Antral Helicobacter pylori in patients with chronic renal failure

Acute Helicobacter pylori Infection Prevalence Among Renal Failure Patients and Its Potential Roles with Other Chronic Diseases: A Retrospective Cohort Study

Background

Helicobacter pylori (H. pylori) infection is relevant to several chronic human diseases, from digestive diseases to renal, metabolic, and cancer diseases. H. pylori infections and chronic kidney diseases are in increasing, global records; if not well controlled in a specific population, these diseases might lead to more clinical complications.

Methods

In this retrospective study, we investigated the prevalence of acute H. pylori infections among 127 dialysis patients via subjecting their serums to the enzyme-linked immunosorbent assay (ELISA) to detect the human Immunoglobulin M (IgM) against H. pylori infections. Samples were from dialysis patients in a single hemodialysis center in Medina, Saudi Arabia, from January to August 2021.

Results

Our results indicated the significant prevalence of H. pylori acute infections among 33.1% of renal failure patients recruited in this study, chi-squared: 14.559, p-value: 0.0001. In addition, no significant occurrence of acute H. pylori infection among males and females, chi-squared: 1.823, p-value: 0.177. Furthermore, the prevalence of acute H. pylori infection was not significant in different age groups of renal failure patients. Chi-squared: 6.803, p-value: 0.147, despite H. pylori-infected cases predominantly represented in patients above 51 years. Moreover, we noticed that hypertension, followed by diabetes, was the most prevalent underlying medical condition among acute infected H. pylori and renal failure patients.

Conclusion

We documented the significant prevalence of acute H. pylori infection among renal failure patients. We also highlighted and discussed the possible potential roles of H. pylori in renal failure and other chronic diseases. Routine screening and treatment for acute H. pylori infection for chronic kidney diseases, hypertension, and diabetes patients would positively reduce the bacterium’s progressive effects on them. They might even improve the control of these diseases.

Helicobacter pylori Infection in Patients with Chronic Kidney Disease: A Systematic Review and Meta-Analysis

Background/Aims

Insufficient systematic reviews were conducted in the previous meta-analyses about the prevalence of Helicobacter pylori infection in patients with chronic kidney disease (CKD). The aim of this study was to evaluate the prevalence of H. pylori infection in patients with CKD.

Methods

A systematic review of studies that evaluated the prevalence of H. pylori infection in patients with CKD compared to a control group was performed. Only studies with adult patients were included, and studies with renal transplant recipients or diabetic nephropathy patients were excluded. Random-effects model meta-analyses with sensitivity analyses and subgroup analyses were conducted to confirm the robustness of the main result. A meta-regression analysis was conducted to explore the influence of potential heterogeneity on the outcomes. The methodological quality of the included publications was evaluated using the Risk of Bias Assessment tool for Nonrandomized Studies. Publication bias was also assessed.

Results

In total, 47 studies were identified and analyzed. The total prevalence of H. pylori infection was 48.2% (1,968/4,084) in patients with CKD and 59.3% (4,097/6,908) in the control group. Pooled analysis showed a significantly lower prevalence of H. pylori infection in patients with CKD (vs control group: odds ratio, 0.64; 95% confidence interval, 0.52 to 0.79). Sensitivity analyses revealed consistent results, and meta-regression analysis showed no significant confounders. No publication bias was detected.

Conclusions

The results of this study suggest a lower prevalence of H. pylori infection in patients with CKD.

Upper gastrointestinal alterations in kidney transplant candidates

Introduction:

The incidence of gastrointestinal disorders among patients with chronic kidney disease (CKD) is high, despite the lack of a good correlation between endoscopic findings and symptoms. Many services thus perform upper gastrointestinal (UGI) endoscopy on kidney transplant candidates.

Objectives:

This study aims to describe the alterations seen on the upper endoscopies of 96 kidney-transplant candidates seen from 2014 to 2015.

Methods:

Ninety-six CKD patients underwent upper endoscopic examination as part of the preparation to receive kidney grafts. The data collected from the patients' medical records were charted on Microsoft Office Excel 2016 and presented descriptively. Mean values, medians, interquartile ranges and 95% confidence intervals of the clinic and epidemiological variables were calculated. Possible associations between endoscopic findings and infection by H. pylori were studied.

