Clinical and economic impact of "triple therapy" for Helicobacter pylori eradication on peptic ulcer disease in Australia

Back to the Basics of SARS-CoV-2 Biochemistry: Microvascular Occlusive Glycan Bindings Govern Its Morbidities and Inform Therapeutic Responses

Consistent with the biochemistry of coronaviruses as well established over decades, SARS-CoV-2 makes its initial attachment to host cells through the binding of its spike protein (SP) to sialylated glycans (containing the monosaccharide sialic acid) on the cell surface. The virus can then slide over and enter via ACE2. SARS-CoV-2 SP attaches particularly tightly to the trillions of red blood cells (RBCs), platelets and endothelial cells in the human body, each cell very densely coated with sialic acid surface molecules but having no ACE2 or minimal ACE2. These interlaced attachments trigger the blood cell aggregation, microvascular occlusion and vascular damage that underlie the hypoxia, blood clotting and related morbidities of severe COVID-19. Notably, the two human betacoronaviruses that express a sialic acid-cleaving enzyme are benign, while the other three-SARS, SARS-CoV-2 and MERS-are virulent. RBC aggregation experimentally induced in several animal species using an injected polysaccharide caused most of the same morbidities of severe COVID-19. This glycan biochemistry is key to disentangling controversies that have arisen over the efficacy of certain generic COVID-19 treatment agents and the safety of SP-based COVID-19 vaccines. More broadly, disregard for the active physiological role of RBCs yields unreliable or erroneous reporting of pharmacokinetic parameters as routinely obtained for most drugs and other bioactive agents using detection in plasma, with whole-blood levels being up to 30-fold higher. Appreciation of the active role of RBCs can elucidate the microvascular underpinnings of other health conditions, including cardiovascular disease, and therapeutic opportunities to address them.

Sialylated Glycan Bindings from SARS-CoV-2 Spike Protein to Blood and Endothelial Cells Govern the Severe Morbidities of COVID-19

Consistent with well-established biochemical properties of coronaviruses, sialylated glycan attachments between SARS-CoV-2 spike protein (SP) and host cells are key to the virus's pathology. SARS-CoV-2 SP attaches to and aggregates red blood cells (RBCs), as shown in many pre-clinical and clinical studies, causing pulmonary and extrapulmonary microthrombi and hypoxia in severe COVID-19 patients. SARS-CoV-2 SP attachments to the heavily sialylated surfaces of platelets (which, like RBCs, have no ACE2) and endothelial cells (having minimal ACE2) compound this vascular damage. Notably, experimentally induced RBC aggregation in vivo causes the same key morbidities as for severe COVID-19, including microvascular occlusion, blood clots, hypoxia and myocarditis. Key risk factors for COVID-19 morbidity, including older age, diabetes and obesity, are all characterized by markedly increased propensity to RBC clumping. For mammalian species, the degree of clinical susceptibility to COVID-19 correlates to RBC aggregability with p = 0.033. Notably, of the five human betacoronaviruses, the two common cold strains express an enzyme that releases glycan attachments, while the deadly SARS, SARS-CoV-2 and MERS do not, although viral loads for COVID-19 and the two common cold infections are similar. These biochemical insights also explain the previously puzzling clinical efficacy of certain generics against COVID-19 and may support the development of future therapeutic strategies for COVID-19 and long COVID patients.

When Characteristics of Clinical Trials Require Per-Protocol as Well as Intention-to-Treat Outcomes to Draw Reliable Conclusions: Three Examples

Under exceptional circumstances, including high rates of protocol non-compliance, per-protocol (PP) analysis can better indicate the real-world benefits of a medical intervention than intention-to-treat (ITT) analysis. Exemplifying this, the first randomized clinical trial (RCT) considered found that colonoscopy screenings were marginally beneficial, based upon ITT analysis, with only 42% of the intervention group actually undergoing the procedure. However, the study authors themselves concluded that the medical efficacy of that screening was a 50% reduction in colorectal cancer deaths among that 42% PP group. The second RCT found a ten-fold reduction in mortality for a COVID-19 treatment drug vs. placebo by PP analysis, but only a minor benefit by ITT analysis. The third RCT, conducted as an arm of the same platform trial as the second RCT, tested another COVID-19 treatment drug and reported no significant benefit by ITT analysis. Inconsistencies and irregularities in the reporting of protocol compliance for this study required consideration of PP outcomes for deaths and hospitalizations, yet the study coauthors refused to disclose them, instead directing inquiring scientists to a data repository which never held the study's data. These three RCTs illustrate conditions under which PP outcomes may differ significantly from ITT outcomes and the need for data transparency when these reported or indicated discrepancies arise.

