Serologic and stool antigen assay of Helicobacter pylori infection in hyperemesis gravidarum: which test is useful during early pregnancy?

Hyperemesis Gravidarum in First-Trimester Pregnant Saudi Women: Is Helicobacter pylori a Risk Factor?

Introduction

Hyperemesis gravidarum (HG) is a serious complication of pregnancy involving nausea and vomiting which affects all facets of the lives of many women. Helicobacter pylori infection has been linked to HG in some regions of the world. However, the prevalence of H. pylori in Saudi Arabian pregnant women and its link to HG has not been the subject of previous research. Detecting and treating H. pylori infection in women early in their pregnancies may lower the likelihood of adverse maternal outcomes. This study aims to assess the connection between the pathogenesis of HG and H. pylori infection in this population.

Methods

Forty-five pregnant women with HG were recruited from the outpatient clinic for antenatal care in the Gynecology and Obstetrics Department at King Abdulaziz University Hospital. Forty-five pregnant women without HG were matched as controls. Both groups underwent testing for the H. pylori antigen in stool samples.

Results

A statistically significant difference (P < 0.05) was observed between the cases and controls in terms of the occurrence of H. pylori. Thirty-eight women in the HG group (84.4%) tested positive for H. pylori, while the same was true of only 20 of the controls (44.4%). The mean level of blood hemoglobin in positive cases was significantly lower than that in negative cases (9.56 ± 1.29 vs. 11.90 ± 1.18 g/dl, P = 0.012).

Conclusion

H. pylori may play a contributing role in the presence of HG in the study population. It may be included with other investigations of HG, especially with cases that do not respond to conventional management and continue into the second trimester. Women with H. pylori were also more likely to suffer from anemia compared to those without the infection. For this reason, those working with pregnant women should pay close attention to those infected with H. pylori. Additional large case–control studies are necessary to better understand the part H. pylori plays and the pathogenesis of HG.

Helicobacter pylori is Associated with Less Fistulizing, Stricturing, and Active Colitis in Crohn's Disease Patients

Introduction A potential protective role of Helicobacter pylori (HP) infection against the development of Crohn's disease (CD) has been postulated. There is a lack of studies evaluating the association of HP with CD phenotypes. The aim of this study was to investigate the clinical features and disease activity of patients with CD who were diagnosed with HP infection. Methods The charts of 306 consecutive patients from the inflammatory bowel disease (IBD) database at the University of Florida College of Medicine, Jacksonville from January 2014 to July 2016 were reviewed. Ninety-one CD patients who were tested for HP were included, and the frequencies of strictures, fistulas, and colitis in surveillance biopsies in these patients were evaluated. Results Of the 91 CD patients tested for HP, 19 had HP infection. A total of 44 patients had fistulizing/stricturing disease, and 62 patients had active colitis. In the univariate analysis, patients with HP infection had less fistulizing/stricturing disease (21.1% vs. 55.6%, p = 0.009) and less active colitis (42.1% vs. 77.1%, p = 0.005). In the multivariate analysis, HP infection remained as a protective factor for fistulizing/stricturing disease phenotype (OR: 0.22; 95%CI: 0.06-0.97; p = 0.022) and active colitis (OR: 0.186; 95%CI: 0.05-0.65; p = 0.010). Conclusion HP infection was independently associated with less fistulizing/stricturing disease and less active colitis in CD patients. Our study suggests CD patients with a history of HP infection are less prone to complications.

Non-invasive diagnostic tests for Helicobacter pylori infection

BACKGROUND

Helicobacter pylori (H pylori) infection has been implicated in a number of malignancies and non-malignant conditions including peptic ulcers, non-ulcer dyspepsia, recurrent peptic ulcer bleeding, unexplained iron deficiency anaemia, idiopathic thrombocytopaenia purpura, and colorectal adenomas. The confirmatory diagnosis of H pylori is by endoscopic biopsy, followed by histopathological examination using haemotoxylin and eosin (H & E) stain or special stains such as Giemsa stain and Warthin-Starry stain. Special stains are more accurate than H & E stain. There is significant uncertainty about the diagnostic accuracy of non-invasive tests for diagnosis of H pylori.

