Assessing the efficacy of oral immunotherapy for the desensitisation of peanut allergy in children (STOP II): a phase 2 randomised controlled trial

SummaryBackgroundSmall studies suggest peanut oral immunotherapy (OIT) might be effective in the treatment of peanut allergy. We aimed to establish the efficacy of OIT for the desensitisation of children with allergy to peanuts.MethodsWe did a randomised controlled crossover trial to compare the efficacy of active OIT (using characterised peanut flour; protein doses of 2–800 mg/day) with control (peanut avoidance, the present standard of care) at the NIHR/Wellcome Trust Cambridge Clinical Research Facility (Cambridge, UK). Randomisation (1:1) was by use of an audited online system; group allocation was not masked. Eligible participants were aged 7–16 years with an immediate hypersensitivity reaction after peanut ingestion, positive skin prick test to peanuts, and positive by double-blind placebo-controlled food challenge (DBPCFC). We excluded participants if they had a major chronic illness, if the care provider or a present household member had suspected or diagnosed allergy to peanuts, or if there was an unwillingness or inability to comply with study procedures. Our primary outcome was desensitisation, defined as negative peanut challenge (1400 mg protein in DBPCFC) at 6 months (first phase). Control participants underwent OIT during the second phase, with subsequent DBPCFC. Immunological parameters and disease-specific quality-of-life scores were measured. Analysis was by intention to treat. Fisher's exact test was used to compare the proportion of those with desensitisation to peanut after 6 months between the active and control group at the end of the first phase. This trial is registered with Current Controlled Trials, number ISRCTN62416244.FindingsThe primary outcome, desensitisation, was recorded for 62% (24 of 39 participants; 95% CI 45–78) in the active group and none of the control group after the first phase (0 of 46; 95% CI 0–9; p<0·001). 84% (95% CI 70–93) of the active group tolerated daily ingestion of 800 mg protein (equivalent to roughly five peanuts). Median increase in peanut threshold after OIT was 1345 mg (range 45–1400; p<0·001) or 25·5 times (range 1·82–280; p<0·001). After the second phase, 54% (95% CI 35–72) tolerated 1400 mg challenge (equivalent to roughly ten peanuts) and 91% (79–98) tolerated daily ingestion of 800 mg protein. Quality-of-life scores improved (decreased) after OIT (median change −1·61; p<0·001). Side-effects were mild in most participants. Gastrointestinal symptoms were, collectively, most common (31 participants with nausea, 31 with vomiting, and one with diarrhoea), then oral pruritus after 6·3% of doses (76 participants) and wheeze after 0·41% of doses (21 participants). Intramuscular adrenaline was used after 0·01% of doses (one participant).InterpretationOIT successfully induced desensitisation in most children within the study population with peanut allergy of any severity, with a clinically meaningful increase in peanut threshold. Quality of life improved after intervention and there was a good safety profile. Immunological changes corresponded with clinical desensitisation. Further studies in wider populations are recommended; peanut OIT should not be done in non-specialist settings, but it is effective and well tolerated in the studied age group.FundingMRC-NIHR partnership

Antimicrobial, antioxidant, and cytotoxic activities of Bixa orellana Linn

Bixa orellana Linn., commonly known as "lipstick plant", is used in folk medicines to treat infections of microbial origin as well as coloring agents in food stuffs in the LDCs like Bangladesh. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the warm water extract of leaves of B. orellana were evaluated against 25 multidrug resistant (MDR) clinical isolates and 6 food-borne pathogens using the micro-dilution broth method modified to comply with the NCCLS standards. The total phenolic content and antioxidant capacity of warm water, ethanol, and methanol extracts of the seeds and leaves of B. orellana were also evaluated. The brine shrimp lethality assay was conducted to assess the toxicity of the extracts. Except Pseudomonas spp., all the MDR isolates and food-borne pathogens tested were susceptible to the warm water extract of the leaves. The MIC and MBC ranged between 8-256 μg/mL and 16 - 256 μg/mL, respectively. Among the test organisms, Streptococcus spp. and Shigella dysenteriae-1 MJ-84 showed highest susceptibility while Escherichia coli exhibited moderate susceptibility to warm water extract of the leaves. The highest total phenolic content (99.99 mg of GAE/g of extractives) and antioxidant capacity (IC50 value 13 μg/mL) were observed in ethanolic extract of seeds of B. orellana, whereas the IC50 of the reference standard BHT (tert-butyl-1-hydroxytoluene) was 59.2 μg/mL. On the other hand, in the brine shrimp lethality bioassay the methanolic extract of the seeds of B. orellana demonstrated strong cytotoxic activity with IC50 value of 19.3 μg/mL. These results suggest that the extracts of B. orellana possess bioactive compoundsColegio de Farmacéuticos de la Provincia de Buenos Aire

