disease progression. We show that the ratio of pro/antiangiogenic forms of CgA is altered in multiple myeloma patients compared with healthy subjects and that this ratio is higher in BM plasma compared with peripheral plasma, suggesting enhanced local cleavage of the CgA C-terminal region. Enhanced cleavage correlated with increased VEGF and FGF2 BM plasma levels and BM microvascular density. Using the Vk*MYC mouse model of multiple myeloma, we further demonstrate that exogenously administered CgA was cleaved in favor of the proangiogenic form and was associated with increased microvessel density. Mechanistic studies revealed that multiple myeloma and proliferating endothelial cells can promote CgA C-terminal cleavage by activating the plasminogen activator/plasmin system. Moreover, cleaved and full-length forms could also counter balance the pro/antiangiogenic activity of each other in in vitro angiogenesis assays. These findings suggest that the CgA-angiogenic switch is activated in the BM of multiple myeloma patients and prompt further investigation of this CgA imbalance as a prognostic or therapeutic target. Cancer Res; 76(7); 1781–91. ©2016 AACR.

Effect of netazepide, a gastrin/CCK2 receptor antagonist, on gastric acid secretion and rabeprazole-induced hypergastrinaemia in healthy subjects

AIMS

To compare gastric acid suppression by netazepide, a gastrin/CCK2 receptor antagonist, with that by a proton pump inhibitor (PPI), and to determine if netazepide can prevent the trophic effects of PPI-induced hypergastrinaemia.

METHODS

Thirty healthy subjects completed a double-blind, randomized, parallel group trial of oral netazepide and rabeprazole, alone and combined, once daily for 6 weeks. Primary end points were: basal and pentagastrin-stimulated gastric acid and 24 h circulating gastrin and chromogranin A (CgA) at baseline, start and end of treatment, gastric biopsies at baseline and end of treatment and basal and pentagastrin-stimulated gastric acid and dyspepsia questionnaire after treatment withdrawal.

RESULTS

All treatments similarly inhibited pentagastrin-stimulated gastric acid secretion. All treatments increased serum gastrin, but the combination and rabeprazole did so more than netazepide alone. The combination also reduced basal acid secretion. Rabeprazole increased plasma CgA, whereas netazepide and the combination reduced it. None of the biopsies showed enterochromaffin-like (ECL) cell hyperplasia. Withdrawal of treatments led neither to rebound hyperacidity nor dyspepsia.

CONCLUSIONS

Netazepide suppressed pentagastrin-stimulated gastric acid secretion as effectively as did rabeprazole. The reduction in basal acid secretion and greater increase in serum gastrin by the combination is consistent with more effective acid suppression. Despite our failure to show rabeprazole-induced ECL cell hyperplasia and rebound hyperacidity, the increase in plasma CgA after rabeprazole is consistent with a trophic effect on ECL cells, which netazepide prevented. Thus, netazepide is a potential treatment for the trophic effects of hypergastrinaemia and, with or without a PPI, is a potential treatment for acid-related conditions.

Systematic review: the effects of long-term proton pump inhibitor use on serum gastrin levels and gastric histology

BACKGROUND

Proton pump inhibitors (PPIs) have a well-established safety profile. However, concerns have been raised about a potential relationship between PPI-induced hypergastrinaemia and the development of enterochromaffin-like (ECL) cell hyperplasia, neuroendocrine tumours and gastric cancer during long-term therapy.

AIM

To review the effects of long-term PPI use on serum gastrin levels and gastric histopathology.

METHODS

A systematic literature search was conducted in PubMed on 21 April 2015 to identify studies reporting the effects of long-term (defined as >3 years) PPI use on gastrin levels and gastric histopathology.

RESULTS

A total of 16 studies (1920 patients) met the inclusion criteria. During long-term PPI therapy, mean gastrin levels rose to one to three times the upper limit of the normal range (~100 pg/mL), and an increased prevalence of ECL cell hyperplasia was observed (+7.8-52.0%). Helicobacter pylori-positive patients had a significantly increased risk of developing ECL linear/micronodular hyperplasia compared with H. pylori-negative patients [OR: 2.45 (95% CI: 1.47-4.10), P = 0.0006]; however, no evidence of neoplastic changes was found. The risk of corpus atrophy was markedly higher in H. pylori-positive patients than in H. pylori-negative patients [OR: 11.45 (95% CI: 6.25-20.99), P < 0.00001]. Not a single case of gastric adenocarcinoma was found.

