Relationship between ghrelin, Helicobacter pylori and gastric mucosal atrophy in hemodialysis patients

Eradication Therapy for Helicobacter pylori Infection in Patients Receiving Hemodialysis: Review

Patients receiving hemodialysis (HD) often develop gastrointestinal diseases. Recently, although in general population, clinical guidelines for Helicobacter pylori have strongly recommended its eradication in patients to prevent gastric cancer, optimal eradication regimen and optimal dosage of drugs for patients receiving HD have not been established, due to possible incidence of adverse events. Some antimicrobial agents used in eradication therapy, particularly amoxicillin, can exacerbate renal dysfunction. Given the delayed pharmacokinetics of drugs in patients receiving HD compared with those in healthy individuals, drug regimen and dosage should be considered to minimize adverse effects. Although previous studies have investigated the benefits of eradication therapy for patients receiving HD, because most studies were small in terms of the number of enrolled patients, it is hard to show evidence. The numbers of eradication in HD patients have recently increased, and it is important to provide an optimal regimen. The consideration of eradication in patients undergoing HD with a reduction in the drug dose by 1/2-1/3 may prevent adverse events. Additionally, another important consideration is whether adverse events can be prevented while maintaining a similar eradication rate with reduced drug dosages. Recent meta-analysis findings indicate comparable eradication rates in patients receiving HD and healthy individuals, both with the same dosage regimen and at a reduced dosage regimen, with no significant differences (relative risk [RR] for successful eradication: 0.85 [95% confidence interval (CI): 0.48-1.50]). Unlike with the same dosage regimen (RR for adverse events: 3.15 [95% CI: 1.93-5.13]), the adverse events in the dosage reduction regimen were similar to those in healthy individuals (RR: 1.26 [95% CI: 0.23-6.99]). From a pharmacological perspective, the eradication regimen in patients receiving HD should consider the dosage (1/2-1/3 dosage), dosing number (bid), dosing timing of drugs (after HD), and susceptibility to antimicrobial agents.

Gastric organoids: Advancing the study of H. pylori pathogenesis and inflammation

For decades, traditional in vitro and in vivo models used for the study of Helicobacter pylori infection have relied heavily on the use of gastric cancer cell lines and rodents. Major challenges faced by these methods have been the inability to study cancer initiation in already cancerous cell lines, and the difficulty in translating results obtained in animal models due to genetic differences. These challenges have prevented a thorough understanding of the pathogenesis of disease and slowed the development of cancer therapies and a suitable vaccine against the pathogen. In recent years, the development of gastric organoids has provided great advantages over the traditional in vivo and in vitro models due to their similarities to the human stomach in vivo, their ease of use, and the capacity for long-term culture. This review discusses the advantages and limitations of existing in vivo and in vitro models of H. pylori infection, and how gastric organoids have been applied to study H. pylori pathogenesis, with a focus on how the pathogen interacts with the gastric epithelium, inflammatory processes, epithelial repair, and cancer initiation. The potential applications of organoids to address more complex questions on the role of hormones, vaccine-induced immunity are also discussed.

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

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

Gender Differences in Plasma Ghrelin Levels in Hemodialysis Patients

Ghrelin is an orexigenic hormone mainly secreted by the stomach, and it decreases according to the severity of gastric atrophy. Ghrelin has multiple favorable functions, including protein anabolism enhancement, anti-inflammatory activity, and cardiovascular protection, and is associated with survival in hemodialysis (HD) patients. Although the plasma level and role of ghrelin may be different depending on gender, they have not been completely assessed in HD patients. We enrolled 80 (male/female: 51/29) maintenance HD patients. An upper gastrointestinal endoscopic examination was performed for all patients to determine the severity of gastric mucosal atrophy and Helicobacter pylori infection. We measured plasma acyl and desacyl ghrelin levels and assessed the association between ghrelin levels and relevant clinical parameters, including nutrition, inflammation, atherosclerosis, and bone metabolism, by gender. Both acyl and desacyl ghrelin levels in female HD patients were significantly higher than those in male HD patients. When stratified by gastric mucosal atrophy, these gender differences were observed only in patients without gastric atrophy. In female patients, acyl ghrelin level was negatively correlated with age. In male patients, both acyl and desacyl ghrelin levels were positively correlated with bone mineral density. Multiple regression analysis showed significant positive correlations between both ghrelin levels and female gender after adjusting for confounding factors. Plasma ghrelin levels were higher in female HD patients than in male HD patients. The gender difference was more evident in patients without gastric atrophy.

