This Week in Allergy & Immunology — Aug 28, 2026

Welcome to This Week in Allergy and Immunology. This week we're covering 10 notable papers spanning new therapeutic mechanisms in atopic disease, biomarkers and risk stratification across asthma and aspergillosis, an unexpected transfusion hazard in alpha-gal country, and a hard look at the trustworthiness of the evidence base we all rely on. Let's dive in.

We start with the biggest therapeutic news, published in The Lancet. Rezpegaldesleukin is an interleukin-2 receptor agonist designed to selectively expand regulatory T cells — a fundamentally different approach from blocking a type 2 cytokine. In REZOLVE-AD, a phase 2b, double-blind, placebo-controlled trial across 107 sites in ten countries, Silverberg and colleagues randomised 398 biologic-naive adults with moderate-to-severe atopic dermatitis to one of three subcutaneous dosing regimens or placebo for a sixteen-week induction period [1]. All three active arms met the primary endpoint, with dose-dependent improvement in the Eczema Area and Severity Index. The highest dose, 24 micrograms per kilogram every two weeks, produced a mean reduction of about 61 percent from baseline, compared with roughly 31 percent on placebo — a treatment difference of about 30 percentage points. The every-four-week regimen still beat placebo by about 22 percentage points. The point of interest here is mechanistic: rather than suppressing effector inflammation, this drug attempts to restore regulatory tolerance, which raises the prospect of durable off-treatment benefit. That question is not answered by a sixteen-week induction readout, and the placebo response was substantial, so temper expectations until the maintenance data and phase 3 arrive.

The second theme is biomarkers and risk stratification — how we decide who is in trouble and when. In the Journal of Allergy and Clinical Immunology: In Practice, Muthu and colleagues prospectively followed 122 adults with allergic bronchopulmonary aspergillosis, measuring total IgE alongside crude and recombinant Aspergillus fumigatus-specific IgE at baseline, two months and four months [3]. Total IgE and all three recombinant antigen-specific IgEs fell significantly with treatment, while crude Aspergillus IgE did not budge. A twenty percent or greater decline was seen more often with at least one recombinant marker than with total IgE — over ninety percent versus about three quarters of patients at two months. Most striking, among the fifteen patients who exacerbated over twelve months, recombinant f4-specific IgE rose in every single case, compared with twelve of fifteen for total IgE. That is a small event count and needs multicentre confirmation, but it suggests a more specific exacerbation signal than the total IgE we currently anchor on. On the asthma side, Annals of Allergy, Asthma and Immunology reports on the Pediatric Asthma Impairment and Risk Questionnaire, an eight-item yes-no tool for children aged five to eleven. Bachelier and colleagues followed 313 children for three months, during which about a fifth of the cohort had at least one exacerbation [9]. Each one-point rise in the baseline score raised the odds of a subsequent exacerbation by roughly a third, and children categorised as very poorly controlled had close to four times the odds of exacerbating compared with well-controlled children. This is a point-of-care instrument that takes a minute to complete and gives you genuine forward-looking risk, not just a snapshot of symptoms.

Staying with asthma, two pieces in the same journals address what we do with that risk information. Szefler, writing in the Journal of Allergy and Clinical Immunology: In Practice, argues for corticosteroid stewardship as a formal discipline [8]. The premise is that after twenty years of asthma biologics, the clearest shared benefit across all of them is reduced exacerbations and therefore reduced systemic steroid exposure — and that specialists should now lead structured programmes with patient education materials, shared decision-making prototypes, and eventually health-system and payer partnership, in the same way antimicrobial stewardship evolved. Complementing that, Allergy publishes a conceptual framework from Gangemi and colleagues on airway remodelling in severe asthma [2]. They ask whether there is a time-sensitive window in which biologics can alter structural airway trajectories rather than just symptoms, and propose linking mechanism to biomarker to a remodelling readout — biopsy indices and quantitative imaging — to a timing decision, supported by causal artificial intelligence methods and data from smart inhalers and wearables. This is a roadmap, not evidence; nothing here changes prescribing today, but it does frame the question of whether we are treating too late.