Results:

Males accounted for 54.17% of the 96 patients included in the study. Median age and time on dialysis were 50 years and 50 months, respectively. The most frequent upper endoscopy finding was enanthematous pangastritis (57.30%), followed by erosive esophagitis (30.20%). Gastric intestinal metaplasia and peptic ulcer were found in 8.33% and 7.30% of the patients, respectively. H. pylori tests were positive in 49 patients, and H. pylori infection was correlated only with non-erosive esophagitis (P = 0.046).

Conclusion:

Abnormal upper endoscopy findings were detected in all studied patients. This study suggested that upper endoscopy is a valid procedure for kidney transplant candidates. However, prospective studies are needed to shed more light on this matter.

Association of Helicobacter pylori with Chronic Kidney Diseases: A Meta-Analysis

BACKGROUND/OBJECTIVES

The reported risk of chronic kidney disease (CKD) in patients with Helicobacter pylori infection is conflicting. This meta-analysis was conducted to summarize all available data and to estimate the prevalence and association between H. pylori and kidney disease and CKD.

METHODS

Comprehensive literature review was conducted using MEDLINE and EMBASE database through October 2016 to identify studies that reported the prevalence or the association between H. pylori infection and non-dialysis-dependent kidney diseases or CKD. Effect estimates from the individual study were extracted and combined using random-effect, generic inverse variance method of DerSimonian and Laird.

RESULTS

Of 4546 studies, nine cross-sectional studies met the eligibility criteria and were included in the meta-analysis. The estimated prevalence of H. pylori infection among subjects with kidney disease was 53% (95% CI 45-61%). The pooled OR of H. pylori in patients with non-dialysis-dependent kidney diseases was 1.20 (95% CI 0.73-1.97) when compared with the patients without kidney diseases. The meta-analysis was then limited to only studies evaluating the risk of H. pylori in CKD; the pooled OR of H. pylori in patients with CKD was 1.00 (95% CI 0.58-1.71).

CONCLUSIONS

The estimated prevalence of H. pylori in patients with non-dialysis-dependent kidney diseases is 53%. This study does not support the association between H. pylori infection and non-dialysis-dependent kidney diseases nor CKD.

Association between Helicobacter pylori infection and the subsequent risk of end-stage renal disease: a nationwide population-based cohort study

BACKGROUND & AIMS

The association between Helicobacter pylori infection and end-stage renal disease (ESRD) events remains unknown. We assessed the relationship between H. pylori infection requiring hospital admission and the subsequent risks of ESRD.

METHODS

This was a retrospective cohort study in which data from the National Health Insurance system of Taiwan was used. The H. pylori-infected cohort comprised 20,068 patients. Each participant was frequency-matched by age and sex with 4 individuals from the general population without H. pylori-infected. Cox proportional hazards regression analysis was used to estimate the influence of H. pylori infection on the risk of ESRD.

RESULTS

The overall incidence of ESRD was 3.72 times greater in the H. pylori-infected cohort than in the non-infected cohort (11.1 vs. 2.96 per 1000 person-years), with an adjusted HR of 2.58 [95% confidence interval (CI)=2.33-2.86]. The risk of ESRD markedly increased in patients with H. pylori infection combined with at least one of the following concomitant comorbidities: hypertension, diabetes, hyperlipidaemia and coronary artery disease.

CONCLUSIONS

This is currently the largest nation-based study in which the risk of ESRD in H. pylori-infected patients was examined. H. pylori infection was associated with a subsequent risk of ESRD. H. pylori-infected patients with concomitant chronic kidney disease (CKD) or cardiovascular disease (CVD) risk factors were at higher risk of ESRD than were those who had a single CKD or CVD risk factor.

Different peptic ulcer bleeding risk in chronic kidney disease and end-stage renal disease patients receiving different dialysis

BACKGROUND

End stage renal disease (ESRD) patients receiving hemodialysis (HD) have a higher risk of peptic ulcer bleeding (PUB).

AIMS

Whether ESRD patients receiving peritoneal dialysis (PD) also carries a higher risk of PUB has not been studied.

METHODS

This was a cohort study using Taiwan's National Health Insurance research database, whereby 11,408 patients, including 2,239 PD, 2,328 HD, 2,267 chronic kidney disease (CKD) and 4,574 controls with age-sex matching were recruited. The log-rank test was used to analyze differences in accumulated PUB-free survival rates between groups. Cox proportional hazard regression was performed to evaluate independent risk factors for PUB in all the enrollees.