Eradication therapy for Helicobacter pylori infection improves nutrition status in Japanese hemodialysis patients: a pilot study

Plasma ghrelin level is influenced by Helicobacter pylori (H. pylori) status and the severity of gastric mucosal atrophy, and the ghrelin level is associated with nutrition status in hemodialysis patients. Here, we investigated the efficacy of H. pylori eradication therapy in improving nutrition status in relation to the ghrelin level in H. pylori-positive hemodialysis patients. Of H. pylori-positive patients receiving hemodialysis at 8 dialysis center, 21 patients underwent gastroduodenoscopy for evaluation of the severity of gastric atrophy, and nutrition markers and plasma ghrelin levels before and 1 year after H. pylori eradication therapy were evaluated. Serum cholinesterase level was significantly increased after H. pylori eradication compared with the level before eradication (303.2 ± 76.0 vs 287.3 ± 68.1 IU/L, p = 0.029). In particular, cholesterol (before, 196.6 ± 23.2 mg/dl; after, 206.1 ± 25.9 mg/dl, p = 0.042) and cholinesterase levels (before, 296.9 ± 70.8 IU/L; after, 316.4 ± 73.8 IU/L, p = 0.049) increased more strongly in patients with mild–moderate atrophy than those with severe atrophy, irrespective of improvement of plasma acyl-ghrelin and desacyl-ghrelin levels after eradication therapy. In conclusion, H. pylori eradication may improve nutrition status by increasing serum cholinesterase and cholesterol levels in hemodialysis patients, especially those with mild and moderate gastric mucosal atrophy.

Efficacy of Reduced Dosage of Amoxicillin in an Eradication Therapy for Helicobacter pylori Infection in Patients on Hemodialysis: A Randomized Controlled Trial

BACKGROUND

An optimum Helicobacter pylori-eradication regimen for hemodialysis patients is yet to be established because of different pharmacokinetics of amoxicillin involved between hemodialysis patients and healthy subjects. We investigated to establish appropriate doses of amoxicillin for H. pylori infection eradication in hemodialysis patients.

METHODS

Of 409 hemodialysis patients screened for H. pylori infection, 37 H. pylori-positive patients were randomized to different 1-week eradication regimens: esomeprazole 20 mg twice a day (b.i.d.) and clarithromycin 200 mg b.i.d., plus amoxicillin at either 750 mg b.i.d. (group A; conventional) or 250 mg b.i.d. (group B; experimental). Sixty-three patients with normal renal function received the conventional regimen (group C). Successful eradication was confirmed by urea breath testing.

RESULTS

Eradication rates of group B (reduced amoxicillin-regimen) were 84.2% in intention-to-treat analysis and 88.9% in per-protocol analysis, which were similar with group A (77.8 and 77.8%) and group C (74.6 and 81.0%). However, the incidence of adverse events in group A was significantly higher than that in group C (22.2 vs. 5.1%, p = 0.027).

CONCLUSIONS

In H. pylori-positive hemodialysis patients, amoxicillin at 250 mg b.i.d. may be an appropriate scheme for eradication with equivalent effects to the conventional therapy and safety effects for adverse events.

Nutrition status and Helicobacter pylori infection in patients receiving hemodialysis

Chronic kidney disease (CKD) patients receiving hemodialysis (HD) often develop gastrointestinal abnormalities over their long treatment period. In general, prognosis in such patients is poor due to the development of protein-energy wasting (PEW). Therefore, it is important to clarify the etiology of PEW and to establish better strategies to deal with this condition. Chronic Helicobacter pylori (H. pylori) infection in the gastric mucosa has a close association with not only the development of peptic ulcer disease and gastric cancer, but is also associated with abnormal plasma and gastric mucosal ghrelin levels that are seen in malnutrition. It is unclear whether H. pylori infection of the gastric mucosa is directly associated with prognosis in HD patients by affecting ghrelin levels. Recent studies show that the prevalence of H. pylori infection in HD patients is significantly lower than in subjects with normal renal function. In the natural history of H. pylori infection in HD patients, the prevalence of infection decreases as the length of time on HD increases. The severity of gastric mucosal atrophy has been suggested as the major determinant of ghrelin levels in these patients, and eradication therapy of H. pylori improves nutritional status by increasing serum cholinesterase and cholesterol levels, especially in patients with mild-to-moderate gastric mucosal atrophy. Prompt H. pylori eradication to inhibit the progress of gastric atrophy may be required to prevent this decrease in ghrelin levels and subsequent PEW and improve the prognosis of HD patients by improving their nutritional status.

Natural Course of Helicobacter pylori Infection in Japanese Hemodialysis Patients

INTRODUCTION

Helicobacter pylori (H. pylori) infection is one of the major risk factors for gastrointestinal morbidity in hemodialysis patients. Primary end point is to investigate H. pylori infection rate in hemodialysis patients. As secondary end point, we clarified whether pepsinogen (PG) level was related with H. pylori infection status in hemodialysis patients.

METHODS

Serum levels of PG I, II, and anti-H. pylori IgG antibody were assessed in 500 Japanese hemodialysis patients.