Helicobacter pylori infection

Helicobacter pylori infection causes chronic gastritis, which can progress to severe gastroduodenal pathologies, including peptic ulcer, gastric cancer and gastric mucosa-associated lymphoid tissue lymphoma. H. pylori is usually transmitted in childhood and persists for life if untreated. The infection affects around half of the population in the world but prevalence varies according to location and sanitation standards. H. pylori has unique properties to colonize gastric epithelium in an acidic environment. The pathophysiology of H. pylori infection is dependent on complex bacterial virulence mechanisms and their interaction with the host immune system and environmental factors, resulting in distinct gastritis phenotypes that determine possible progression to different gastroduodenal pathologies. The causative role of H. pylori infection in gastric cancer development presents the opportunity for preventive screen-and-treat strategies. Invasive, endoscopy-based and non-invasive methods, including breath, stool and serological tests, are used in the diagnosis of H. pylori infection. Their use depends on the specific individual patient history and local availability. H. pylori treatment consists of a strong acid suppressant in various combinations with antibiotics and/or bismuth. The dramatic increase in resistance to key antibiotics used in H. pylori eradication demands antibiotic susceptibility testing, surveillance of resistance and antibiotic stewardship.

Economic and health impacts of Helicobacter pylori eradication strategy for the treatment of peptic ulcer disease: A cost-effectiveness analysis

BACKGROUND

Most peptic ulcer cases are associated with Helicobacter pylori (H. pylori) infection or the use of nonsteroidal anti-inflammatory drugs (NSAIDs). H. pylori eradication therapy is recommended for the treatment of H. pylori-positive peptic ulcers. We aimed to assess and validate the cumulative economic and health effects of H. pylori eradication strategy for the treatment of peptic ulcers compared with PPI therapy strategy.

MATERIALS AND METHODS

We developed a cohort state-transition model for H. pylori eradication strategy and PPI therapy strategy over a lifetime horizon from a healthcare payer perspective. We targeted two hypothetical cohorts of H. pylori-positive patients with gastric and duodenal ulcers aged 20, 30, 40, 50, 60, 70, and 80. The main outcomes were costs, quality-adjusted life-years (QALYs), life expectancy life-years (LYs), incremental cost-effectiveness ratios, ulcer recurrence cases, and ulcer-associated deaths. One-way and probabilistic sensitivity analyses were conducted to assess the impact of uncertainty.

RESULTS

In the base-case analysis, H. pylori eradication strategy was less costly with greater benefits than PPI therapy strategy in all age groups. Cost-effectiveness was not sensitive to any variables in all age groups. Sensitivity analyses showed strong robustness of the results. From 2000 to 2020, H. pylori eradication strategy saved US$14.07 billion over a lifetime, increased 8.65 million QALYs and 1.23 million LYs over a lifetime, and prevented 551,298 ulcer recurrence cases and 59,465 ulcer-associated deaths, compared with PPI therapy strategy.

CONCLUSIONS

H. pylori eradication strategy not only has contributed significantly to preventing ulcer recurrence and reducing ulcer-associated deaths but also has resulted in great cost savings. All over the world, H. pylori eradication strategy is likely to have yielded a comparable magnitude of economic and health benefits, depending on the epidemiology of H. pylori-related peptic ulcers and the healthcare environment in each country.

The global, regional and national burden of peptic ulcer disease from 1990 to 2019: a population-based study

Background

Peptic ulcer disease (PUD) is a common digestive disorder, of which the prevalence decreased in the past few decades. However, the decreasing tendency has plateaued in recent years due to changes in risk factors associated with the etiology of PUD, such as non-steroidal anti-inflammatory drug use. In this study, we investigated the epidemiological and the sociodemographic characteristics of PUD in 204 countries and territories from 1990 to 2019 based on data from the Global Burden of Disease, Injuries and Risk Factors (GBD) Study.

Methods

Demographic characteristics and annual prevalence, incidence, mortality, disability-adjusted life years (DALYs) and age-standardized death rate (ASR) data associated with PUD were obtained and analyzed. According to the sociodemographic index (SDI), the numbers of patients, ASRs, estimated annual percentage changes and geographical distributions were assessed with a generalized linear model and presented in world maps. All evaluations of numbers and rates were calculated per 100,000 population with 95% uncertainty intervals (UIs).

Results

In 2019, the global prevalence of PUD was approximately 8.09 [95% UI 6.79–9.58] million, representing a 25.82% increase from 1990. The age-standardized prevalence rate was 99.40 (83.86–117.55) per 100,000 population in 2019, representing a decrease of 143.37 (120.54–170.25) per 100,000 population from 1990. The age-standardized DALY rate in 2019 was decreased by 60.64% [74.40 (68.96–81.95) per 100,000 population] compared to that in 1990. In both sexes, the numbers and ASRs of the prevalence, incidence, deaths and DALYs were higher in males than in females over 29 years. Regionally, South Asia had the highest age-standardized prevalence rate [156.62 (130.58–187.05) per 100,000 population] in 2019. A low age-standardized death rate was found in the high-income super-region. Among nations, Kiribati had the highest age-standardized prevalence rate [330.32 (286.98–379.81) per 100,000 population]. Regarding socioeconomic status, positive associations between the age-standardized prevalence, incidence, death rate, DALYs and SDI were observed globally in 2019.