CONCLUSIONS

Long-term PPI therapy induced moderate hypergastrinaemia in most patients and an increased prevalence of ECL cell hyperplasia. H. pylori-positive patients receiving long-term PPI therapy were exposed to a higher risk of corpus atrophy than H. pylori-negative patients. No neuroendocrine tumours or gastric cancers were found.

Long-term proton pump inhibitor (PPI) use and the development of gastric pre-malignant lesions

BACKGROUND

Proton pump inhibitors (PPIs) are the most effective drugs to reduce gastric acid secretion. PPIs are one of the most commonly prescribed classes of medications worldwide. Apart from short-term application, maintenance therapy with PPIs is recommended and increasingly used in certain diseases, such as Zollinger-Ellison syndrome and gastro-oesophageal reflux disease, especially for people with erosive oesophagitis or Barrett's oesophagus. Although PPIs are generally safe, their efficacy and safety of long-term use remains unclear. The question of whether the long-term use of PPIs could promote the development of gastric pre-malignant lesions has been widely investigated, but results are inconsistent. Limited insight on this problem leads to a dilemma in decision making for long-term PPI prescription.

OBJECTIVES

To compare the development or progression of gastric pre-malignant lesions, such as atrophic gastritis, intestinal metaplasia, enterochromaffin-like (ECL) cell hyperplasia, and dysplasia, in people taking long-term (six months or greater) PPI maintenance therapy.

SEARCH METHODS

We searched the following databases (from inception to 6 August 2013): the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and CINAHL. In addition, we searched the reference lists of included trials and contacted experts in the field.

SELECTION CRITERIA

We searched for randomised controlled trials (RCTs) in adults (aged 18 years or greater) concerning the effects of long-term (six months or greater) PPI use on gastric mucosa changes, confirmed by endoscopy or biopsy sampling (or both).

DATA COLLECTION AND ANALYSIS

Two review authors independently performed selection of eligible trials, assessment of trial quality, and data extraction. We calculated odds ratios (OR) for analysis of dichotomous data and mean differences for continuous data, with 95% confidence intervals (CI).

MAIN RESULTS

We included seven trials (1789 participants). Four studies had high risk of bias and the risk of bias in the other three trials was unclear. In addition, it was difficult to assess possible reporting bias. We pooled 1070 participants from four RCTs to evaluate corporal atrophy development revealing an insignificantly increased OR of 1.50 (95% CI 0.59 to 3.80; P value = 0.39; low-quality evidence) for long-term PPI users relative to non-PPI users. In five eligible trials, corporal intestinal metaplasia was assessed among 1408 participants, also with uncertain results (OR 1.46; 95% CI 0.43 to 5.03; P value = 0.55; low-quality evidence). However, by pooling data of 1705 participants from six RCTs, our meta-analysis showed that participants with PPI maintenance treatment were more likely to experience either diffuse (simple) (OR 5.01; 95% CI 1.54 to 16.26; P value = 0.007; very-low-quality evidence) or linear/micronodular (focal) ECL hyperplasia (OR 3.98; 95% CI 1.31 to 12.16; P value = 0.02; low-quality evidence) than controls. No participant showed any dysplastic or neoplastic change in any included studies.

AUTHORS' CONCLUSIONS

There is presently no clear evidence that the long-term use of PPIs can cause or accelerate the progression of corpus gastric atrophy or intestinal metaplasia, although results were imprecise. People with PPI maintenance treatment may have a higher possibility of experiencing either diffuse (simple) or linear/micronodular (focal) ECL cell hyperplasia. However, the clinical importance of this outcome is currently uncertain.