RESULTS

H. pylori infection rate was 15.0% (75/500; 95% CI 12.0-18.4). The duration of hemodialysis in H. pylori-positives was 4.6 ± 3.8 years, which was significantly shorter than in H. pylori-negatives (7.3 ± 6.9, p = 0.001). PG I levels positively correlated with the PG II level and PG I/II ratio (|R| = 0.661, p < 0.001, and |R| = 0.544, p <0.001, respectively). Using a cutoff value of 7.75, the sensitivity and specificity of PG I/II ratio for predicting H. pylori-negatives were 86.3 and 87.8%, respectively (area under the curve 0.930).

CONCLUSIONS

In hemodialysis patients, infection rate with H. pylori was <20%, with lower rates in patients receiving hemodialysis for longer terms. A PG I/II ratio with a cutoff value of 7.75 may be useful for screening for H. pylori status.

Helicobacter pylori and corpus gastric pathology are associated with lower serum ghrelin

AIM

To evaluate the association of Helicobacter pylori (H. pylori), cagA genotype, and type of gastric pathology with ghrelin, leptin and nutritional status.

METHODS

Fasted dyspeptic adults (18-70 years) referred for an upper digestive endoscopy were enrolled in this cross-sectional study. Height and weight were assessed for body mass index (BMI) calculation. A sociodemographic survey was administered and nutrient intake was evaluated with 24 h dietary recalls. Serum total ghrelin and leptin levels were analyzed by enzyme-linked immunosorbent assay. ¹³C-Urea Breath Test was performed and four gastric biopsies were obtained during endoscopy for histopathology and H. pylori DNA amplification and genotyping. Data analysis was performed using χ², Mann-Whitney U, Kruskal-Wallis tests, Spearman’s correlation and linear regression.

RESULTS

One hundred and sixty-three patients (40.8 ± 14.0 years), 98/65 females/males, were included. Overall, persistent H. pylori prevalence was 53.4% (95%CI: 45.7%-65.8%). Neither nutrient intake nor BMI differed significantly between H. pylori positive and negative groups. Serum ghrelin was significantly lower in infected patients [median 311.0 pg/mL (IQR 230.0-385.5)] than in uninfected ones [median 355.0 pg/mL (IQR 253.8-547.8)] (P = 0.025), even after adjusting for BMI and gender (P = 0.03). Ghrelin levels tended to be lower in patients carrying cagA positive strains both in the antrum and the corpus; however, differences with those carrying cagA negative strains did not reach statistical significance (P = 0.50 and P = 0.49, respectively). In addition, the type and severity of gastric pathology in the corpus was associated with lower serum ghrelin (P = 0.04), independently of H. pylori status. Conversely, leptin levels did not differ significantly between infected and uninfected patients [median 1.84 ng/mL (0.80-4.85) vs 1.84 ng/mL (0.50-5.09), (P = 0.51)].

CONCLUSION

H. pylori infection and severity of gastric corpus pathology are associated with lower serum ghrelin. Further studies could confirm a lower ghrelin prevalence in cagA-positive patients.

Clinical validation of the nursing diagnosis of ineffective protection in haemodialysis patients

AIMS AND OBJECTIVES

To evaluate the clinical validity of indicators of the nursing diagnosis of "ineffective protection" in haemodialysis patients.

BACKGROUND

Haemodialysis patients have reduced protection. Studies on the nursing diagnosis of "ineffective protection" are scarce in the literature. The use of indicators to diagnose "ineffective protection" could improve the care of haemodialysis patients. The clinical usefulness of the indicators requires clinical validation.

DESIGN

This was a diagnostic accuracy study.

METHOD

This study assessed a sample of 200 patients undergoing haemodialysis in a reference clinic for nephrology during the first half of 2015. Operational definitions were created for each clinical indicator based on concept analysis and content validation by experts for these indicators. Diagnostic accuracy measurement was performed with latent class analysis with randomised effects.

RESULTS

The clinical indicator of "fatigue" had high sensitivity (p = .999) and specificity (p = 1.000) for the identification of "ineffective protection." Additionally, "maladaptive response to stress" (p = .711) and "coagulation change" (p = .653) were sensitive indicators. The main indicators that showed high specificity were "fever" (p = .987), "increased number of hospitalisations" (p = .911), "weakness" (p = .937), "infected vascular access" (p = .962) and "vascular access dysfunction" (p = .722).

CONCLUSION

A set of nine clinical indicators of "ineffective protection" were accurate and statistically significant for haemodialysis patients. Three clinical indicators showed sensitivity, and six indicators showed specificity.

RELEVANCE TO CLINICAL PRACTICE

Accurate measures for nursing diagnoses can help nurses confirm or rule out the probability of the occurrence of "ineffective protection" in patients undergoing haemodialysis.