This Week in Allergy & Immunology — Sep 13, 2026

Welcome to This Week in Allergy and Immunology. This week we're covering 10 notable papers spanning asthma prevention and new airway therapeutics, the social and environmental drivers of asthma morbidity, and practical diagnostics in food and venom allergy. Let's dive in.

We start with a big, clean negative result. In The Lancet, Morgan and colleagues report the ORBEX trial, which asked whether the oral bacterial lysate OM-85 could prevent wheezing lower respiratory illness in young children at high risk of asthma [1]. Eight hundred and twenty-two children aged six to eighteen months, selected for atopic dermatitis, parental asthma, or an affected older sibling, were randomised to OM-85 or placebo, taken ten days a month for two years, then followed for a further three years off drug. The primary outcome was time to first wheezing lower respiratory illness during that off-drug observation period. There was no benefit. About one in five children in each group wheezed, and if anything the curve favoured placebo numerically, though the difference was not statistically significant. Fevers, coughs and colds were equally common in both arms. The authors' conclusion is unambiguous, and worth carrying into clinic conversations with parents who have read about immunostimulants online: bacterial lysates are not efficacious for the primary prevention of asthma-like symptoms in the preschool years. That closes a question that has been open for the best part of a decade.

At the other end of the development pipeline, Nature Medicine published the first-in-human experience with ARO-RAGE, an inhaled small interfering RNA that silences the receptor for advanced glycation end products in lung epithelium [2]. RAGE is abundantly expressed on alveolar type-one cells and amplifies innate inflammation in both asthma and chronic obstructive pulmonary disease, so an inhaled, lung-restricted knockdown is an appealing concept. In a phase one, two-a randomised placebo-controlled study of fifty-eight healthy volunteers and nineteen patients with asthma, the drug was safe and well tolerated, with no clinically relevant changes in chest radiographs, spirometry or systemic inflammatory markers. Plasma drug levels were low, consistent with the drug staying where it was inhaled, and soluble RAGE fell in both serum and bronchoalveolar lavage in a dose-responsive way, confirming genuine pulmonary target engagement. This is a safety and pharmacology readout, not an efficacy trial — there are no exacerbation or lung function outcomes here — but it establishes that inhaled siRNA can reach and silence a target in the airway epithelium, which opens a new therapeutic modality for our specialty.

Sitting between those two is a monoclonal antibody story from Allergy. Wechsler and colleagues report exploratory, largely post hoc subgroup analyses from the phase two-b trial of rademikibart, an interleukin-4 receptor alpha targeting antibody, in moderate-to-severe uncontrolled asthma [3]. Slicing the population by baseline eosinophils and exhaled nitric oxide, benefit tracked type two biomarkers closely. In patients with both eosinophils at or above three hundred cells per microlitre and exhaled nitric oxide at or above twenty-five parts per billion, pre-bronchodilator lung function improved by more than four hundred millilitres over placebo within a single week after the loading dose, and that gain was sustained and slightly larger at twenty-four weeks on the three hundred milligram dose. In patients with eosinophils between one hundred and fifty and three hundred, the gain was closer to a hundred and sixty millilitres. Exacerbations fell by at least sixty-three percent across every subgroup examined, and no eosinophilia was reported as an adverse event. These are hypothesis-generating analyses in small subgroups, so treat the effect sizes as directional rather than definitive — but the message is the familiar one, reinforced: the higher the baseline type two signal, the bigger the return from blocking it.

The second theme is who actually gets asthma, and who suffers most from it — and here two papers from different journals converge. In Allergy, Lee and colleagues analysed more than eight million adults in the Korean national health insurance database, linked to fine-resolution estimates of long-term particulate exposure [4]. Each ten microgram per cubic metre increment in fine particulate matter was associated with roughly a third higher risk of new-onset asthma, with a similar signal for coarse particulate. The more striking finding is the gradient. Risk was lowest in younger adults without medical aid living rurally, and highest — nearly double — in older adults receiving medical aid and living in cities. Air pollution is not an equal-opportunity exposure; poverty, urban residence and age compound it.

That compounding continues once asthma is established. In Annals of Allergy, Asthma and Immunology, Lian and colleagues examined household food hardship and asthma morbidity in United States children, using two independent national surveys covering more than twenty-three thousand children in one and roughly two thousand eight hundred in the other [5]. Children in food-insecure households had about a quarter higher prevalence of caregiver-reported moderate or severe asthma, roughly thirty percent more asthma attacks, and about thirty percent more asthma-related emergency or urgent care visits. At the highest level of hardship, acute care use was close to double. In absolute terms that is around twelve additional percentage points of attacks — not a marginal signal. These are cross-sectional, caregiver-reported associations and cannot prove causation, but taken with the Korean pollution data they make a practical point: a screening question about food insecurity may explain more about a child's uncontrolled asthma than another step up in inhaled corticosteroid dose.