A PCR blood test outperforms chromogranin A in carcinoid detection and is unaffected by proton pump inhibitors

A critical requirement in neuroendocrine tumor (NET) management is a blood biomarker test that is sensitive, specific and reproducible. We evaluated a PCR-based 51-transcript signature to detect tumors, compared it with chromogranin A (CgA) and examined the confounding effect of proton pump inhibitors (PPIs), which cause falsely elevated CgA levels. The multigene signature was evaluated in two groups. Group 1: 125 prospectively collected NETs: gastroenteropancreatic NETs (n=91, including 42 pancreatic and 40 small intestinal), carcinoids of unknown primary (n=18) and other sites (n=16). Group 2: prospectively collected non-NET patients receiving PPIs (>1 month; dyspepsia, n=19; GERD, n=6; and pancreatitis, n=4) and 50 controls. All samples were analyzed by PCR (marker genes) and ELISA (DAKO-CgA). Sensitivity comparisons included χ(2), non-parametric measurements, and receiver operating characteristic (ROC) curves. Group 1: 123 NETs were PCR-positive (98.4%) compared with 50 (40%) CgA-positive (χ(2)=97.3, P<10(-26)). Significant differences (P<0.001) were noted between pancreas: PCR 95% vs CgA 29.2% (P<10(-9)) and small intestine: 100 vs 58% (P<10(-4)). The multigene test was elevated in all grades (G1-G3), in both local and disseminated disease, and was not normalized by somatostatin analog therapy. It was also elevated in 97% of CgA normal NETs. Group 2: PPI administration increased CgA in 83% and CgA was elevated in 26% of controls. PCR values were not elevated in either group. PCR performance metrics were as follows: sensitivity 98.4%, specificity 100%, positive predictive value 100%, negative predictive value 97.8%, and the ROC-derived area under the curve (AUC) was 0.997. These were significantly better than CgA (all metrics <60%; AUC, 0.54; Z-statistic, 10.44, P<0.0001). A 51-panel multigene blood transcript analysis is significantly more sensitive than plasma CgA for NET detection and is unaffected by acid suppression therapy.

The effect of duodenojejunostomy and sleeve gastrectomy on type 2 diabetes mellitus and gastrin secretion in Goto-Kakizaki rats

BACKGROUND

Bariatric surgery is a highly effective treatment of type 2 diabetes in patients with morbid obesity. The weight-loss independent improvement of glycemic control observed after these procedures has led to the discussion whether bariatric surgery can be introduced as treatment for type 2 diabetes in patients with a body mass index < 35 kg/m(2). We have studied the effects of two bariatric procedures on type 2 diabetes and on gastrointestinal hormone secretion in a lean diabetic animal model.

METHODS

Male Goto-Kakizaki rats, 17-18 weeks old, were randomized into three groups: duodenojejunostomy (DJ), sleeve gastrectomy (SG), or sham operation. During 36 postoperative weeks we evaluated body weight, fasting blood glucose, glucose tolerance, insulin, HbA1c, glucagon-like peptide 1, cholesterol parameters, triglycerides, total ghrelin, and gastrin.

RESULTS

Oral glucose tolerance was significantly improved for both DJ and SG at four weeks after surgery (p < 0.05). At the 34th postoperative week, SG had significantly lower area under the curve during oral glucose tolerance test compared to sham (p = 0.007). SG had significantly lower HbA1c compared to sham at 12 weeks; (mean ± SEM) 4.3 ± 0.1 % versus 5.2 ± 0.3 % (p < 0.05) and compared to both DJ and sham 34 weeks after surgery [median (75 %;25 %)] 5.2 (6.0; 4.3) % versus 7.0 (7.5; 6.7) % and 7.3 (7.6; 6.7) % (p = 0.009). Serum gastrin levels were markedly elevated for SG compared to DJ and sham; 188.0 (318.0; 121.0) versus 77.5 (114.0; 58.0) and 68.0 (90.0; 59.5) pmol/L (p = 0.004) at six weeks and 192.0 (587.8; 110.8) versus 65.5 (77.0; 59.0) and 69.5 (113.0; 55.5) (p = 0.001) 36 weeks after surgery.