RESULTS

During the 7-year follow-up, PD and CKD patients had a significantly higher rate of PUB than matched controls. The risk of PUB between PD and CKD was not significantly different. Moreover, patients receiving HD carried a higher risk of PUB than those receiving PD, with CKD and controls (p all <0.05, by log-rank test). Cox proportional hazard regression analysis showed that CKD (HR 3.99, 95 % CI 2.24-7.13), PD (HR 3.71, 95 % CI 2.00-6.87) and HD (HR 11.96, 95 % CI 7.04-20.31) were independently associated with an increased risk of PUB. Being elderly, male, having hypertension, diabetes, cirrhosis, and nonsteroidal anti-inflammatory drugs and steroid use were other independent risk factors of PUB in all enrollees.

CONCLUSIONS

Patients with CKD and ESRD receiving PD or HD carried a higher risk for PUB. They should be screened for risk factors for PUB and receive some protective measures to prevent PUB.

Helicobacter pylori Infection in Dialysis Patients: A Meta-Analysis

Background. Infection with Helicobacter pylori contributes to the etiopathogenesis of various extragastrointestinal conditions, yet its etiological association with either symptomatic or asymptomatic dialysis patients remains inconclusive. Methods. Two researchers working independently conducted a literature search of the online databases PubMed, EMBase, ScienceDirect, and Cochrane Central Register of Controlled Trials to identify relevant articles to the end of 2012. Case-control and cross-sectional studies that met the inclusion criteria were included. Results. Fifteen studies involving 1237 dialysis patients and 1568 controls with normal renal function were included. Compared with normal controls, dialysis patients overall were associated with a relatively lower risk of H. pylori infection though not statistically significant. A significant inverse association was found between H. pylori prevalence and duration of treatments in those who were dialyzed >4 years (odds ratio 0.28; 95% confidence interval 0.22–0.36, P < 0.00001). No relationship between H. pylori status and duration of dialysis was observed in CRF patients. There were no significant differences in endoscopic features between patients and controls. Conclusions. Our meta-analysis found no evidence of a significant association between infection with H. pylori and dialysis overall, whereas long-term treatments of more than four years had a significant protective effect.

Incidence of bleeding from gastroduodenal ulcers in patients with end-stage renal disease receiving hemodialysis

BACKGROUND

Few large population-based studies have compared the incidence of bleeding of gastroduodenal ulcers between patients with and without end-stage renal disease. We investigated the association between ulcer bleeding and end-stage renal disease in patients receiving hemodialysis, and we sought to identify risk factors for ulcer bleeding.

METHODS

We performed a nationwide seven-year population study using data from the National Health Insurance Research Database in Taiwan. We identified 36 474 patients with end-stage renal disease who were receiving hemodialysis, 6320 patients with chronic kidney disease and 36 034 controls matched for age, sex and medication use. We performed log-rank testing to analyze differences in survival time without ulcer bleeding among the three groups. We performed Cox proportional hazard regressions to evaluate the risk factors for ulcer bleeding among the three groups and to identify risk factors in patients receiving hemodialysis.

RESULTS

Patients receiving hemodialysis and those with chronic kidney disease had a significantly higher incidence of ulcer bleeding than controls had (p<0.001). Hemodialysis (hazard ratio [HR] 5.24, 95% confidence interval [CI] 4.67-5.86) and chronic kidney disease (HR 1.95, 95% CI 1.62-2.35) were independently associated with an increased risk of ulcer bleeding. Diabetes mellitus, coronary artery disease, cirrhosis and use of nonsteroidal anti-inflammatory drugs were risk factors for ulcer bleeding in patients with end-stage renal disease who were receiving hemodialysis

INTERPRETATION

Patients with end-stage renal disease who are receiving hemodialysis had a high risk of ulcer bleeding. Diabetes mellitus, coronary artery disease, cirrhosis and the use of nonsteroidal anti-inflammatory drugs were important risk factors for ulcer bleeding in these patients.