IgG4 inhibits peanut-induced basophil and mast cell activation in peanut-tolerant children sensitized to peanut major allergens

BackgroundMost children with detectable peanut-specific IgE (P-sIgE) are not allergic to peanut. We addressed 2 non–mutually exclusive hypotheses for the discrepancy between allergy and sensitization: (1) differences in P-sIgE levels between children with peanut allergy (PA) and peanut-sensitized but tolerant (PS) children and (2) the presence of an IgE inhibitor, such as peanut-specific IgG4 (P-sIgG4), in PS patients.MethodsTwo hundred twenty-eight children (108 patients with PA, 77 PS patients, and 43 nonsensitized nonallergic subjects) were studied. Levels of specific IgE and IgG4 to peanut and its components were determined. IgE-stripped basophils or a mast cell line were used in passive sensitization activation and inhibition assays. Plasma of PS subjects and patients submitted to peanut oral immunotherapy (POIT) were depleted of IgG4 and retested in inhibition assays.ResultsBasophils and mast cells sensitized with plasma from patients with PA but not PS patients showed dose-dependent activation in response to peanut. Levels of sIgE to peanut and its components could only partially explain differences in clinical reactivity between patients with PA and PS patients. P-sIgG4 levels (P = .023) and P-sIgG4/P-sIgE (P < .001), Ara h 1–sIgG4/Ara h 1–sIgE (P = .050), Ara h 2–sIgG4/Ara h 2–sIgE (P = .004), and Ara h 3–sIgG4/Ara h 3–sIgE (P = .016) ratios were greater in PS children compared with those in children with PA. Peanut-induced activation was inhibited in the presence of plasma from PS children with detectable P-sIgG4 levels and POIT but not from nonsensitized nonallergic children. Depletion of IgG4 from plasma of children with PS (and POIT) sensitized to Ara h 1 to Ara h 3 partially restored peanut-induced mast cell activation (P = .007).ConclusionsDifferences in sIgE levels and allergen specificity could not justify the clinical phenotype in all children with PA and PS children. Blocking IgG4 antibodies provide an additional explanation for the absence of clinical reactivity in PS patients sensitized to major peanut allergens

Defining the spatial distribution of extracellular adenosine revealed a myeloid-dependent 1 immunosuppressive microenvironment in pancreatic ductal adenocarcinoma

Synopsis: The clinical development of anti-CD73 antibodies has demonstrated their utility, but 59 the mechanism for this effect has not been fully elucidated. We now show that targeting the 60 adenosine pathway reduces extracellular adenosine in myeloid rich, hypoxic areas of pancreatic 61 ductal adenocarcinoma, abrogating the pro-tumorigenic, immunosuppressive 62 microenvironment and improving the efficacy of anti-tumour interventions

Molecular docking and dynamics simulation study of medicinal fungi derived secondary metabolites as potential inhibitor for COVID-19 treatment

The severity of COVID-19, lack of specific treatment, and controversies on the vaccine's efficacy demand the development of new drugs against SARS-CoV-2. Fungi produce various metabolites with diverse molecular structures that have emerged as promising antiviral drug candidates. Therefore, the present study aimed to investigate medicinal fungi derived secondary metabolites as potential inhibitors of 3 different targets associated with viral entry (human TMPRSS2) and replication (main and papain-like protease) through molecular docking and dynamic simulation studies. Based on our findings, we identified Phelligridin E, Lepiotaprocerine G, and Inoscavin A as the potential blockers of SARS-CoV-2 main protease, papain-like protease, and human TMPRSS2, respectively. These compounds strongly interacted with their corresponding target, passed Lipinski Rule's and had acceptable ADMET properties. Drug-protein complexes showed good stability during MD simulation. Estimation of binding free energy using the MM-GBSA method validated the inhibitor potential of identified compounds. Taken together, we believe that further in vitro and in vivo investigations on our proposed molecules may contribute to expanding the therapeutic arsenal in our fight against COVID-19

Study of induction of Tolerance to Oral Peanut: a randomised controlled trial of desensitisation using peanut oral immunotherapy in children (STOP II)