OBJECTIVES

To compare the diagnostic accuracy of urea breath test, serology, and stool antigen test, used alone or in combination, for diagnosis of H pylori infection in symptomatic and asymptomatic people, so that eradication therapy for H pylori can be started.

SEARCH METHODS

We searched MEDLINE, Embase, the Science Citation Index and the National Institute for Health Research Health Technology Assessment Database on 4 March 2016. We screened references in the included studies to identify additional studies. We also conducted citation searches of relevant studies, most recently on 4 December 2016. We did not restrict studies by language or publication status, or whether data were collected prospectively or retrospectively.

SELECTION CRITERIA

We included diagnostic accuracy studies that evaluated at least one of the index tests (urea breath test using isotopes such as 13C or 14C, serology and stool antigen test) against the reference standard (histopathological examination using H & E stain, special stains or immunohistochemical stain) in people suspected of having H pylori infection.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the references to identify relevant studies and independently extracted data. We assessed the methodological quality of studies using the QUADAS-2 tool. We performed meta-analysis by using the hierarchical summary receiver operating characteristic (HSROC) model to estimate and compare SROC curves. Where appropriate, we used bivariate or univariate logistic regression models to estimate summary sensitivities and specificities.

MAIN RESULTS

We included 101 studies involving 11,003 participants, of which 5839 participants (53.1%) had H pylori infection. The prevalence of H pylori infection in the studies ranged from 15.2% to 94.7%, with a median prevalence of 53.7% (interquartile range 42.0% to 66.5%). Most of the studies (57%) included participants with dyspepsia and 53 studies excluded participants who recently had proton pump inhibitors or antibiotics.There was at least an unclear risk of bias or unclear applicability concern for each study.Of the 101 studies, 15 compared the accuracy of two index tests and two studies compared the accuracy of three index tests. Thirty-four studies (4242 participants) evaluated serology; 29 studies (2988 participants) evaluated stool antigen test; 34 studies (3139 participants) evaluated urea breath test-13C; 21 studies (1810 participants) evaluated urea breath test-14C; and two studies (127 participants) evaluated urea breath test but did not report the isotope used. The thresholds used to define test positivity and the staining techniques used for histopathological examination (reference standard) varied between studies. Due to sparse data for each threshold reported, it was not possible to identify the best threshold for each test.Using data from 99 studies in an indirect test comparison, there was statistical evidence of a difference in diagnostic accuracy between urea breath test-13C, urea breath test-14C, serology and stool antigen test (P = 0.024). The diagnostic odds ratios for urea breath test-13C, urea breath test-14C, serology, and stool antigen test were 153 (95% confidence interval (CI) 73.7 to 316), 105 (95% CI 74.0 to 150), 47.4 (95% CI 25.5 to 88.1) and 45.1 (95% CI 24.2 to 84.1). The sensitivity (95% CI) estimated at a fixed specificity of 0.90 (median from studies across the four tests), was 0.94 (95% CI 0.89 to 0.97) for urea breath test-13C, 0.92 (95% CI 0.89 to 0.94) for urea breath test-14C, 0.84 (95% CI 0.74 to 0.91) for serology, and 0.83 (95% CI 0.73 to 0.90) for stool antigen test. This implies that on average, given a specificity of 0.90 and prevalence of 53.7% (median specificity and prevalence in the studies), out of 1000 people tested for H pylori infection, there will be 46 false positives (people without H pylori infection who will be diagnosed as having H pylori infection). In this hypothetical cohort, urea breath test-13C, urea breath test-14C, serology, and stool antigen test will give 30 (95% CI 15 to 58), 42 (95% CI 30 to 58), 86 (95% CI 50 to 140), and 89 (95% CI 52 to 146) false negatives respectively (people with H pylori infection for whom the diagnosis of H pylori will be missed).Direct comparisons were based on few head-to-head studies. The ratios of diagnostic odds ratios (DORs) were 0.68 (95% CI 0.12 to 3.70; P = 0.56) for urea breath test-13C versus serology (seven studies), and 0.88 (95% CI 0.14 to 5.56; P = 0.84) for urea breath test-13C versus stool antigen test (seven studies). The 95% CIs of these estimates overlap with those of the ratios of DORs from the indirect comparison. Data were limited or unavailable for meta-analysis of other direct comparisons.

