Urea breath test for Helicobacter pylori infection in adult dyspeptic patients: A meta-analysis of diagnostic test accuracy

BACKGROUND

Helicobacter pylori (H. pylori) infection has been well-established as a significant risk factor for several gastrointestinal disorders. The urea breath test (UBT) has emerged as a leading non-invasive method for detecting H. pylori. Despite numerous studies confirming its substantial accuracy, the reliability of UBT results is often compromised by inherent limitations. These findings underscore the need for a rigorous statistical synthesis to clarify and reconcile the diagnostic accuracy of the UBT for the diagnosis of H. pylori infection.

AIM

To determine and compare the diagnostic accuracy of 13C-UBT and 14C-UBT for H. pylori infection in adult patients with dyspepsia.

METHODS

We conducted an independent search of the PubMed/MEDLINE, EMBASE, and Cochrane Central databases until April 2022. Our search included diagnostic accuracy studies that evaluated at least one of the index tests (13C-UBT or 14C-UBT) against a reference standard. We used the QUADAS-2 tool to assess the methodological quality of the studies. We utilized the bivariate random-effects model to calculate sensitivity, specificity, positive and negative test likelihood ratios (LR+ and LR-), as well as the diagnostic odds ratio (DOR), and their 95% confidence intervals. We conducted subgroup analyses based on urea dosing, time after urea administration, and assessment technique. To investigate a possible threshold effect, we conducted Spearman correlation analysis, and we generated summary receiver operating characteristic (SROC) curves to assess heterogeneity. Finally, we visually inspected a funnel plot and used Egger's test to evaluate publication bias.

RESULTS

The titles and abstracts of 4621 studies were screened; 79 articles were retrieved and selected for full-text reading. Finally, 60 studies were included in the diagnostic test accuracy meta-analysis. Our analysis demonstrates superior diagnostic accuracy of 13C-UBT over 14C-UBT, indicated by higher sensitivity (96.60% vs 96.15%), specificity (96.93% vs 89.84%), likelihood ratios (LR+ 22.00 vs 10.10; LR- 0.05 vs 0.06), and area under the curve (AUC; 0.979 vs 0.968). Notably, 13C-UBT's DOR (586.47) significantly outperforms 14C-UBT (DOR 226.50), making it the preferred diagnostic tool for dyspeptic individuals with H. pylori infection. Correlation analysis revealed no threshold effect (13C-UBT: r = 0.48; 14C-UBT: r = -0.01), and SROC curves showed consistent accuracy. Both 13C-UBT and 14C-UBT showed high AUC values (13C-UBT 0.979; 14C-UBT 0.968) near 1.00, reinforcing their excellent accuracy and endorsing both as reliable diagnostic tools in clinical practice.

CONCLUSION

In summary, our study has demonstrated that 13C-UBT has been found to outperform the 14C-UBT, making it the preferred diagnostic approach. Additionally, our results emphasize the significance of carefully considering urea dosage, assessment timing, and measurement techniques for both tests to enhance diagnostic precision. Nevertheless, it is crucial for researchers and clinicians to evaluate the strengths and limitations of our findings before implementing them in practice.

Correction to “Performance of a serological IgM and IgG qualitative test for COVID-19 diagnosis: An experimental study in Brazil”

Correction to “Freire de Melo F, Martins Oliveira Diniz L, Nélio Januário J, Fernando Gonçalves Ferreira J, Dórea RSDM, de Brito BB, Marques HS, Lemos FFB, Silva Luz M, Rocha Pinheiro SL, de Magalhães Queiroz DM. Performance of a serological IgM and IgG qualitative test for COVID-19 diagnosis: An experimental study in Brazil. World J Exp Med 2022; 12(5): 100-103 [PMID: 36196438 DOI: 10.5493/wjem.v12.i5.100]”. In this article, we identified an issue with the “Acknowledgments” section. Here, we then provide a recognition section for our supporting institutions.

Epidemiological and clinical characteristics of COVID-19 in a Brazilian public hospital

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic has become a major health concern worldwide. In that context, the understanding of epidemiological and clinical features associated with the disease and its severity is crucial for the establishment of strategies aimed at disease control and remedy.