Conclusions

Morbidity and mortality due to PUD decreased significantly from 1990 to 2019, while a gradual upward inclination has been observed in recent 15 years, which might be associated with changes in risk factors for PUD. Attention and efforts by healthcare administrators and society are needed for PUD prevention and control.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02130-2.

Sharing With Patients the Uncertainties Regarding the Management of Dyspepsia

Background: The management of patients with dyspepsia is uncertain. Some authors advocate endoscopy for all; others restrict endoscopy only to patients at high risk of gastric cancer, namely to those above an age threshold, or with a family history, dysphagia, loss of weight, anemia, or a childhood in Asian countries. Still others recommend various combinations between test-and-treat for Helicobacter pylori, anti-secretory treatment, and/or endoscopy.

Objective: To highlight the uncertainties in the choice between the various strategies and argue that these uncertainties should be shared with the patient.

Method: An overview of reported life expectancy, patient satisfaction, gastric cancer detection rates, symptom relief, and cost effectiveness of the management strategies for dyspepsia.

Main Findings: There are no randomized controlled trials of the effect of screening by endoscopy on mortality of patients with gastric cancer. Lower grades of evidence suggest that early diagnosis reduces this mortality. Analyses, which assume a survival benefit of early diagnosis, indicate that mass screening in countries of high incidence gastric cancer (> 10 cases per 100,000) and targeted screening of high-risk persons in countries of low-intermediate incidence (<10 cases per 100,000) is cost-effective at a willingness to pay of $20,000–50,000 per QALY. Prompt endoscopy appears to be best for patient satisfaction and gastric cancer detection, and test-and-treat for H pylori—for symptom relief and avoiding endoscopies.

Conclusions: The gain in life expectancy is the main source of uncertainty in the choice between management strategies. This choice should be shared with the patients after explaining uncertainties and eliciting their preferences.

Combinations of antibiotics and vonoprazan for the treatment of Helicobacter pylori infections-Exploratory study

BACKGROUND

Vonoprazan fumarate is a novel potassium-competitive acid blocker more effective in suppressing acid production than proton pump inhibitors (PPIs) and when combined with antibiotics has been used to eradicate Helicobacter pylori (H. pylori) infection. However, it has not yet been examined in an Australian setting. This study aimed to report on the efficacy and safety of vonoprazan-containing antibiotic combination therapies in the eradication of H. pylori.

METHODS

A single-center, exploratory, clinical review of patients 18 years or over, positive for H. pylori on Urea Breath Test (UBT), and/or histopathology who underwent a 10-day treatment of combination antibiotics plus vonoprazan between January 2017 and September 2019 was conducted. Eleven different combinations of antibiotics that included 2-5 different antibiotics predominantly amoxicillin, rifabutin, levofloxacin, furazolidone, nitazoxanide, and tetracycline were included. The eradication success was based on negative UBT results and/or histopathology results after the treatment. Descriptive statistics were summarized.

RESULTS

One hundred and fifty-three patients (Female n = 74, 48%) with a positive for H. pylori were treated with vonoprazan-containing antibiotic combination therapy during the study period. Of the 153 patients, 48 (31%) had previously failed a PPI-based H. pylori treatment. Follow-up was available for 66/153 (43%) patients. In those who completed follow-up, overall eradication was achieved in 97% (64/66) of patients. In the subgroup of patients treated for the first time, eradication was achieved in 100% (44/44). In those who had failed prior, non-vonoprazan-containing treatment, eradication was achieved in 91% (20/22) of patients.

CONCLUSIONS

Vonoprazan-containing antibiotic therapy is an effective H. pylori eradication treatment. It is capable of achieving 100% efficacy in patients treated for the first time and even 91% efficacy in patients with previous eradication failure. Subsequent studies utilizing a factorial design will be needed to optimize each regimen as most regimens contained more than two antibiotics.

Ivermectin: a multifaceted drug of Nobel prize-honoured distinction with indicated efficacy against a new global scourge, COVID-19

In 2015, the Nobel Committee for Physiology or Medicine, in its only award for treatments of infectious diseases since six decades prior, honoured the discovery of ivermectin (IVM), a multifaceted drug deployed against some of the world's most devastating tropical diseases. Since March 2020, when IVM was first used against a new global scourge, COVID-19, more than 20 randomized clinical trials (RCTs) have tracked such inpatient and outpatient treatments. Six of seven meta-analyses of IVM treatment RCTs reporting in 2021 found notable reductions in COVID-19 fatalities, with a mean 31% relative risk of mortality vs. controls. During mass IVM treatments in Peru, excess deaths fell by a mean of 74% over 30 days in its ten states with the most extensive treatments. Reductions in deaths correlated with the extent of IVM distributions in all 25 states with p < 0.002. Sharp reductions in morbidity using IVM were also observed in two animal models, of SARS-CoV-2 and a related betacoronavirus. The indicated biological mechanism of IVM, competitive binding with SARS-CoV-2 spike protein, is likely non-epitope specific, possibly yielding full efficacy against emerging viral mutant strains.