Incidence of bleeding from gastroduodenal ulcers in patients with end-stage renal disease receiving hemodialysis

BACKGROUND

Few large population-based studies have compared the incidence of bleeding of gastroduodenal ulcers between patients with and without end-stage renal disease. We investigated the association between ulcer bleeding and end-stage renal disease in patients receiving hemodialysis, and we sought to identify risk factors for ulcer bleeding.

METHODS

We performed a nationwide seven-year population study using data from the National Health Insurance Research Database in Taiwan. We identified 36 474 patients with end-stage renal disease who were receiving hemodialysis, 6320 patients with chronic kidney disease and 36 034 controls matched for age, sex and medication use. We performed log-rank testing to analyze differences in survival time without ulcer bleeding among the three groups. We performed Cox proportional hazard regressions to evaluate the risk factors for ulcer bleeding among the three groups and to identify risk factors in patients receiving hemodialysis.

RESULTS

Patients receiving hemodialysis and those with chronic kidney disease had a significantly higher incidence of ulcer bleeding than controls had (p<0.001). Hemodialysis (hazard ratio [HR] 5.24, 95% confidence interval [CI] 4.67-5.86) and chronic kidney disease (HR 1.95, 95% CI 1.62-2.35) were independently associated with an increased risk of ulcer bleeding. Diabetes mellitus, coronary artery disease, cirrhosis and use of nonsteroidal anti-inflammatory drugs were risk factors for ulcer bleeding in patients with end-stage renal disease who were receiving hemodialysis

INTERPRETATION

Patients with end-stage renal disease who are receiving hemodialysis had a high risk of ulcer bleeding. Diabetes mellitus, coronary artery disease, cirrhosis and the use of nonsteroidal anti-inflammatory drugs were important risk factors for ulcer bleeding in these patients.

Review of Helicobacter pylori infection and chronic renal failure

Chronic renal failure patients receiving hemodialysis and continuous ambulatory peritoneal dialysis often encounter gastrointestinal troubles over their long treatment period. Helicobacter pylori infection has close association with development of peptic ulcer, gastric cancer and gastric lymphoma, and is thought to be one of the major risk factors for gastrointestinal troubles in dialysis patients. However, it is unclear whether H. pylori infection is directly associated with progression of renal dysfunction and prognosis of chronic renal failure patients. Recent consensus shows that the prevalence of H. pylori infection in chronic renal failure patients is significantly lower than in subjects with normal renal function. In the natural history of H. pylori infection in hemodialysis patients, the prevalence of infection decreases as dialysis periods progressed, in particular within the first four years after the start of treatment. However, the chance of natural eradication becomes rare for patients receiving dialysis treatment for a long time. Moreover, chronic renal failure patients with H. pylori infection have a higher incidence of gastroduodenal diseases, and therefore, are recommended to receive eradication therapies, especially for those receiving treatment for a long time and with higher risks of complication. Intensive endoscopic check-ups for the prevention of gastrointestinal events and the discovery of peptic ulcer and neoplastic diseases at an early phase may be required.

Prevalence of Helicobacter pylori infection in long-term hemodialysis patients

Patients on hemodialysis often have gastrointestinal complications; however, it is unclear if Helicobacter pylori infection is present in these patients. Here we determined the prevalence of H. pylori infection in 539 Japanese hemodialysis patients by measuring serum anti-H. pylori IgG antibodies. Endoscopy was performed on 299 of these patients and the results were compared to 400 patients with normal renal function who had also undergone endoscopy and sero-testing. A second cohort of 478 dialysis patients, within the original group, was checked serologically for H. pylori infection three times over a four-year observation period. The prevalence of infection in these patients was significantly lower than in those patients with normal renal function, irrespective of the clinical outcomes. The prevalence of H. pylori infection significantly decreased as the duration of dialysis increased, particularly within the first four years following initiation of dialysis. About one-third of patients on dialysis for less than four years became serologically negative for H. pylori infection within this observation period. Our study suggests that although long-term dialysis patients have low prevalence of H. pylori, they still have significant gastroduodenal diseases, such as peptic ulcers, that require endoscopic follow-up.

Prevalence of gastroesophageal reflux disease and its association with Helicobacter pylori infection in chronic renal failure patients and in renal transplant recipients

BACKGROUND/AIMS

The prevalence of gastroesophageal reflux disease (GERD) in chronic renal failure patients and in renal transplant recipients (RTR) has been a subject of discussion in the last few years. Our aims are to clarify this association and its relation to Helicobacter pylori infection, and also to identify possible pathogenic factors in the development of this disease in both groups.