AIM

To describe epidemiological features, signs, symptoms, and laboratory findings among severely ill COVID-19 patients from an intensive care unit in northeastern Brazil as well as to evaluate predictor factors for disease outcomes.

METHODS

This is a prospective single-center study that evaluated 115 patients admitted to the intensive care unit in a northeastern Brazilian hospital.

RESULTS

The patients had a median age of 65.60 ± 15.78 years. Dyspnea was the most frequent symptom, affecting 73.9% of the patients, followed by cough (54.7%). Fever was reported in approximately one-third of patients and myalgia in 20.8% of the patients. At least two comorbidities were found in 41.7% of the patients, and hypertension was the most prevalent (57.3%). In addition, having two or more comorbidities was a predictor of mortality, and lower platelet count was positively associated with death. Nausea and vomiting were two symptoms that were predictors of death, and the presence of a cough was a protective factor.

CONCLUSION

This is the first report of a negative correlation between cough and death in severely ill severe acute respiratory syndrome coronavirus 2-infected individuals. The associations between comorbidities, advanced age, and low platelet count and the outcomes of the infection were similar to the results of previous studies, highlighting the relevance of these features.

Performance of a serological IgM and IgG qualitative test for COVID-19 diagnosis: An experimental study in Brazil

Qualitative antibody tests are an easy, point-of-care diagnostic method that is useful in diagnosing coronavirus disease 2019, especially in situations where reverse transcription-polymerase chain reaction is negative. However, some factors are able to affect its sensitivity and accuracy, which may contribute to these tests not being used as a first-line diagnostic tool.

COVID-19 and dengue coinfection in Brazil

The case we present here is a man who lives in a dengue-endemic area. Initially, the patient was diagnosed with dengue fever by clinical evaluation and laboratorial confirmation. Subsequently, he presented respiratory symptoms, and a concomitant severe acute respiratory syndrome coronavirus 2 infection was confirmed. He was hospitalized for 17 d and had a satisfactory recovery.

Treatment of Helicobacter pylori infection in children: A systematic review

BACKGROUND

Helicobacter pylori (H. pylori) infection is predominantly acquired in childhood. When indicated, the most accepted treatment for H. pylori eradication in this age group is first-line triple therapy. However, the increasing resistance to clarithromycin and nitroimidazoles has been associated with treatment failure, and thus, alternative treatment regimens have been proposed.

AIM

To perform a systematic review of randomized controlled trials on treatment regimens for H. pylori infection in children.

METHODS

We surveyed relevant articles published in English from 2010 to April 2020 in the PubMed and MEDLINE databases. Keywords included “Helicobacter pylori”/”children or childhood”/”treatment or eradication.” The risk of bias was evaluated according to the Cochrane Handbook of Systematic Reviews for Interventions.

RESULTS

Among the 1144 records identified through the database, 20 articles were selected. Four studies compared the eradication rates of H. pylori infection between standard triple therapies, changing only the main antibiotic used. Seven studies evaluated the effectiveness of standard triple therapy with the addition of probiotics. One study investigated the relationship between the effectiveness in the eradication rates of standard triple therapy and vitamin E levels. Six studies analyzed the eradication rates of sequential therapy.

CONCLUSION

The findings suggest that although standard triple therapy is the most recommended regimen for children by the current guidelines, other therapeutic schemes have shown promising results and may also be recommended for clinical practice in the future.