CONCLUSION

Sleeve gastrectomy induces hypergastrinemia, lowers HbA1c, and improves glycemic control in Goto-Kakizaki rats. Sleeve gastrectomy is superior to duodenojejunostomy as treatment of type 2 diabetes mellitus in this animal model.

Chromogranin A as a biomarker of disease activity and biologic therapy in inflammatory bowel disease: a prospective observational study

OBJECTIVE

To access the correlation of Chromogranin A (CgA) with inflammatory bowel disease (IBD) activity and responsiveness to medical therapy.

MATERIAL AND METHODS

A prospective observational study was conducted in 56 patients with moderate ulcerative colitis (UC) or Crohn's disease (CD) (UC, n = 29, CD, n = 27), 17 patients with irritable bowel syndrome and predominant diarrhea (IBS-D) and 40 healthy volunteers. IBD patients were treated by biologics (infliximab or adalimumab) or conventional agents (aminosalicylates, thiopurines or methotrexate and steroids) and were classified according to their treatment in two groups. Serum CgA was measured at baseline and 4-week posttreatment period.

RESULTS

Serum CgA was significantly higher in IBD patients than in those with IBS-D or healthy volunteers (p < 0.01). Furthermore, serum CgA was markedly increased in CD patients than in UC patients (p < 0.01). CgA value was significantly reduced in 'biologic' group (24 IBD patients, UC, n = 15, CD, n = 9) at 4-week posttreatment period (p < 0.01), while 18/24 (72%) patients were already in remission during that time. In contrast, CgA value was significantly increased in the 'conventional' treatment group (32 IBD patients, UC, n = 14, CD, n = 18) between the two visits (p < 0.01), although 22/32 (69%) patients were in remission during the 4-week posttreatment period.

CONCLUSION

CgA appears to be a reliable marker of disease activity in IBD patients and especially in those who received biologic therapy. IBS-D patients presented normal CgA values.

A concise, practical guide to diagnostic assessment for mast cell activation disease

As recognition of mast cell (MC) involvement in a range of chronic inflammatory disorders has increased, diagnosticians’ suspicions of MC activation disease (MCAD) in their chronically mysteriously inflamed patients have similarly increased. It is now understood that the various forms of systemic mastocytosis - diseases of inappropriate activation and proliferation of MCs seemingly driven by a small set of rare, usually constitutively activating mutations in assorted MC regulatory elements - comprise merely the tip of the MCAD iceberg, whereas the far larger and far more clinically heterogeneous (and thus more difficult to recognize) bulk of the iceberg consists of assorted forms of MC activation syndrome (MCAS) which manifest little to no abnormal MC proliferation and may originate from a far more heterogeneous set of MC mutations. It is reasonable to suspect MCAD when symptoms and signs of MC activation are present and no other diagnosis better accounting for the full range of findings is present. Initial laboratory assessment should include not only routine blood counts and serum chemistries but also a serum total tryptase level, which helps direct further evaluation for mastocytosis vs MCAS. Appropriate tissue examinations are needed to diagnose mastocytosis, while elevated levels of relatively specific mast cell mediators are sought to support diagnosis of MCAS. Whether assessing for mastocytosis or MCAS, testing is fraught with potential pitfalls which can easily yield false negatives leading to erroneous rejection of diagnostic consideration of MCAD in spite of a clinical history highly consistent with MCAD. Efforts at accurate diagnosis of MCAD are worthwhile, as many patients then respond well to appropriately directed therapeutic efforts.

A concise, practical guide to diagnostic assessment for mast cell activation disease