METHODS

The study involved 40 end-stage renal disease (ESRD) patients with upper gastrointestinal (GI) symptoms (group I), 36 patients who had undergone kidney transplantation and had similar symptoms (group II), and 44 age- and sex-matched controls with the same upper GI symptoms (group III). All patients were subjected to esophagogastroduodenoscopy, and biopsies were obtained from the antrum for histological evaluation and identification of H. pylori.

RESULTS

The prevalence of GERD in the first two groups was similar (77.5 vs. 75.0%, P = 0.412), while it was significantly lower in the control group (38.6%, P < 0.01). H. pylori infection was present in 40.0, 36.1 (P > 0.05) and 75% (P < 0.01 and < 0.001) of the patients in groups I, II, and III, respectively. Multivariate logistic regression analysis in groups I and II showed that high serum creatinine (Odds ratio [OR] = 6.78, 95% Confidence Interval (CI) = 1.12-45.82), immunosuppressive therapy (OR = 5.78, 95% CI = 1.01-32.5), and absence of H. pylori infection (OR = 3.58, 94% CI = 1.11-18.6) were significantly associated with GERD. The duration of ESRD correlated significantly with the prevalence of GERD in group I.

CONCLUSIONS

This study showed a similar prevalence of H. pylori infection and GERD in ESRD and RTR patients. GERD prevalence was higher in these two groups than in the controls. Renal transplantation, chronic renal disease, immunosuppressive therapy, and the absence of H. pylori infection seem to be risk factors for the development of GERD.

Seroprevalence of Helicobacter pylori in Chinese patients on continuous ambulatory peritoneal dialysis

BACKGROUNDS AND AIMS

There is relatively little data on the seroprevalence of Helicobacter pylori in patients undergoing continuous ambulatory peritoneal dialysis (CAPD). This study aims at establishing the seroprevalence of and the factors associated with H. pylori infection in Chinese CAPD patients.

METHODS

All CAPD patients from a single dialysis centre were invited to participate in the study. Diagnosis of H. pylori infection was made serologically by the pylori DTect ELISA method. Dyspeptic symptoms were assessed by the Hong Kong Index of Dyspepsia (HKID) Questionnaire. Demographic, clinical and laboratory parameters were correlated with the H. pylori serology results.

RESULTS

One hundred and thirty-six Chinese CAPD patients were included in the study. The mean age of the patients was 61.8 +/- 12.5 years with a male to female ratio of 1:1.4. The mean duration of CAPD was 54 +/- 42 months. Thirty-five patients (26%) have positive serology against H. pylori. Nineteen patients had a HKID score of >16. There was no association between H. pylori seropositivity and dyspeptic symptoms (P = 0.62). Patients who were seropositive for H. pylori were significantly older (64.9 +/- 9.5 years vs 60.7 +/- 13.2 years, P < 0.05) and had lower KT/V-values than patients who were seronegative for H. pylori (1.88 +/- 0.3 vs 2.03 +/- 0.3, P < 0.05). Patients with positive or negative H. pylori serological status did not differ in terms of demographic parameters (e.g. sex, duration of CAPD), clinical factors (e.g. bodyweight, body mass index, hepatitis status, use of H(2) antagonists or proton pump inhibitors) and laboratory data (e.g. haemoglobin, serum urea, creatinine, albumin and parathyroid hormone levels).

CONCLUSIONS

The seroprevalence of H. pylori infection among Chinese CAPD patients is 26%. Helicobacter pylori seropositivity is not associated with dyspepsia. Older age and lower KT/V-values appear to be associated with the development of H. pylori seropositivity in our dialysis population.

Critical care issues in the patient with chronic renal failure

The metabolic abnormalities associated with chronic renal failure and complications of the dialysis procedure present unique challenges in critical care medicine. Understanding how renal failure impacts the development and management of cardiovascular disease, bleeding tendencies, infection, and malnutrition is necessary to provide optimal care for these patients. The recognition of ESRD as a state of chronic inflammation and increased oxidative stress ultimately should lead to more effective treatment approaches for several of the comorbid conditions common in this patient population.