Now the paper most likely to change something in your hospital. JAMA Internal Medicine reports an international retrospective cohort of more than 558,000 platelet and plasma transfusions at 40 sites in five countries, testing whether alpha-gal syndrome can be transmitted through the blood supply [5]. The hypothesis was that recipients with blood type O — who therefore carry no B antigen tolerance — might react to B or AB units carrying alpha-gal-bearing material, but only where alpha-gal syndrome is endemic. Allergic transfusion reactions occurred in about three in a thousand transfusions overall. In the United States high-prevalence cluster of nine sites, type O recipients given B or AB units had roughly four times the risk of an allergic transfusion reaction compared with type O recipients given O units, and for moderate-to-severe reactions to B units specifically the risk was around nine-fold. In the low-prevalence cluster, no excess was detected in the primary analysis, and no signal consistent with this entity appeared outside the United States. That geographic specificity is exactly what you would predict if the mechanism is real. Kaufman and colleagues are appropriately cautious — this is retrospective and they call the evidence provocative rather than definitive — but if you practise in a tick-endemic region and you are consulted on a severe platelet or plasma reaction in a type O patient, ABO-matching the product is now a reasonable conversation with your transfusion service.

One more diagnostic reframe, also in the Journal of Allergy and Clinical Immunology: In Practice. The COLD-CE study analysed 364 patients with cold urticaria across eleven international centres and found that a third of them had negative standard cold stimulation testing [4]. These patients were not simply mislabelled: they were younger, had earlier onset, and were independently more likely to have a family history of cold urticaria, concomitant chronic spontaneous urticaria, and to require an obligatory subjective feeling of cold — not merely contact — to develop symptoms. Reassuringly, the test-positive patients were the ones reporting more oropharyngeal angioedema, breathing difficulty and cardiovascular symptoms. The practical message is that a negative ice cube or TempTest does not exclude cold urticaria, and Terhorst-Molawi and colleagues describe a clinically distinct phenotype that we have been under-recognising.

Finally, a theme about the evidence itself. In a commentary in the Journal of Allergy and Clinical Immunology: In Practice, Chu and colleagues report that within eight recent Joint Task Force on Practice Parameters systematic reviews, about 17 percent of trials published between 2021 and 2024 were problematic — implausible data, statistical anomalies, protocol-publication mismatches [6]. In one network meta-analysis of antihistamines for chronic urticaria, nearly four in ten recent trials had to be excluded. They warn that generative artificial intelligence makes superficially credible but fabricated reports easier to produce, and they commit to retrospectively purging affected reviews. A companion paper from Rayner and colleagues gives clinicians a practical guide to judging whether a network meta-analysis is credible, using worked examples from the same guideline programme [7]. Read together, these are a reminder that the certainty ratings attached to our guidelines are only as good as the trials underneath them.

And rounding out the week, Annals of Allergy, Asthma and Immunology reports on IgE deficiency in primary immunodeficiency, using 1,593 patients from the USIDNET registry [10]. Nearly a quarter had an IgE at or below 2 kilounits per litre, rising to about three quarters in ataxia-telangiectasia and a third in common variable immunodeficiency. Those with IgE deficiency had more splenomegaly, neutropenia and thrombocytopenia, and within the common variable immunodeficiency subgroup, nearly three times the odds of malignancy. Infection and sepsis rates were no different. So a very low IgE may flag immune dysregulation rather than infection risk — hypothesis-generating from registry data, but a cheap number you already have on the panel.

If you only have time for one paper this week, make it the transfusion alpha-gal study in JAMA Internal Medicine [5]. It identifies a previously unrecognised and potentially preventable cause of severe transfusion reactions, and allergists in tick-endemic regions are the people who will be asked to make sense of it.

Here are the key takeaways from this week in Allergy and Immunology. First, a regulatory T cell-directed interleukin-2 agonist beat placebo on eczema severity at sixteen weeks in phase 2b — a new mechanism worth watching, but induction data only. Second, in patients with allergic bronchopulmonary aspergillosis, recombinant Aspergillus f4-specific IgE tracked treatment response and rose at every exacerbation, outperforming total IgE in a single-centre cohort. Third, in tick-endemic regions of the United States, type O patients receiving B or AB platelets or plasma had several-fold higher allergic transfusion reaction risk — consider ABO matching after a severe reaction. Fourth, a negative cold stimulation test does not rule out cold urticaria; a third of affected patients test negative and look clinically distinct. And fifth, roughly one in six recent trials in our own guideline systematic reviews were judged problematic — be sceptical of small, unregistered, implausibly clean randomised trials.

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.

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