As recognition of mast cell (MC) involvement in a range of chronic inflammatory disorders has increased, diagnosticians’ suspicions of MC activation disease (MCAD) in their chronically mysteriously inflamed patients have similarly increased. It is now understood that the various forms of systemic mastocytosis - diseases of inappropriate activation and proliferation of MCs seemingly driven by a small set of rare, usually constitutively activating mutations in assorted MC regulatory elements - comprise merely the tip of the MCAD iceberg, whereas the far larger and far more clinically heterogeneous (and thus more difficult to recognize) bulk of the iceberg consists of assorted forms of MC activation syndrome (MCAS) which manifest little to no abnormal MC proliferation and may originate from a far more heterogeneous set of MC mutations. It is reasonable to suspect MCAD when symptoms and signs of MC activation are present and no other diagnosis better accounting for the full range of findings is present. Initial laboratory assessment should include not only routine blood counts and serum chemistries but also a serum total tryptase level, which helps direct further evaluation for mastocytosis vs MCAS. Appropriate tissue examinations are needed to diagnose mastocytosis, while elevated levels of relatively specific mast cell mediators are sought to support diagnosis of MCAS. Whether assessing for mastocytosis or MCAS, testing is fraught with potential pitfalls which can easily yield false negatives leading to erroneous rejection of diagnostic consideration of MCAD in spite of a clinical history highly consistent with MCAD. Efforts at accurate diagnosis of MCAD are worthwhile, as many patients then respond well to appropriately directed therapeutic efforts.

The effects of long-term therapy with proton pump inhibitors on meal stimulated gastrin

BACKGROUND

Dyspepsia develops in healthy volunteers after withdrawal of proton-pump inhibitors. This phenomenon, attributed to rebound acid hypersecretion, is thought to be mediated by reflex hypergastrinemia.

AIMS

To measure fasting and postprandial gastrin in patients on long-term proton-pump inhibitor treatment and correlate gastrin levels with the duration of treatment and other potential predictors.

METHODS

In this cross sectional study patients, with erosive esophagitis, on long-term proton-pump inhibitor treatment and healthy controls underwent gastrin measurements at baseline and four times following a meal and Helicobacter pylori status was determined.

RESULTS

A total of 100 patients and 50 controls were studied. Pre- and postprandial gastrin levels were higher in patients (p<0.001). No significant correlation was found between the area under the gastrin-curve and the treatment duration. Female patients had significantly higher gastrin levels than males pre- and postprandial, whereas such differences was not found in the control group. Female gender was the only independent predictor of s-gastrin levels (OR 2.50 compared to males, 95% CI: 1.08-5.76, p=0.032) in the patient group.

CONCLUSION

Gastrin values were higher in patients compared to controls. There was no correlation between gastrin levels and treatment duration. Female patients had significantly higher gastrin values than males.

Plasma chromogranin A after severe burn trauma

BACKGROUND

Chromogranin A (CgA) in plasma (P-CgA), a neuroendocrine marker of sympathetic stress, has been shown to predict mortality in medical intensive care. We hypothesized that the magnitude of CgA release would reflect stress load, and thereby injury severity in burn intensive care patients.

METHODS

Fifty-one consecutive patients with a burn area exceeding 10% were included. P-CgA was measured twice daily for seven days after injury. The point value at 24h, the mean and maximum values and the AUC at days 1-7, were tested as possible predictors. Injury severity in the form of organ dysfunction was measured as SOFA score at day 7.

RESULTS

P-CgA could be classified into two types with respect to variability over time. Patients with high variability had more deep injuries and were older than those with low variability. All measures of CgA correlated with SOFA score at day 7, but not with total burn size. Univariate regressions showed that age, burn size and three of four measures of P-CgA predicted organ dysfunction. Multiple regressions showed that age, burn size, and either P-CgA at 24h, the mean value up to day 7, or the maximum value up to day 7, were independent predictors for organ dysfunction. Significant organ dysfunction was best predicted by age, burn area and the CgA point value at 24h with an AUC value of 0.91 in a ROC-analysis.

CONCLUSIONS

The extent of neuroendocrine activation assessed as P-CgA after a major burn injury is independently related to organ dysfunction.

Safety of long-term PPI therapy

Proton pump inhibitors have become the mainstay of medical treatment of acid-related disorders. Long-term use is becoming increasingly common, in some cases without a proper indication. A large number of mainly observational studies on a very wide range of possible associations have been published in the past decade and are critically reviewed in this article and the existing evidence is evaluated and translated into possible clinical consequences. Based on the existing evidence the benefits of PPI treatment seem to outweigh potential risks in the large majority of patients especially if PPI use is based on a relevant indication. The concern for complications should primarily be directed at elderly, malnourished with significant co-morbidity. In this population an increased risk for enteric infections, fractures and nutritional deficiencies might have clinical consequences and should lead to a careful evaluation of the indication for PPI treatment.