Epidemiology of Helicobacter pylori in chronic haemodialysis patients using the new RIBA H. pylori SIA

BACKGROUND

There are few data concerning the epidemiology of H. pylori in patients on chronic haemodialysis (HD) treatment. These surveys concerned small populations and were made with ELISA technique. However, ELISA-based assays do not differentiate between strains of H. pylori that are associated with ulcers. Recent literature reports that formation of ulcers correlates strongly with the expression of cytotoxin-associated protein (CagA) and vacuolating cytotoxin (VacA) of H. pylori.

METHODS

A novel serological test (RIBA H. pylori strip immunoblot assay (SIA)) has been recently introduced, it uses the H. pylori lysate (Lys) along with two additional purified recombinant antigens derived from CagA and VacA of H. pylori.

AIM

To study the epidemiology of H. pylori using RIBA H. pylori SIA among chronic HD patients and blood donors as a control group. In addition, the activity of H. pylori was analysed by immunoblot technique in a group of patients with documented ulcers and normal renal function.

RESULTS

The prevalence of antibody towards H. pylori among HD patients, blood donors, and patients with documented ulcers was 56% (127/228), 53% (84/158), and 100%, (21/21) respectively; the difference was significant (P=0.0001). The frequency of anti-H. pylori-positive individuals was significantly higher in patients with documented ulcers than HD patients and blood donors, 21/21 (100%) vs 211/386 (55%), P=0.0001. The frequency of antibody to H. pylori in the HD population was significantly associated with race (P= 0.005); no relationship between anti-H. pylori antibody and numerous demographic, biochemical, and clinical features of patients was seen. The frequency of antibodies against virulent strains of H. pylori in HD patients and blood donors with H. pylori was 60% (76/127) and 61% (51/84) respectively; it was 86% (18/21) among individuals with documented ulcers. No significant difference among these three groups occurred.

CONCLUSIONS

The frequency of antibody towards H. pylori by RIBA H. pylori SIA was high both in HD patients and blood donors; patients with documented ulcers and normal renal function had significantly higher frequency of anti-H. pylori antibody. The anti-H. pylori antibody rate among HD patients was strongly associated with race. The prevalence of antibody against virulent strains of H. pylori did not change among HD patients and control groups. Studies in large cohorts of HD patients with documented peptic ulcer disease are in progress.

Peptic ulcer and gastritis in uraemia, with particular reference to the effect of Helicobacter pylori infection

AIMS

To determine: (i) the prevalence of histological gastritis and peptic ulcer; and (ii) the clinical features of peptic ulcer, in patients with end-stage renal failure.

METHODS

Upper endoscopy was performed by a single observer in 268 patients with end-stage renal failure over a 6-year period. Gastric histology and Helicobacter pylori status were studied in 40 consecutive subjects in whom there were no contraindications for gastric biopsy and who had not used antibacterial drugs in the preceding 4 weeks. As there are only limited data for healthy volunteers in Singapore, 33 age-, sex- and race-matched patients with functional dyspepsia from an earlier drug trial and 18 healthy volunteers who were not age-matched were used as controls. The clinical features of 43 consecutive uraemic patients with peptic ulcer were compared with those of 118 consecutive non-uraemic peptic ulcer patients seen by the same author.

RESULTS

Among uraemic patients, histological gastritis was less common, compared with healthy volunteers and functional dyspepsia patients. Helicobacter pylori infection as assessed by histology was also less common among uraemic patients compared with functional dyspepsia patients, but the difference was not statistically significant on serological assessment. Uraemic patients with ulcer had an equal sex ratio, in contrast to a male preponderance among peptic ulcer patients with normal renal function. Uraemic patients with ulcer were more likely to be pain-free, to present with haemorrhage, to have multiple ulcers and postbulbar duodenal ulcers, but were less likely to have H. pylori infection. Among uraemic subjects, the prevalence of H. pylori infection was similar whether or not peptic ulcer was present.

CONCLUSIONS

The prevalence of histological gastritis was lower in uraemic patients when compared with patients with functional dyspepsia and healthy volunteers. Peptic ulcers in uraemic subjects have different clinical characteristics from peptic ulcer in non-uraemic subjects.