AUTHORS' CONCLUSIONS

In people without a history of gastrectomy and those who have not recently had antibiotics or proton ,pump inhibitors, urea breath tests had high diagnostic accuracy while serology and stool antigen tests were less accurate for diagnosis of Helicobacter pylori infection.This is based on an indirect test comparison (with potential for bias due to confounding), as evidence from direct comparisons was limited or unavailable. The thresholds used for these tests were highly variable and we were unable to identify specific thresholds that might be useful in clinical practice.We need further comparative studies of high methodological quality to obtain more reliable evidence of relative accuracy between the tests. Such studies should be conducted prospectively in a representative spectrum of participants and clearly reported to ensure low risk of bias. Most importantly, studies should prespecify and clearly report thresholds used, and should avoid inappropriate exclusions.

A meta-analysis of the association between Helicobacter pylori (H. pylori) infection and hyperemesis gravidarum

BACKGROUND

Hyperemesis gravidarum remains a common, distressing, and significant yet poorly understood disorder during pregnancy. The association between maternal Helicobacter pylori (H. pylori) infection and hyperemesis gravidarum has been increasingly recognized and investigated. This study thus aimed to provide an updated review and meta-analysis of the topic.

METHODS

Using the search terms (H. pyloriOR Helicobacter ORHelicobacter pyloriOR infection) AND (pregnancy OR emesis OR hyperemesis gravidarum OR nausea OR vomiting), a preliminary search on the PubMed, Ovid, Web of Science, Google Scholar, and WanFang database yielded 372 papers published in English between January 1st, 1960 and June 1st, 2017.

RESULTS

A total of 38 cross-sectional and case-control studies, with a total of 10 289 patients were eligible for review. Meta-analysis revealed a significant association between H. pylori infection and hyperemesis gravidarum during pregnancy, with a pooled odds ratio of 1.348 (95% CI: 1.156-1.539, P < .001). Subgroup analysis found that serologic and stool antigen tests were comparable methods of detecting H. pylori as they yielded similar odds ratios.

LIMITATIONS

Although the studies did not have high heterogeneity (I2  = 28%), publication bias was observed, and interstudy discrepancies in the diagnostic criteria adopted for hyperemesis gravidarum limit the reliability of findings. Also, 15 of the included studies were from the same country (Turkey), which could limit the generalizability of current findings. The prevalence of H. pylori infection varies throughout the world, and there may also be pathogenic differences as most strains of H. pylori in East Asia carry the cytotoxin-associated gene A gene.

CONCLUSION

H. pylori infection was associated with an increased likelihood of hyperemesis gravidarum during pregnancy. Given the high prevalence of H. pylori infections worldwide, detecting H. pylori infection and the eradication of maternal H. pylori infection could be part of maternal hyperemesis gravidarum management. Further confirmation with robust longitudinal studies and mechanistic investigations are needed.

The Management of Nausea and Vomiting of Pregnancy

OBJECTIVES

To review the evidence-based management of nausea and vomiting of pregnancy and hyperemesis gravidarum.

EVIDENCE

MEDLINE and Cochrane database searches were performed using the medical subject headings of treatment, nausea, vomiting, pregnancy, and hyperemesis gravidarum. The quality of evidence reported in these guidelines has been described using the Evaluation of Evidence criteria outlined in the Report of the Canadian Task Force on Preventative Health Care.