18F-fluorodihydroxyphenylalanine vs other radiopharmaceuticals for imaging neuroendocrine tumours according to their type

6-Fluoro-(¹⁸F)-L-3,4-dihydroxyphenylalanine (FDOPA) is an amino acid analogue for positron emission tomography (PET) imaging which has been registered since 2006 in several European Union (EU) countries and by several pharmaceutical firms. Neuroendocrine tumour (NET) imaging is part of its registered indications. NET functional imaging is a very competitive niche, competitors of FDOPA being two well-established radiopharmaceuticals for scintigraphy, ¹²³I-metaiodobenzylguanidine (MIBG) and ¹¹¹In-pentetreotide, and even more radiopharmaceuticals for PET, including fluorodeoxyglucose (FDG) and somatostatin analogues. Nevertheless, there is no universal single photon emission computed tomography (SPECT) or PET tracer for NET imaging, at least for the moment. FDOPA, as the other PET tracers, is superior in diagnostic performance in a limited number of precise NET types which are currently medullary thyroid cancer, catecholamine-producing tumours with a low aggressiveness and well-differentiated carcinoid tumours of the midgut, and in cases of congenital hyperinsulinism. This article reports on diagnostic performance and impact on management of FDOPA according to the NET type, emphasising the results of comparative studies with other radiopharmaceuticals. By pooling the results of the published studies with a defined standard of truth, patient-based sensitivity to detect recurrent medullary thyroid cancer was 70 % [95 % confidence interval (CI) 62.1–77.6] for FDOPA vs 44 % (95 % CI 35–53.4) for FDG; patient-based sensitivity to detect phaeochromocytoma/paraganglioma was 94 % (95 % CI 91.4–97.1) for FDOPA vs 69 % (95 % CI 60.2–77.1) for ¹²³I-MIBG; and patient-based sensitivity to detect midgut NET was 89 % (95 % CI 80.3–95.3) for FDOPA vs 80 % (95 % CI 69.2–88.4) for somatostatin receptor scintigraphy with a larger gap in lesion-based sensitivity (97 vs 49 %). Previously unpublished FDOPA results from our team are reported in some rare NET, such as small cell prostate cancer, or in emerging indications, such as metastatic NET of unknown primary (CUP-NET) or adrenocorticotropic hormone (ACTH) ectopic production. An evidence-based strategy in NET functional imaging is as yet affected by a low number of comparative studies. Then the suggested diagnostic trees, being a consequence of the analysis of present data, could be modified, for some indications, by a wider experience mainly involving face-to-face studies comparing FDOPA and ⁶⁸Ga-labelled peptides.

Inappropriate prescribing of proton pump inhibitors in older patients: effects of an educational strategy

BACKGROUND

An increasing number of older patients are prescribed proton pump inhibitors (PPIs). However, the extent of inappropriate PPI prescribing in this group is largely unknown.

OBJECTIVE

We sought to identify clinical and demographic factors associated with inappropriate PPI prescribing in older patients and to assess the effects of a targeted educational strategy in a controlled hospital environment.

METHODS

Clinical and demographic characteristics and full medication exposure on admission were recorded in 440 consecutive older patients (mean ± SD age 84 ± 7 years) admitted to a teaching hospital between 1 February 2011 and 30 June 2011. A 4-week educational strategy to reduce inappropriate PPI prescribing during hospital stay, either by stopping or reducing PPI doses, was conducted within the study period. The main outcome measures of the study were the incidence of inappropriate PPI prescribing and the effects of interventions to reduce it.