Decreased sensitivity of the ultrarapid urease test for diagnosing Helicobacter pylori in patients with chronic renal failure

Fifty patients with chronic renal failure and 50 asymptomatic healthy volunteers were studied to determine the prevalence of Helicobacter pylori in the two groups and to compare the results of ultrarapid urease test (URUT) and gastric histology for detecting H. pylori infection. Four gastric antral biopsy specimens were taken. Two specimens were used for the URUT and two were processed routinely. Sections were stained with H&E and Loeffler's methylene blue. Histological examination showed presence of H. pylori in 56% of patients with chronic renal failure (CRF) and in 78% of the controls. The difference was statistically significant (p < 0.05). The URUT was positive in only 16% of patients with CRF compared to 74% in the controls (p < 0.0001). The sensitivity and overall diagnostic accuracy of the URUT to diagnose H. pylori infection were 94.8 and 96%, respectively, in controls but were only 29 and 60%, respectively, in patients with CRF. It is concluded that the prevalence of H. pylori is significantly less in patients with CRF and that the URUT is less sensitive than gastric histology for diagnosing H. pylori infection in these patients.

Gastrointestinal complications of renal failure

ESRD has well-documented effects on the esophagus, stomach, duodenum, and pancreas. Unless the supply of donor kidneys increases dramatically, these complications of ESRD will continue to be an important clinical issue for gastroenterologists given the large percentage of patients with symptoms. Further study of uremic retention products and abnormal gastrointestinal hormone profiles on the gastrointestinal tract should help provide additional insights into this complex group of patients.

Gastrointestinal function in chronic renal failure

Feeding problems, anorexia and vomiting are common in infants and children with chronic renal failure (CRF), and play a major role in the growth failure often found in this condition. However, the gastroenterological and nutritional aspects of CRF in children have received little attention, hence therapeutic interventions are usually empirical and often ineffective. Gastritis, duodenitis and peptic ulcer are often found in adults with CRF on regular haemodialysis and following renal transplantation. Despite persistent hypergastrinaemia, gastric acid secretion is decreased rather than increased in most of these patients, and active peptic disease appears to be promoted by the removal of the acid output inhibition (neutralisation of gastric acid by ammonia) that follows active treatment. Helicobacter pylori, on the other hand, does not seem to play a significant role in the pathogenesis of peptic disease in CRF. Gastro-oesophageal reflux has been found in about 70% of infants and children with CRF suffering from vomiting and feeding problems, and thus appears to be a major problem in these patients. In a number of symptomatic patients with CRF, gastric dysrhythmias and delayed gastric emptying have also been found; hence there appears to be a complex disorder of gastrointestinal motility in CRF. Serum levels of several polypeptide hormones involved in the modulation of gastrointestinal motility [e.g. gastrin, cholecystokinin (CCK), neurotensin] and the regulation of hunger and satiety (e.g. glucagon, CCK) are significantly raised as a consequence of renal insufficiency, and can be reverted to normal by renal transplantation. Furthermore, several other humoral abnormalities (e.g. hypercalcaemia, hypokalaemia, acidosis, etc.) are not uncommon in CRF. By directly affecting the smooth muscle of the gut or stimulating particular areas within the central nervous system, all these humoral alterations may well play a major role in the gastrointestinal dysmotility, anorexia, nausea and vomiting in patients with CRF. Specific pharmacological and nutritional interventions should thus be considered for the treatment of vomiting and feeding problems in CRF.

Significantly lower prevalence of Helicobacter pylori in uremic patients than in patients with normal renal function

The objective of the study was to evaluate the prevalence of Helicobacter pylori in patients with different degrees of renal function. Two hundred and twenty consecutive patients requiring gastroscopy for upper intestinal symptoms were enrolled in the study: group I (normal renal function, n = 127), group II (chronic renal failure, creatinine clearance > 5 < 90 ml/min, n = 59), and group III (hemodialysis therapy, n = 34). On endoscopy, biopsy specimens were taken for analysis of H. pylori infection by urease test and histology. The prevalence of H. pylori in patients with renal dysfunction proved to be significantly lower than that in patients with normal renal function (22.6% vs 37%, P < 0.05). The incidence of ulcer disease in patients with normal renal function was higher than that in uremic patients (14.2% vs 10.8%, not significant). These findings indicate that uremic patients seem to be partly protected against H. pylori infection.