BENEFITS

Nausea and vomiting of pregnancy has a profound effect on women's health and quality of life during pregnancy as well as a financial impact on the health care system, and its early recognition and management is recommended. COST: Costs, including hospitalizations, additional office visits, and time lost from work, may be reduced if nausea and vomiting in pregnancy is treated early.

RECOMMENDATIONS

Loop-Mediated Isothermal Amplification as a Fast Noninvasive Method of Helicobacter pylori Diagnosis

BACKGROUND

Helicobacter pylori infection is etiologically associated with some important health problems such as gastric cancer. Because of the high clinical importance of H. pylori infection, development of a noninvasive test for the detection of H. pylori is desirable.

METHODS

In this study, a loop-mediated isothermal amplification (LAMP) targeted ureC of H. pylori was evaluated on 100 stool specimens and compared with a stool antigen test. Culture and rapid urease test were considered as gold standards.

RESULTS

The overall detection rate of the fecal antigen test and LAMP was 58% and 82%, respectively. The analytical sensitivity of the fecal antigen test and LAMP was 500 and 10 H. pylori cells/g and 10 fg DNA/reaction, which is equal to six H. pylori genome.

CONCLUSION

LAMP technique has been characterized by high sensitivity and low detection limit for the detection of H. pylori in stool specimen. Clinical diagnostic performance of LAMP was better than the stool antigen test.

Helicobacter pylori Infection Is Associated with an Increased Risk of Hyperemesis Gravidarum: A Meta-Analysis

Background. Several studies have shown a possible involvement of Helicobacter pylori (H. pylori) infection in individuals with hyperemesis gravidarum (HG), but the relationship remains controversial. This meta-analysis was performed to validate and strengthen the association between HG and H. pylori infection. Methods. PubMed, Embase, and Web of Science databases up to March 20, 2014, were searched to select studies on the prevalence of H. pylori infection between pregnant women with HG and the normal pregnant control subjects. Results. Of the HG cases, 1289 (69.6%) were H. pylori-positive; however, 1045 (46.2%) were H. pylori-positive in control group. Compared to the non-HG normal pregnant controls, infection rate of H. pylori was significantly higher in pregnant women with HG (OR = 3.34, 95% CI: 2.32–4.81, P < 0.001). Subgroup analysis indicated that H. pylori infection was a risk factor of HG in Asia, Africa, and Oceania, especially in Africa (OR = 12.38, 95% CI: 7.12–21.54, P < 0.001). Conclusions. H. pylori should be considered one of the risk factors of HG, especially in the developing countries. H. pylori eradication could be considered to relieve the symptoms of HG in some intractable cases.

The outpatient management and special considerations of nausea and vomiting in pregnancy

With 50-90% of pregnant women experiencing nausea and vomiting of pregnancy (NVP), the burden of illness can become quite significant if symptoms are under-treated and/or under-diagnosed, thus allowing for progression of the disease. The majority of these women will necessitate at least one visit with a provider to specifically address NVP, and up to 10% or greater will require pharmacotherapy after failure of conservative measures to adequately control symptoms. As a result, initiation of prompt and effective treatment in the outpatient setting is ideal. Once NVP is diagnosed and treatment is started, it is crucial to track symptoms in order to assess for a decrease in or resolution of symptoms as well as an escalation in symptoms requiring additional therapy. Of note, co-existing gastroesophageal reflux disease (GERD), Helicobacter pylori infection, and psychosocial factors may have a negative impact on the management of NVP. Ultimately, every woman has her own perception of disease severity and desire for treatment. It is critical that both the provider and patient be proactive in the diagnosis and management of NVP.