Background: Peanut allergy is a common disease that causes severe and fatal food allergic reactions. Currently, the best treatment is avoidance as repeated reactions can occur. Quality of life (QoL) is reduced by fear of severe reactions and social limitations. Oral immunotherapy (OIT) is a novel treatment that may be an effective treatment for peanut allergy. Objectives: To determine the efficacy of peanut OIT in children. Design: A phase 2 randomised, controlled, crossover trial (open label). Setting: Single UK centre study. Participants: Children aged 7–15 years with peanut allergy diagnosed by double-blind, placebo-controlled food challenge (DBPCFC). No children were excluded because of anaphylaxis or asthma. Interventions: Daily immunotherapy (2 mg, 5 mg, 12.5 mg, 25 mg, 50 mg, 100 mg, 200 mg, 400 mg and 800 mg of peanut protein) was administered as peanut flour (containing 50% peanut protein). Doses were increased at 2-weekly intervals to a maintenance dose of 800 mg of protein. The control group underwent peanut avoidance for 6 months during phase 1. Main outcome measure: A peanut DBPCFC up to 1400 mg of peanut protein was performed in both groups at 6 months. The highest amount of peanut tolerated was the main outcome measure. Randomisation: Randomised by online audited system to active or control group (1 : 1). Blinding: The intervention arm allocation was not blinded. Methods: We assigned 99 participants aged 7–16 years with peanut allergy of all severities to active OIT or control (peanut avoidance/current standard of care). The primary outcome was desensitisation, defined as negative peanut challenge (1400 mg of protein DBPCFC) at 6 months (phase 1). Control participants underwent OIT during phase 2, followed by DBPCFC. Immunological parameters and disease-specific QoL scores were measured. Results: The primary outcome, desensitisation, was observed in 62% (24/39) of the active group and none (0/46) of the control group after phase 1 [95% confidence interval (CI) 45% to 78% vs. 0% to 9%; p < 0.001]; 84% (95% CI 70% to 93%) of the active group tolerated daily ingestion of 800 mg of protein (≈ five peanuts). Median increase in peanut threshold after OIT was 1345 mg (range 45–1400 mg; p < 0.001) or 2.5-fold (range 1.82–280-fold; p < 0.001). After phase 2, 54% (95% CI 35% to 72%) tolerated a 1400-mg challenge (≈ 10 peanuts) and 91% (95% CI 79% to 98%) tolerated a daily ingestion of 800 mg of protein. QoL scores improved (decreased) after OIT (median change –1.61; p < 0.001). Side effects were mostly mild with gastrointestinal symptoms being the most common: oral pruritus occurred after 6.3% of doses, wheeze occurred after 0.41% of doses (one-fifth of participants) and intramuscular epinephrine was required after 0.01% of doses (one participant). Conclusion: In children with peanut allergy of any severity, OIT successfully induced desensitisation in the majority, with a clinically meaningful increase in peanut threshold. QoL improved after intervention and there was a good safety profile. Immunological changes reflected clinical desensitisation. Peanut OIT should not be undertaken in non-specialist settings. Future work will include a phase 3 confirmatory study and studies of long-term tolerance; similar studies of other allergens are also required. Trial registration: Current Controlled Trials ISRCTN62416244. Funding: This project was awarded by the Efficacy and Mechanism Evaluation programme and is funded by the Medical Research Council (MRC) and managed by the National Institute for Health Research (NIHR) on behalf of the MRC–NIHR partnership, and jointly sponsored by the University of Cambridge and Addenbrooke’s Hospital [Cambridge University Hospital Foundation Trust (RD authorisation A091686)]. The project will be published in full in Efficacy and Mechanism Evaluation; Vol. 1, No. 4. See the NIHR Journals Library website for further project information

Transmission of Infectious Vibrio cholerae Through Drinking Water among the Household Contacts of Cholera Patients (CHoBI7 Trial)

