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

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.

Contemporary migration patterns in the prevalence of Helicobacter pylori infection: A systematic review

BACKGROUND

A rapid growth in the number of international migrants over the past years has occurred with most traveling to more affluent settings. As Helicobacter pylori infects over half of the adult population and its prevalence is higher in developing countries, understanding the prevalence of infection in migrants can provide insight into future trends in the burden and management of infection. We aimed to describe the prevalence of H. pylori among migrants through a systematic literature review.

METHODS

We searched PubMed^® from inception to September 2015 to identify studies reporting the prevalence of H. pylori in international migrants according to country of birth for first-generation, and country of birth and parents' nationality for successive generations. Comparable data from origin and destination populations were obtained from the same studies or, when not present, from a previous systematic review on H. pylori worldwide.

RESULTS

A total of 28 eligible studies were identified with data for 29 origin and 12 destination countries. Two studies that evaluated refugees presented prevalences of infection higher than both the origin and destination countries. Otherwise, the prevalences among migrants were generally similar or below that of the origin and higher than the destination. Second- or more generation had lower prevalences compared to first-generation migrants.

CONCLUSIONS

Our study findings are consistent with what would be expected based on the prevalence of H. pylori worldwide. The results of this review show that migrants are particularly at risk of infection and help to identify gaps in the knowledge of migrants' prevalence of infection globally.

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.

Usefulness of non-invasive tests for diagnosing Helicobacter pylori infection in patients undergoing dialysis for chronic renal failure

BACKGROUND

Helicobacter pylori infection in chronic renal failure patients has been linked to peptic ulcer and gastric neoplasia after kidney transplantation. It may also contribute to the accelerated arteriosclerosis that is usual in this population. Few data are available on the usefulness of noninvasive diagnostic tests for H. pylori infection in dialyzed patients, especially regarding the new fecal antigen detection tests. The objective of this study was to determine the efficacy of a noninvasive test for H. pylori infection in patients with chronic renal failure.

METHODS

Eighty-six patients were included in a cross-sectional study. Urea breath test, serology and three fecal tests--FemtoLab H. pylori (Connex, Germany), Premier Platinum HpSA (Meridian, USA) and Simple H. pylori (Operon SA, Spain) were performed. Helicobacter pylori status was determined by concordance of the tests. Sensitivity, specificity and positive and negative predictive values were calculated for each test.

RESULTS

Sensitivity, specificity, positive and negative predictive values were 94%, 96%, 94% and 96% for the urea breath test; 97%, 64%, 66% and 97% for serology; 86%, 100%, 100% and 91%, for FemtoLab H. pylori; 58%, 96%, 91% and 76% for Premier Platinum HpSA and 61%, 78%, 74% and 67% for Simple H. pylori.

CONCLUSIONS

The urea breath test seems to be the most reliable diagnostic method for H. pylori infection in patients with chronic renal failure. Serology has a low specificity, and the results of the fecal tests vary widely.