RESULTS

On admission, PPIs were established therapy in 164 patients (37%). This was considered inappropriate in 100 patients (61%). Lower Charlson Comorbidity Index score (odds ratio [OR] 0.76; 95% CI 0.57, 0.94; p = 0.006) and history of dementia (OR 1.65; 95% CI 1.28, 1.83; p = 0.005) were independently associated with inappropriate PPI prescribing. Interventions to reduce inappropriate PPI prescribing occurred more frequently during and after the education phase (frequency of interventions in patients with inappropriate PPI prescribing: pre-education phase 9%, during education phase 43%, and post-education phase 46%, p = 0.006). Prescribing interventions were not associated with acid rebound symptoms.

CONCLUSIONS

Inappropriate PPI prescribing in older patients is frequent and independently associated with co-morbidities and dementia. A targeted in-hospital educational strategy can significantly and safely reduce inappropriate PPI prescribing in the short term.

Chromogranin A regulates tumor self-seeding and dissemination

Cancer progression involves the seeding of malignant cells in circulation and the colonization of distant organs. However, circulating neoplastic cells can also reinfiltrate the tumor of origin. This process, called "tumor-self seeding," can select more aggressive cells that may contribute to cancer progression. Here, using mouse mammary adenocarcinoma models, we observed that both tumor self-seeding and organ colonization were inhibited by chromogranin A (CgA), a protein present in variable amounts in the blood of cancer patients. Mechanism studies showed that CgA inhibited the shedding of cancer cells in circulation from primary tumors, as well as the reinfiltration of tumors and the colonization of lungs by circulating tumor cells. CgA reduced gap formation induced by tumor cell-derived factors in endothelial cells, decreased vascular leakage in tumors, and inhibited the transendothelial migration of cancer cells. Together, our findings point to a role for circulating CgA in the regulation of tumor cell trafficking from tumor-to-blood and from blood-to-tumor/normal tissues. Inhibition of the multidirectional trafficking of cancer cells in normal and neoplastic tissues may represent a novel strategy to reduce cancer progression.

Discontinuation of proton pump inhibitors during assessment of chromogranin A levels in patients with neuroendocrine tumours

Background:

The aim of this prospective study was to examine whether discontinuation of proton pump inhibitors (PPIs) or replacement by H₂-receptor antagonists (H2RA) resulted in a decrease of chromogranin A (CgA) levels in 196 patients with well-differentiated neuroendocrine tumours (NETs).

Methods:

Patients with an unexpectedly high CgA level not connected with NET disease discontinued PPIs, or used H2RA instead; 2 weeks later CgA level was measured again.

Results:

In all, 19 out of 196 (10%) patients showed unexpected elevated CgA levels, they all used PPI. In 11 out of 19 patients with no evidence of the disease, median CgA decreased from 390 μg l⁻¹ during PPI treatment to 56 μg l⁻¹ after discontinuation (P=0.003). In 8 out of 19 patients with stable disease, median CgA decreased from 618 to 318 μg l^–1 (P=0.012). In 12 out of 19 patients who ceased all acid inhibition, CgA levels decreased by 82%, while in the seven patients who replaced PPI by H2RA, CgA decreased by 77% (P=0.967).

Conclusion:

Proton pump inhibitor use causes falsely elevated CgA levels in patients with NET. We recommend to stop, or replace PPI by H2RA, to obtain a reliable CgA value.

Withdrawing PPI therapy after healing esophagitis does not worsen symptoms or cause persistent hypergastrinemia: analysis of dexlansoprazole MR clinical trial data

OBJECTIVES

Withdrawal of proton pump inhibitors (PPIs) may induce symptoms in healthy volunteers, suggesting that discontinuing PPI therapy induces acid-peptic disease. Similar assessments in patients with documented acid-related disorders are lacking.

METHODS

We performed a retrospective analysis of data from 287 Helicobacter pylori-negative erosive esophagitis (EE) patients healed after 4 or 8 weeks of therapy with dexlansoprazole modified release (MR) or lansoprazole, and then randomized to placebo in 6-month maintenance trials. We compared serum gastrin levels and 24-h heartburn severity before enrollment in the healing trials (baseline) and after receiving placebo in the 6-month maintenance trials.