Recurrent cholera causes significant morbidity and mortality among the growing population of Dhaka, the capital city of Bangladesh. Previous studies have demonstrated that household contacts of cholera patients are at >100 times higher risk of cholera during the week after the presentation of the index patient. Our prospective study investigated the mode of transmission of Vibrio cholerae, the cause of cholera, in the households of cholera patients in Dhaka city. Of total 420 rectal swab samples analyzed from 84 household contacts and 330 water samples collected from 33 households, V. cholerae was isolated from 20%(17/84) of household contacts, 18%(6/33) of stored drinking water, and 27%(9/33) of source water samples. Phenotypic and molecular analyses results confirmed the V. cholerae isolates to be toxigenic and belonging to serogroup O1 biotype El Tor (ET) possessing cholera toxin of classical biotype (altered ET). Phylogenetic analysis by pulsed-field gel electrophoresis (PFGE) showed the V. cholerae isolates to be clonally linked, as >95% similarity was confirmed by sub-clustering patterns in the PFGE (NotI)-based dendrogram. Mapping results showed cholera patients to be widely distributed across 25 police stations with the highest incidence in households near the major rivers and polluted water bodies. The data presented on the transmission of infectious V. cholerae within the household contacts of cholera patients through drinking water underscores the need for safe water to prevent spread of cholera and related deaths in Dhaka city

Interleukin-4 can induce interleukin-4 production in dendritic cells

The presence of interleukin-4 (IL-4) during the generation of dendritic cells (DC) from precursor cells results in measurable increases of IL-12 in supernatants but IL-4 secretion has not been reported. However, DC have IL-4 receptors and are able to make IL-4. We therefore sought evidence for autocrine effects of IL-4 on DC. IL-4 gene expression was low in DC generated from bone-marrow stem cells in the presence of granulocyte–macrophage colony-stimulating factor but was up-regulated by exposure of the developing DC to IL-4. Exposure to IL-4 also induced intracellular IL-4 production in DC. The intracellular IL-4 induced in the presence of IL-4 was increased following further DC maturation with tumour necrosis factor-α. By contrast, in supernatants of DC, IL-4 was rarely detected and only at late culture periods. However, after exposure of DC to IL-4, cell-bound IL-4 was detected transiently, which suggested binding and internalization of the cytokine. Binding via IL-4 receptor-α was indicated from phosphorylation of the signal transducer and activator of transcription (STAT) protein 6, which is known to mediate IL-4 function. Cytokine persisting within the supernatants of the cells may therefore be unrepresentative of the actual production and function of IL-4 in the cells; IL-4 may be produced in DC in response to exposure to IL-4 but may then be lost from the supernatants during cell binding and activation of the cells

Defining the spatial distribution of extracellular adenosine revealed a myeloid-dependent immunosuppressive microenvironment in pancreatic ductal adenocarcinoma

Peer reviewed: TrueBackground: The prognosis for patients with pancreatic ductal adenocarcinoma (PDAC) remains extremely poor. It has been suggested that the adenosine pathway contributes to the ability of PDAC to evade the immune system and hence, its resistance to immuno-oncology therapies (IOT), by generating extracellular adenosine (eAdo). Methods: Using genetically engineered allograft models of PDAC in syngeneic mice with defined and different immune infiltration and response to IOT and autochthonous tumors in KPC mice we investigated the impact of the adenosine pathway on the PDAC tumor microenvironment (TME). Flow cytometry and imaging mass cytometry (IMC) were used to characterize the subpopulation frequency and spatial distribution of tumor-infiltrating immune cells. Mass spectrometry imaging (MSI) was used to visualize adenosine compartmentalization in the PDAC tumors. RNA sequencing was used to evaluate the influence of the adenosine pathway on the shaping of the immune milieu and correlate our findings to published data sets in human PDAC. Results: We demonstrated high expression of adenosine pathway components in tumor-infiltrating immune cells (particularly myeloid populations) in the murine models. MSI demonstrated that extracellular adenosine distribution is heterogeneous in tumors, with high concentrations in peri-necrotic, hypoxic regions, associated with rich myeloid infiltration, demonstrated using IMC. Protumorigenic M2 macrophages express high levels of the Adora2a receptor; particularly in the IOT resistant model. Blocking the in vivo formation and function of eAdo (Adoi), using a combination of anti-CD73 antibody and an Adora2a inhibitor slowed tumor growth and reduced metastatic burden. Additionally, blocking the adenosine pathway improved the efficacy of combinations of cytotoxic agents or immunotherapy. Adoi remodeled the TME, by reducing the infiltration of M2 macrophages and regulatory T cells. RNA sequencing analysis showed that genes related to immune modulation, hypoxia and tumor stroma were downregulated following Adoi and a specific adenosine signature derived from this is associated with a poorer prognosis in patients with PDAC. Conclusions: The formation of eAdo promotes the development of the immunosuppressive TME in PDAC, contributing to its resistance to conventional and novel therapies. Therefore, inhibition of the adenosine pathway may represent a strategy to modulate the PDAC immune milieu and improve therapy response in patients with PDAC