Beyond the stomach: An updated view of Helicobacter pylori pathogenesis, diagnosis, and treatment

Helicobacter pylori (H. pylori) is an extremely common, yet underappreciated, pathogen that is able to alter host physiology and subvert the host immune response, allowing it to persist for the life of the host. H. pylori is the primary cause of peptic ulcers and gastric cancer. In the United States, the annual cost associated with peptic ulcer disease is estimated to be $6 billion and gastric cancer kills over 700000 people per year globally. The prevalence of H. pylori infection remains high (> 50%) in much of the world, although the infection rates are dropping in some developed nations. The drop in H. pylori prevalence could be a double-edged sword, reducing the incidence of gastric diseases while increasing the risk of allergies and esophageal diseases. The list of diseases potentially caused by H. pylori continues to grow; however, mechanistic explanations of how H. pylori could contribute to extragastric diseases lag far behind clinical studies. A number of host factors and H. pylori virulence factors act in concert to determine which individuals are at the highest risk of disease. These include bacterial cytotoxins and polymorphisms in host genes responsible for directing the immune response. This review discusses the latest advances in H. pylori pathogenesis, diagnosis, and treatment. Up-to-date information on correlations between H. pylori and extragastric diseases is also provided.

Diagnostic markers for hyperemesis gravidarum: a systematic review and metaanalysis

OBJECTIVE

Currently, there is no consensus on the definition of hyperemesis gravidarum (HG; protracted vomiting in pregnancy) and no single widely used set of diagnostic criteria for HG. The various definitions rely on symptoms, sometimes in combination with laboratory tests. Through a systematic review, we aimed to summarize available evidence on the diagnostic value of biomarkers for HG. This could assist diagnosis and may shed light on the, as yet, not understood cause of the disorder.

STUDY DESIGN

We searched Medline and Embase for articles about diagnostic biomarkers for either the presence or severity of HG or nausea and vomiting of pregnancy. We defined HG as any combination of nausea, vomiting, dehydration, weight loss, or hospitalization for nausea and/or vomiting in pregnancy, in the absence of any other obvious cause for these complaints.

RESULTS

We found 81 articles on 9 biomarkers. Although 65% of all studies included only HG cases with ketonuria, we did not find an association between ketonuria and presence or severity of HG in 5 studies reporting on this association. Metaanalysis, with the use of the hierarchical summary receiver operating characteristics model, yielded an odds ratio of 3.2 (95% confidence interval, 2.0-5.1) of Heliobacter pylori for HG, as compared with asymptomatic control subjects (sensitivity, 73%; specificity, 55%). Studies on human chorionic gonadotropin and thyroid hormones, leptin, estradiol, progesterone, and white blood count showed inconsistent associations with HG; lymphocytes tended to be higher in women with HG.

CONCLUSION

We did not find support for the use of ketonuria in the diagnosis of HG. H pylori serology might be useful in specific patients.

Helicobacter pylori infection and gastrointestinal symptoms on Chilean pregnant women

Objective: the aim of this research was to determine the prevalence of Helicobacter pylori infection on Chilean pregnant women and its relationship with the appearance and severity of hyperemesis and dyspepsia. Methods: quantitative study of prevalence in a transversal cut with variable analysis. The sample was taken from 274 Chilean pregnant women from the Bío Bío province through vein puncture between June and December, 2005. Pregnant women were informed of this study, interviewed and signed an informed consent. The samples were processed using ImmunoComb II Helicobacter pylori IgG kit. Statistical analysis was performed by means of the Statistical Package for Social Sciences (SPSS) Program. Results: out of the total number of pregnant women, 68.6% showed infection by Helicobacter pylori. 79.6% of the total sample had symptoms of dyspepsia, and 72.5% of this group presented Helicobacter pylori infection. 12.4% showed pregnancy hyperemesis; among them, 79.4% were infected with Helicobacter pylori. 73.4% of the pregnant women that showed gastric discomfort during the first three months had Helicobacter pylori infection. 53.7% of them continued with gastric discomfort after the first three months; of those, 95.8% were infected. Helicobacter pylori infection was present only in 1.5% of pregnant women without gastric discomfort. Conclusion: both, gastric discomfort of pregnant women and the continuity of severe symptoms of dyspepsia and hyperemesis after the first three months of gestation are significantly correlated with Helicobacter pylori infection.