Helicobacter pylori infection: Beyond gastric manifestations

Helicobacter pylori (H. pylori) is a bacterium that infects more than a half of world’s population. Although it is mainly related to the development of gastroduodenal diseases, several studies have shown that such infection may also influence the development and severity of various extragastric diseases. According to the current evidence, whereas this bacterium is a risk factor for some of these manifestations, it might play a protective role in other pathological conditions. In that context, when considered the gastrointestinal tract, H. pylori positivity have been related to Inflammatory Bowel Disease, Gastroesophageal Reflux Disease, Non-Alcoholic Fatty Liver Disease, Hepatic Carcinoma, Cholelithiasis, and Cholecystitis. Moreover, lower serum levels of iron and vitamin B12 have been found in patients with H. pylori infection, leading to the emergence of anemias in a portion of them. With regards to neurological manifestations, a growing number of studies have associated that bacterium with multiple sclerosis, Alzheimer’s disease, Parkinson’s disease, and Guillain-Barré syndrome. Interestingly, the risk of developing cardiovascular disorders, such as atherosclerosis, is also influenced by the infection. Besides that, the H. pylori-associated inflammation may also lead to increased insulin resistance, leading to a higher risk of diabetes mellitus among infected individuals. Finally, the occurrence of dermatological and ophthalmic disorders have also been related to that microorganism. In this sense, this minireview aims to gather the main studies associating H. pylori infection with extragastric conditions, and also to explore the main mechanisms that may explain the role of H. pylori in those diseases.

Interleukin-6-174G/C polymorphism is associated with a decreased risk of type 2 diabetes in patients with chronic hepatitis C virus

BACKGROUND

Chronic hepatitis C (CHC) is associated with type 2 diabetes mellitus. Although the pathogenesis remains to be elucidated, a growing evidence has suggested a role of pro-inflammatory immune response. Increased serum concentrations of Interleukin 6 (IL-6) have been associated with insulin resistance, type 2 diabetes mellitus as well as advanced forms of liver disease in chronic hepatitis C infection.

AIM

To investigate the frequency of IL-6-174G/C (rs1800795) single nucleotide polymorphism (SNP) in CHC patients and in healthy subjects of the same ethnicity. Associations between type 2 diabetes mellitus (dependent variable) and demographic, clinical, nutritional, virological and, IL-6 genotyping data were also investigated in CHC patients.

METHODS

Two hundred and forty-five patients with CHC and 179 healthy control subjects (blood donors) were prospectively included. Type 2 diabetes mellitus was diagnosed according to the criteria of the American Diabetes Association. Clinical, biochemical, histological and radiological methods were used for the diagnosis of the liver disease. IL-6 polymorphism was evaluated by Taqman SNP genotyping assay. The data were analysed by logistic regression models.

RESULTS

Type 2 diabetes mellitus, blood hypertension and liver cirrhosis were observed in 20.8% (51/245), 40.0% (98/245) and 38.4% (94/245) of the patients, respectively. The frequency of the studied IL-6 SNP did not differ between the CHC patients and controls (P = 0.81) and all alleles were in Hardy-Weinberg equilibrium (P = 0.38). In the multivariate analysis, type 2 diabetes mellitus was inversely associated with GC and CC genotypes of IL-6-174 (OR = 0.42; 95%CI = 0.22-0.78; P = 0.006) and positively associated with blood hypertension (OR = 5.56; 95%CI = 2.79-11.09; P < 0.001).

CONCLUSION

This study was the first to show that GC and CC genotypes of IL-6-174 SNP are associated with a decreased risk of type 2 diabetes mellitus in patients chronically infected with hepatitis C virus. The identification of potential inflammatory mediators involved in the crosstalk between hepatitis C virus and the axis pancreas-liver remains important issues that deserve further investigations.

Interleukin-10 promoter gene polymorphisms are associated with the first major depressive episode in chronic hepatitis C patients

AIMS

To investigate the association of IL10 SNPs in chronic hepatitis C (CHC) patients with and without the first major depressive episode (MDE), as well as their association with plasma levels of target cytokines.

METHODS

A hundred and thirty two CHC patients (32 with and 100 without first MDE) and 98 controls were prospectively enrolled in this cross-sectional study. MDE was diagnosed by a psychiatrist, using the Mini International Neuropsychiatric Interview Plus 5.0. IL10 polymorphisms (-1082 G/A, -819C/T and -592C/A IL10 SNPs) were evaluated by Taqman SNP genotyping assay. Plasma concentrations of IL-2, IL-6, IL-10, IFN-γ and TNF-α were determined using the Human Th1/Th2 Cytometric Bead Array kit. The associations were investigated by logistic models.