Our third theme is diagnostics and day-to-day allergy practice. In Clinical and Experimental Allergy, Faihs and colleagues studied fifty-four adults with challenge-confirmed wheat allergy dependent on augmentation factors, alongside twenty-one tolerant controls, testing specific IgE against nineteen recombinant wheat proteins [6]. Specific IgE to alpha and beta gliadin was present in just over half of the patients and in none of the controls — complete specificity, with a suggested cut-off of zero point two two kilounits per litre. Reactivity to non-gluten wheat proteins was limited and largely explained by cross-reactive carbohydrate determinants and grass pollen sensitisation, which is a useful reminder when interpreting broad wheat component panels. The practical upshot is that adding alpha and beta gliadin to omega-five gliadin sharpens diagnostic specificity in this population.

Staying with food, International Archives of Allergy and Immunology published a twenty-three year Danish single-centre series of oral food challenges to shrimp in three hundred and twenty-four patients [7]. Only about twelve percent of suspected cases were confirmed, and confirmation was far more likely in children and adolescents than in adults — roughly twenty-three percent versus eight percent. Among those who reacted, one in ten had anaphylaxis, and the median eliciting dose was close to nineteen grams. House dust mite sensitisation was substantially more common in the shrimp-allergic group, and the authors found that a response to shrimp stronger than the response to mite predicted a positive challenge. The headline for practice is that most patients labelled shrimp-allergic on testing alone are not, and mite cross-reactivity is a major reason why.

Two more papers round out the practice theme. Also in Allergy, Sousa-Pinto and colleagues used the MASK-air mobile health app to compare nearly two thousand seven hundred pollen-season weeks in which patients took a single rhinitis medication every day versus weeks in which they took it on demand [8]. For intranasal corticosteroids and for fixed antihistamine-corticosteroid combinations, treatment satisfaction was no different between the two patterns, and for symptom control the results either showed no difference or actually favoured as-needed use. This is observational, with all the confounding by indication that implies — better weeks may simply require less medication — but it argues against reflexively scolding patients who dose to symptoms. And in International Archives of Allergy and Immunology, Harman and colleagues compared subcutaneous aeroallergen immunotherapy with venom immunotherapy across more than two thousand two hundred injections in a single centre [9]. Systemic reactions were about ten times more frequent at patient level with venom immunotherapy, and at injection level the difference was roughly thirtyfold — about ninety-five per thousand venom injections versus three per thousand aeroallergen injections — with most venom systemic reactions reaching higher severity grades. Despite that, documented discontinuation was numerically lower with venom immunotherapy, though that difference was not statistically significant in this small sample of twenty-eight venom patients.

Finally, a conceptual piece worth reading if you prescribe biologics. In Allergy, Jiménez-Saiz and colleagues review the evolutionary origins and homeostatic functions of type two immunity, arguing it is not merely an anti-helminth and pro-allergy programme but also a tissue protection and repair system [10]. Their question is a fair one as our biologics multiply: what are the long-term consequences of sustained type two blockade?

If you only have time for one paper this week, make it the ORBEX trial in The Lancet [1]. It is a large, rigorously conducted primary prevention trial with a clearly negative result, and it should change what you tell families asking about bacterial lysates for their high-risk toddler.

Here are the key takeaways from this week in Allergy and Immunology. First, OM-85 does not prevent preschool wheezing in high-risk children — stop recommending it for that indication. Second, the type two biomarker rule holds: rademikibart's largest gains were in patients with both high eosinophils and high exhaled nitric oxide, and inhaled siRNA against RAGE has now shown safe lung target engagement in humans, though efficacy is unproven. Third, particulate exposure and household food insecurity both track with asthma incidence and morbidity, and their effects concentrate in the same disadvantaged patients — ask about food hardship in uncontrolled paediatric asthma. Fourth, in diagnostics, alpha and beta gliadin specific IgE adds specificity in augmentation-dependent wheat allergy, and most suspected shrimp allergy is not confirmed on challenge, largely because of mite cross-reactivity. And fifth, venom immunotherapy carries a markedly higher systemic reaction rate per injection than aeroallergen immunotherapy — counsel and staff accordingly.

That's your roundup for This Week in Allergy and Immunology. The full transcript and references are available on the episode page in your AudioScholar library. This is an AI-curated summary — for clinical decisions, always consult primary sources and current guidelines. See you next week.

If this weekly briefing is useful, follow the show in your podcast app so new episodes arrive automatically. And a quick rating on Apple Podcasts or Spotify helps other physicians discover the show.

This is an automated summary generated by artificial intelligence, which can make mistakes. Always review the original source materials.