Helicobacter pylori and pregnancy-related disorders

Helicobacter pylori (H. pylori) infection is investigated in gastric diseases even during pregnancy. In particular, this Gram-negative bacterium seems to be associated with hyperemesis gravidarum, a severe form of nausea and vomiting during pregnancy. During the last decade, the relationship among H. pylori and several extra-gastric diseases strongly emerged in literature. The correlation among H. pylori infection and pregnancy-related disorders was mainly focused on iron deficiency anemia, thrombocytopenia, fetal malformations, miscarriage, pre-eclampsia and fetal growth restriction. H. pylori infection may have a role in the pathogenesis of various pregnancy-related disorders through different mechanisms: depletion of micronutrients (iron and vitamin B₁₂) in maternal anemia and fetal neural tube defects; local or systemic induction of pro-inflammatory cytokines release and oxidative stress in gastrointestinal disorders and pre-eclampsia; cross-reaction between specific anti-H. pylori antibodies and antigens localized in placental tissue and endothelial cells (pre-eclampsia, fetal growth restriction, miscarriage). Since H. pylori infection is most likely acquired before pregnancy, it is widely believed that hormonal and immunological changes occurring during pregnancy could activate latent H. pylori with a negative impact not only on maternal health (nutritional deficiency, organ injury, death), but also on the fetus (insufficient growth, malformation, death) and sometime consequences can be observed later in life. Another important issue addressed by investigators was to determine whether it is possible to transmit H. pylori infection from mother to child and whether maternal anti-H. pylori antibodies could prevent infant’s infection. Studies on novel diagnostic and therapeutic methods for H. pylori are no less important, since these are particularly sensitive topics in pregnancy conditions. It could be interesting to study the possible correlation between H. pylori infection and other pregnancy-related diseases of unknown etiology, such as gestational diabetes mellitus, obstetric cholestasis and spontaneous preterm delivery. Since H. pylori infection is treatable, the demonstration of its causative role in pregnancy-related disorders will have important social-economic implications.

Comparison of stool antigen test with gastric biopsy for the detection of Helicobacter Pylori infection

Objective: Helicobacter Pylori (H.pylori) is one of the most important causes of dyspepsia and diagnosis can be made by invasive or non-invasive methods. One of the non-invasive methods, H.pylori stool antigen test (HpSA) is simple, fast and relatively inexpensive. According to this view with regard to gastric biopsy as a gold standard the sensitivity, specificity, positive and negative predictive values of this method were calculated.

Methodology: Stool samples of 61 patients who underwent upper endoscopy and gastric biopsy due to dyspepsia were evaluated for H. Pylori stool antigen using sandwich ELISA method.

Results: From the 61 patients who participated in this study, H.pylori was diagnosed in 38 (62.3%) gastric biopsies, 25(66%) of these had positive HpSA test. Also, of 27 (37.7%) positive HpSA cases, H.pylori was seen in 25 gastric biopsies. For this method, sensitivity of 66% with 93% positive predictive value was calculated. Also, 91% specificity with 62% negative predictive value was estimated.

Conclusion: High positive HpSA indicates high risk of H.pylori infection and high specificity shows that the likelihood of false positive is low. Therefore, physicians can trust on this method and start patient`s treatment.

Review of NVP and HG and Early Pharmacotherapeutic Intervention

NVP occurs in 50–90% of pregnancies, making it a common medical condition in pregnancy. Women present differently with any combination of signs and symptoms. It is appropriate to take the pregnancy-related versus nonpregnancy-related approach when determining the cause of nausea and vomiting but other causes should be considered. The most common etiologies for NVP include the hormonal changes associated with pregnancy, the physiologic changes in the gastrointestinal tract, and a genetic predisposition. Up to 10% of women will require pharmacotherapy to treat the symptoms of NVP despite conservative measures. ACOG currently recommends that a combination of oral pyridoxine hydrochloride and doxylamine succinate be used as first-line treatment for NVP if pyridoxine monotherapy does not relieve symptoms. A review of NVP and early pharmacotherapeutic management is presented due to the fact that NVP is largely undertreated, and investigations into the safe and effective pharmacotherapies available to treat NVP are lacking.