RESULTS

The frequencies of the studied IL10 SNPs did not differ between the CHC patients and controls. The first MDE was positive and independently associated with the IL10-1082*A, IL10-819*T and IL10-592*A (ATA) low producer haplotype (OR = 1.50; 95% CI = 1.11-2.04; P = 0.009) and current alcohol misuse (OR = 4.29; 95% CI = 1.22-15.05; P = 0.02), and inversely associated with increasing age (OR = 0.94; 95% CI = 0.91-0.98; P = 0.006). In addition, plasma level of TNF-α was significantly higher in the carriers than in the non-carriers of the IL10 ATA haplotype in patients with the first MDE. The IL-10 and IL-2 plasma levels were significantly higher in the carriers than in non-carriers of the IL10 GCC high producer haplotype, demonstrating the functionality of the studied IL10 polymorphisms.

CONCLUSIONS

This is the first study to demonstrate that the IL10 low producer ATA haplotype is associated with the first MDE in patients with CHC.

Increased serum gastrin in patients with different clinical forms of Chagas disease coinfected with Helicobacter pylori

Trypanosoma cruzi and Helicobacter pylori (HP) are pathogens that cause chronic diseases and have been associated with hypergastrinemia. The aim of this study was to evaluate the fasting gastrin levels in patients with different clinical forms of Chagas disease (CD), coinfected or not by HP. The enrolled individuals were outpatients attending at the university hospital. HP infection was assessed by serology and 13 C-urea breath test. Fasting serum gastrin concentration was measured by chemiluminescence assay. Gastric endoscopic and histological features were also evaluated. Associations between CD and serum gastrin level were evaluated in a logistical model, adjusting for age, gender and HP status. A total of 113 patients were evaluated (45 with Chagas disease and 68 controls). In the multivariate analysis, increasing serum gastrin levels (OR= 1.02; 95% CI= 1.01-1.12), increasing age (OR= 1.05; 95% CI= 1.02 - 1.09) and HP-positive status (OR = 2.88; 95% CI = 1.10 - 7.51) remained independently associated with CD. The serum gastrin levels were significantly higher in the group of patients with the cardiodigestive form ( P = 0.03) as well as with digestive form ( P = <0.001) of Chagas disease than in the controls. In conclusion, patients with cardiodigestive and digestive clinical forms of CD have increased basal serum gastrin levels in comparison with controls. Moreover, we also demonstrated that H. pylori coinfection contributes to the hypergastrinemia shown in CD.

The combined polymorphisms of interleukin-6-174GG genotype and interleukin-10 ATA haplotype are associated with a poor quality of life in patients with chronic hepatitis C

PURPOSE

Chronic hepatitis C (CHC) is associated with a decreased health-related quality of life (HRQOL). More recent studies have pointed toward a genetic basis of patient-reported quality of life outcomes. Taking into account that the influence of single-nucleotide polymorphisms (SNPs) on the HRQOL of CHC patients has not been studied, we investigated the combined IL10-1082G/A, - 819C/T, and - 592C/A SNPs, and IL6-174G/C SNP. We also evaluated the association between demographic, clinical, psychiatric, virological, and genetic variables with domains and summaries of HRQOL in CHC patients.

METHODS

132 consecutive CHC patients and 98 controls underwent psychiatric evaluation by using the Mini International Neuropsychiatric Interview. HRQOL was assessed by a generic questionnaire, the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36), and by the specific Liver Disease Quality of Life Questionnaire (LDQOL). IL6 and IL10 polymorphisms were evaluated by Taqman SNP genotyping assay. Multivariate analysis was used to evaluate the associations.

RESULTS

Major depressive disorder was associated with lower SF-36 and LDQOL scores in seven and ten domains, respectively. Diabetes and hypertension were also associated with reduced HRQOL. CHC patients carrying the combination of IL10 ATA haplotype/IL6-GG genotype had lower scores in the SF-36-physical functioning domain, and reduced scores in the LDQOL effects of liver disease on activities of daily living, quality of social interaction, and sexual function domains than the non-carriers of the combined haplotype/genotype.

