Allergy & Immunology

Asthma in Pregnancy: Control Determines Obstetric Risk

This review highlights that uncontrolled, not merely diagnosed, asthma drives adverse outcomes in pregnancy. Compared with controlled disease, uncontrolled asthma increases preterm birth, hypertensive disorders, and impaired fetal growth or small-for-gestational-age neonates. Proposed mechanisms include airway inflammation, oxidative stress, placental dysfunction, and maternal hypoxemia in a pregnancy-related Th2-skewed milieu. Modifiable contributors such as viral infections, pollution, indoor exposures, obesity, rhinitis, GERD, and sleep apnea are emphasized as management targets. Guidance aligns with international asthma guidelines, stressing proactive monitoring and continuation or step-up of controller therapy through gestation. 1

Severe Asthma Patients Accumulate High Steroid Burden Before Biologics

This nationwide Danish cohort quantified 25-year corticosteroid exposure in 542 severe asthma patients initiating biologics. Over a median 16-year period, patients accumulated a median 17.1 g total corticosteroids, including 7.2 g systemic prednisolone equivalents. More than half experienced greater systemic than inhaled corticosteroid exposure, reflecting heavy reliance on oral steroids. Two-thirds had systemic exposure ≥5 mg prednisolone equivalents daily in the year before biologic initiation. Notably, about 72% of total corticosteroid exposure occurred before the first specialist visit, especially in chronic severe asthma. The authors argue that reducing corticosteroid exposure must be a key priority when managing severe asthma. 2

Basophil Activation Model Identifies RSAD2 as Candidate Omalizumab Response Biomarker

Researchers established an in vitro basophil activation and degradation assay using omalizumab-pretreated leukocytes from asthmatic children and adolescents. Basophils were then exposed to patient-specific allergens to characterize individual omalizumab responses. Basophil RNA sequencing revealed differentially expressed genes between better and poor or non-responders, predominantly related to antiviral defense. Low RSAD2 expression correlated with poor in vitro omalizumab response and was confirmed in an independent cohort. The authors propose this basophil model and RSAD2 expression as tools to explore predictive biomarkers for omalizumab responsiveness. 3

Topical Acacia Gum Modulates Staphylococcal Dysbiosis in Atopic Dermatitis Models

This study tested acacia gum as a topical prebiotic to correct Staphylococcus aureus–dominated dysbiosis in atopic dermatitis. In coculture, acacia gum selectively promoted Staphylococcus epidermidis while suppressing S. aureus via direct antibacterial and commensal-mediated effects. It upregulated S. epidermidis glutamyl endopeptidase, disrupted S. aureus biofilms, and reduced intracellular persistence in macrophages. Acacia gum also dampened keratinocyte and macrophage activation by downregulating proinflammatory cytokines and chemokines. In an AD-like mouse model, topical acacia gum reduced S. aureus burden, improved microbial diversity, partially restored barrier integrity, and decreased inflammation without toxicity. 4