RESULTS

Mean gastrin values at maintenance months 1 and 3 were essentially unchanged (median changes, 1.0 and -1.0 pg/ml), showing that gastrin normalized within 1 month of discontinuing PPIs and remained flat. Mean heartburn severity at maintenance month 1 was <1 on a 5-point scale (1=mild) and significantly lower than at baseline (median decrease, 0.41 points; P≤0.001). Heartburn severity in patients healed at week 4 or 8 with either PPI was generally similar, suggesting that neither longer exposure nor more potent therapy was associated with rebound. In those with month 2 data, mean heartburn severity at months 1 and 2 was significantly lower than baseline (median decrease, 0.54 and 0.58 points; both P<0.001), indicating an ongoing symptom response for 2 months after PPI withdrawal.

CONCLUSIONS

In H. pylori-negative EE patients, there was no indication of recurring heartburn symptom worsening beyond baseline levels within 2 months of discontinuing 4-8 weeks of PPI therapy.

Increased plasma concentrations of tumour markers in the absence of neoplasia

Tumour markers are a very heterogeneous group of molecules that are generally found in very small concentrations in the plasma and serum of healthy individuals. In the process of neoplastic differentiation the cell can synthesize, release, or induce synthesis of other cells, thus increasing their concentration in plasma and serum. These substances may also increase their plasma concentration in patients without cancer due to processes that increase the release or reduce catabolism, and so give rise to false positives. An understanding of the main physiopathological processes that increase the concentrations of these substances could improve our interpretation of tumour markers and their clinical application. In this study we review the physiopathological processes that may increase the plasma concentrations of tumour markers. We performed a bibliography review in PubMed, searching for causes of false positives for the following tumour markers: α-Fetoprotein, CA 125, CA 15-3, CA 19-9, CA 72-4, carcinoembryonic antigen, CYFRA 21-1, squamous cell carcinoma, prostatic specific antigen, β(2)-microglobulin, choriogonadotropin (β chain), chromogranin A, neuron specific enolase, HER2-neu, progastrin releasing peptide, S-100, and thyroglobulin. The results favour the use of tests which can identify pathological processes that may increase tumour marker concentrations.

Chromogranin A restricts drug penetration and limits the ability of NGR-TNF to enhance chemotherapeutic efficacy

NGR-TNF is a derivative of TNF-α that targets tumor blood vessels and enhances penetration of chemotherapeutic drugs. Because of this property, NGR-TNF is being tested in combination with chemotherapy in various phase II and III clinical trials. Here we report that chromogranin A (CgA), a protein present in variable amounts in the blood of normal subjects and cancer patients, inhibits the synergism of NGR-TNF with doxorubicin and melphalan in mouse models of lymphoma and melanoma. Pathophysiologically relevant levels of circulating CgA blocked NGR-TNF-induced drug penetration by enhancing endothelial barrier function and reducing drug extravasation in tumors. Mechanistic investigations done in endothelial cell monolayers in vitro showed that CgA inhibited phosphorylation of p38 MAP kinase, disassembly of VE-cadherin-dependent adherence junctions, paracellular macromolecule transport, and NGR-TNF-induced drug permeability. In this system, the N-terminal fragment of CgA known as vasostatin-1 also inhibited drug penetration and NGR-TNF synergism. Together, our results suggest that increased levels of circulating CgA and its fragments, as it may occur in certain cancer patients with nonneuroendocrine tumors, may reduce drug delivery to tumor cells particularly as induced by NGR-TNF. Measuring CgA and its fragments may assist the selection of patients that can respond better to NGR-TNF/chemotherapy combinations in clinical trials.

[Complete and sustained remission of liver metastases from neuroendocrine tumor with somatostatin analogue therapy]

Somatostatin analogues represent a major treatment modality in the therapy of neuroendocrine tumors. Their efficacy is well documented in the inhibition of hormone secretion; however, novel data seem to underline their effectiveness in tumor regression, as well. In this report authors present a case of type 1 neuroendocrine tumors of the stomach associated with liver metastases. Somatostatin analogue treatment resulted in a complete regression of the primary tumor and the metastases within two years. This case draws attention on the importance of somatostatin analogue treatment not only in the control of hormonal symptoms but also in the inhibition of tumor growth.