CONCLUSION

This is the first study to demonstrate that combined IL6 high-producer GG genotype and IL10 low-producer ATA haplotype is associated with poorer HRQOL in CHC patients.

Th1 immune response to H. pylori infection varies according to the age of the patients and influences the gastric inflammatory patterns

To compare children and adults in respect to the effect of H. pylori infection on the gastric concentrations of cytokines linked to innate and Th1 immune response, as well as to investigate the changes in the gastric concentrations of the studied cytokines according to the age. We studied 245 children (142 H. pylori-negative and 103 H. pylori-positive) and 140 adults (40 H. pylori-negative and 100 H. pylori-positive). The gastric concentrations of cytokines representative of the innate and Th1 response were higher in the H. pylori-positive than in the -negative children and adults. The gastric concentrations of IL-1α and TNF-α were significantly higher, while those of IL-2, IL-12p70 and IFN-γ were lower in the infected children than in the infected adults. In the infected children, the gastric concentration of IL-1α, IL-2, IL-12p70 and IFN-γ increased, whereas in adults, the gastric concentrations of IFN-γ and IL-12p70 decreased with the aging. Increased gastric concentration of Th1 associated cytokines correlated with increased degree of gastritis that is the background lesion for the development of the H. pylori associated severe diseases. Concluding, Th1 response to H. pylori infection varies according to the age and seems to have determinant implication in the H. pylori infection outcomes.

Seroprevalence of Helicobacter pylori infection in chagasic and nonchagasic patients from the same geographical region of Brazil

INTRODUCTION

In this study, we evaluated the seroprevalence of Helicobacter pylori infection among chagasic and non-chagasic subjects as well as among the subgroups of chagasic patients with the indeterminate, cardiac, digestive, and cardiodigestive clinical forms.

METHODS

The evaluated subjects were from the Triângulo Mineiro region, Minas Gerais, Brazil. Chagasic patients showed positive reactions to the conventional serological tests used and were classified according to the clinical form of their disease. Immunoglobulin G antibodies specific to H. pylori were measured using a commercial enzyme-linked immunosorbent assay kit.

RESULTS

The overall H. pylori prevalence was 77.1% (239/310) in chagasic and 69.1% (168/243) in non-chagasic patients. This difference was statistically significant even after adjustment for age and sex (odds ratio = 1.57; 95% confidence interval, 1.02-2.42; p = 0.04) in multivariate analysis. The prevalence of infection increased with age in the non-chagasic group (p = 0.007, χ² for trend), but not in the chagasic group (p = 0.15, χ² for trend). H. pylori infection was not associated with digestive or other clinical forms of Chagas disease (p = 0.27).

CONCLUSIONS

Our findings demonstrate that chagasic patients have a higher prevalence of H. pylori compared to non-chagasic subjects; a similar prevalence was found among the diverse clinical forms of the disease. The factors contributing to the frequent co-infection with H. pylori and Trypanosoma cruzi as well as its effects on the clinical outcome deserve further study.

Helicobacter pylori virulence factors as tools to study human migrations

Helicobacter pylori is one of the most common infections worldwide. In most individuals it consists in a lifelong host-pathogen relationship without consequences, but in some subjects it is associated with peptic ulcer disease and gastric cancer. Polymorphism in genes that code bacterial virulence factors, cagA and vacA, are independently associated with the infection severe outcomes and are geographically diverse. In the last decade, accumulated knowledge allowed to characterize typical H. pylori strain patterns for all the major human populations; patterns that can be used to study the origin of specific human groups. Thus, the presence or absence of cagA, cagA EPIYA genotypes, and vacA subtypes can be used as tools to study not only the geographic origin of specific human populations, but also to identify markers of historical contact between different ethnicities. We report here a study including a set of native Amazon Amerindians that had supposedly been some, but little, contact with European Brazilian colonizer and/or African slaves. They harbor H. pylori strains in a mixed pattern with Asian and Iberian Peninsula characteristics. It is possible that this finding represents H. pylori recombination upon short contact between human groups. Alternatively, it could be due to a founder effect from a small cluster of Asian origin native Americans.