ABSTRACT Bioassays offer functional readouts of immune responses through specific biomarkers, providing mechanistic insight beyond conventional serology. By capturing cellular activation, tissue‐level changes, and molecular signaling, they hold promise for refining allergy diagnosis, risk stratification, and treatment monitoring, contributing to precision medicine. This review summarizes the current landscape of three allergy‐relevant bioassays: basophil activation test, histology, and molecular biology‐based assays. We discuss their underlying principles, clinical utilities as well as methodological and translational challenges and translational barriers. Attention is given to unmet needs such as assay standardization, reproducibility, and integration into clinical workflows. Finally, we outline future directions for research and clinical implementation, emphasizing the potential of bioassays to refine personalized management of allergic disorders. This position paper clearly distinguishes between descriptive summaries of the available evidence and the potential applicability recommendations of the EAACI Task Force, thereby enhancing clarity and interpretability for clinicians and researchers.
ABSTRACT Background Mitochondrial DNA copy number (mtDNA‐CN), a marker associated with mitochondrial function and cellular health, has been implicated in several chronic inflammatory diseases. Atopic dermatitis is a common chronic inflammatory skin disorder, yet the relationship between mtDNA‐CN and childhood atopic dermatitis remains unclear. This study aimed to investigate the association between mtDNA‐CN and atopic dermatitis in a population‐based cohort of school‐aged children. Methods We included 1329 singleton children (56.4% boys; mean age ± standard deviation: 6.5 ± 0.5 years) from the Longitudinal Investigation of Global Health in Taiwanese Schoolchildren (LIGHTS) cohort. Genomic DNA was extracted from peripheral blood, and mtDNA‐CN was quantified by real‐time quantitative polymerase chain reaction. Multivariable logistic regression models were applied. Results Among the 1329 children, 328 (24.7%) children had physician‐diagnosed atopic dermatitis. Mean mtDNA‐CN was lower in children with atopic dermatitis than in those without (289.62 ± 102.06 vs. 299.47 ± 91.90; p = 0.03). Each one‐unit increase in log‐transformed mtDNA‐CN was associated with 28% lower odds of atopic dermatitis after adjustment for potential confounders (adjusted odds ratio: 0.72; 95% confidence interval: 0.54–0.96). Subgroup analyses showed that this inverse association was more pronounced among children breastfed for ≥ 3 months and those with a birth weight ≥ 2500 g. Conclusion This study provides novel evidence of an inverse association between mtDNA‐CN and atopic dermatitis in children. Further longitudinal and mechanistic studies are warranted to confirm these findings and to evaluate the potential utility of mtDNA‐CN as a biomarker for atopic dermatitis.
ABSTRACT Background Biologic therapies can control severe asthma and may modify its natural history beyond symptom control. However, step‐down is not standardized, and its safety has not been clearly established. Methods This single‐center retrospective cohort study reviewed adults with severe asthma on biologics (January 2019–May 2024). Step‐down strategies (discontinuation of add‐on therapy and/or inhaled corticosteroid [ICS] dose reduction) were described, success rates calculated, and clinical characteristics compared between groups with and without step‐down. Results Fifty‐one patients were included, of whom 10 (19.6%) received omalizumab, 34 (66.7%) mepolizumab, and 7 (13.7%) benralizumab. After excluding 6 patients unsuitable for step‐down assessment, 45 patients were compared. Step‐down was attempted in 21 of these (46.7%) and succeeded in 17 (81.0%), defined as no systemic corticosteroid use, emergency visit, loss of control (ACT < 20), or exacerbation through the last visit. The most frequent interventions were ICS dose reduction ( n = 7, 33.3%) and montelukast discontinuation ( n = 7, 33.3%). Biologics had been received for a mean of 42.6 ± 14.0 months, and the reduced regimen was maintained for 8.15 ± 5.23 months. Compared with the non–step‐down group, the step‐down group had a higher proportion of males ( p = 0.005) and longer follow‐up ( p = 0.007). Conclusion In this real‐world cohort, step‐down was feasible and appeared safe, with most patients maintaining the reduced regimen without deterioration in control or exacerbations. These findings support supervised treatment minimization in carefully selected, well‐controlled patients, adding real‐world evidence to a limited literature.
ABSTRACT Background/Aim Data on the course of nonsteroidal anti‐inflammatory drug (NSAID) hypersensitivity in NSAID‐exacerbated cutaneous disease (NECD) are limited. We aimed to evaluate NSAID tolerance in NECD patients with well‐controlled urticaria. Methods 142 patients with well‐controlled urticaria [Urticaria Control Test (UCT) ≥ 12; Urticaria Activity Score over 7 days (UAS7) ≤ 6] underwent a single blind, placebo‐controlled acetylsalicylic acid (ASA) provocation test. Patients were categorized into three groups based on their treatment; omalizumab, antihistamine, or no treatment. Results The median age of the patients was 40 years (IQR 31.5–52), and 79.6% were female. The median disease duration of chronic spontaneous urticaria (CSU) was 4 years (IQR 2–8). The ASA provocation test was positive in 29 patients (20.4%). Positive patients had lower UCT and higher UAS7 scores (both p < 0.001). ASA provocation test positivity was more common in the antihistamine group compared to both the omalizumab ( p = 0.001) and untreated groups ( p < 0.001). ROC analysis showed that UCT ≤ 15 predicted ASA provocation test positivity with 72.4% sensitivity and 83.2% specificity, while UAS7 ≥ 4 predicted positivity with 72.4% sensitivity and 86.7% specificity. The negative predictive values (NPV) were 92.2% and 92.5%, respectively. Conclusion To our knowledge, this is the first study to demonstrate, in a large NECD cohort, that NSAID tolerance can be achieved in patients with well‐controlled urticaria under different treatment modalities, regardless of complete remission status. UCT ≤ 15 and UAS7 ≥ 4 are useful clinical predictors of provocation test positivity and, given their high NPVs, are particularly valuable for excluding positivity.