Gastric and pancreatic functions in haemodialyzed patients

The aim of this work was to assess gastric acid secretion in relation to morphological and histological changes in the gastric mucosa as well as prevalence of Helicobacter pylori in chronically haemodialyzed uraemic patients. Exocrine pancreatic functions after secretin-cerulein test were also studied. In haemodialyzed patients low basal gastric acid output was found, whereas peak output after pentagastrin stimulation did not differ significantly when compared to controls. Endoscopy of gastric and duodenal mucosa revealed inflammatory changes in the majority of patients, described histologically as chronic gastritis with duodenitis. Helicobacter pylori antigen was detected in the serum of 45% of uraemic patients. Serum amylase activity was elevated in haemodialyzed patients relative to controls. Although clinically asymptomatic, haemodialyzed patients exhibited various degrees of gastrointestinal mucosal abnormalities and impairment in exocrine pancreatic functions, mainly low stimulated bicarbonate and protein output as well as low electrolyte concentrations in duodenal content.

The gastrointestinal tract in uremia

Gastrointestinal mucosal abnormalities ranging from edema to ulceration occur in two thirds of patients dying of uremia. Early studies suggested that uremic patients on maintenance dialysis treatment were at increased risk of peptic ulceration but more recent data indicate that this is not so. Other gastrointestinal problems reported for uremic subjects on maintenance dialysis treatment include bleeding from telangiectatic lesions, constipation, mucosal deposition of amyloid and acute pancreatitis. Nausea and vomiting are common in the uremic patient but gastric emptying studies have yielded conflicting results. Patients undergoing renal transplantation are at increased risk of development of esophagitis, complicated peptic ulcer, intestinal ulceration, and perforation as well as acute pancreatitis.

Effect of chewing Qat on mucosal histology and prevalence of Helicobacter pylori in the oesophagus, stomach and duodenum of Yemeni patients

This investigation was aimed at assessing whether the Yemeni habit of chewing Qat on a regular basis had a significant effect on the upper alimentary tract. Seventy patients with dyspepsia attending Al-Thawra Hospital in Taiz, Yemen Republic were examined by endoscopy. Biopsies were taken from the oesophagus, stomach and duodenum. The patients included 28 who gave a history of daily Qat intake, 21 with less frequent intake and 21 who took none. The only statistically significant finding associated with daily Qat intake was a higher prevalence of duodenal ulcer, particularly in females. However, a strong association was also found between heavy smoking and ulcer, with most ulcer patients who chewed Qat daily being heavy smokers. Chewing Qat was not associated with a higher prevalence of oesophageal dysplasia, making it unlikely to be the cause of the perceived high incidence of oesophageal carcinoma in Yemen. There was a high prevalence of gastric H. pylori colonization (93%) and columnar-lined lower end of oesophagus (18%), as well as low prevalence of intestinal metaplasia of stomach (4%); this was not, however, related to chewing Qat. Further epidemiological and histological studies are needed to assess the significance of these findings in relation to the incidence of oesophageal and gastric carcinoma in Yemen.

Gastric Helicobacter and upper gastrointestinal symptoms in chronic renal failure

We studied histologically antral biopsies from 89 consecutive patients with chronic renal failure for Helicobacter pylori (previously Campylobacter pylori). A dose-response gastric secretion test was also performed. The frequency of Helicobacter-positive subjects was low (15/89, 17%), corresponding to figures reported in the literature for young symptomless volunteers. Helicobacter-positive patients had significantly more frequently upper gastrointestinal symptoms than Helicobacter-negative individuals (P less than 0.05). Antral gastritis was more common in the Helicobacter-positive than in the Helicobacter-negative renal patients (P less than 0.01), but the incidence of body gastritis did not differ between them. The Helicobacter-positive patients had lower serum urea levels (P less than 0.01) and higher acid outputs (P less than 0.001) than Helicobacter-negative subjects. All patients had raised fasting serum gastrin levels, which possibly obscured the difference between Helicobacter-positive (283 pg/ml) and -negative (331 pg/ml) patients. We conclude that in chronic renal failure gastric colonization of Helicobacter pylori is not more frequent than usual. It correlates positively with antral gastritis, gastric acid output and upper gastrointestinal symptoms, but negatively with serum urea levels.