Determinants of blood eosinophilia in moderate and severe asthmatic patients during childhood: Evidence from the severe asthma molecular phenotype (SAMP) cohort.

BACKGROUND: Asthma is a heterogeneous disease in which the interaction between genetic and environmental factors plays a major role. The significance of blood eosinophil is unclear. The aim of the study was to determine the significance of blood eosinophil count in moderate-to-severe asthmatic children of preschool age and school age. METHODS: This was a prospective cross-sectional study performed from 2011 to 2015 including children from the severe asthma molecular phenotype (SAMP) cohort at Trousseau Hospital (Paris, France). We included children with severe and moderate asthma, or severe and moderate recurrent wheeze, aged from 1 to 15 years at the time of exploration. RESULTS: We analyzed data from 402 children: 248 of preschool age and 154 of school age. Blood eosinophil count third quartile thresholds were 322 and 600 cells/µL for the preschool- and school-age groups, respectively. In multivariate analysis, a blood eosinophil count over this threshold was associated with elevated total IgE (OR = 5.33, P < .01), multiple hospitalizations for asthma attacks (OR = 4.96, P = .03), and a maternal history of asthma (OR = 4.91, P = .01) in preschool children; and with staphylococcal toxin-specific IgE (OR = 2.75, P = .03) in children of school age. Random forest analysis reinforced these results. CONCLUSION: High blood eosinophil count is linked to both atopic features and control of asthma with different parameters associated with these features depending on age.

Two Different Composite Markers Predict Severity and Threshold Dose in Peanut Allergy.

BACKGROUND: Safe and cost-effective biological surrogate markers to evaluate the severity and threshold dose of peanut allergy (PA) reactions during an oral food challenge (OFC) are lacking. OBJECTIVE: To evaluate biological markers associated with the severity and threshold dose of an allergic reaction during an OFC in a population of children with PA. METHODS: Demographic and biological parameters of children with peanut OFC and basophil activation test (BAT) results were collected. Patients were stratified into 2 severity groups (mild-to-moderate and severe) and 2 cumulative threshold dose groups: low (LCTG) ≤100 mg crushed peanut and high >100 mg. RESULTS: Among the 68 children included, there was a 96% concordance between the OFC and BAT result for the diagnosis of PA. Of the 56 children with a positive OFC and BAT to peanut (median age: 8.8 years), the severity of an allergic reaction and the cumulative threshold dose were not correlated (P = .24). Higher Ara h 2-specific IgE and FcεRI-positive control values were both associated with severe reactions to peanut. Combining these 2 markers led to a 92% sensitivity (84%-97%) and an 82% specificity (71%-89%) for severe reactions in all subjects. For children in the LCTG, a 4-variable composite marker, including age, normalized basophil sensitivity (EC50), and FcεRI- and fMLP-positive control values, resulted in a 97% sensitivity (89%-99%) and 61% specificity (49%-71%). CONCLUSION: Distinct composite markers including BAT allergen-specific and non-allergen-specific parameters appear to be associated with severity and cumulative threshold dose in children with PA.

Emergence of pollen food allergy syndrome in asthmatic children in Paris.

BACKGROUND: Over the last few decades, the level of pollen from birch and homologous trees has increased in parts of Europe. Sensitization to birch pollen allergens (principally Bet v 1) has been associated with food cross-reactivity called pollen food allergy syndrome (PFAS). OBJECTIVE: To evaluate changes in allergic diseases due to IgE sensitization over 25 years in asthmatic children. METHODS: This was a cross-sectional retrospective study conducted in Paris. We analyzed two cohorts of asthmatic children with similar characteristics explored between 1993-1999 (old cohort = OC) and 2012-2018 (recent cohort = RC). RESULTS: 121 children were in the OC and 120 in the RC. An increase in sensitization to tree pollens was found especially for birch pollen, which was 11.6% in the OC and 31% in the RC (P = .0002). Allergic rhinitis prevalence was significantly higher in the RC than in the OC (96% vs 52%, respectively, P < .0001). IgE-mediated food allergy increased from 6% to 16% in the OC and RC, respectively, (P = .01) mainly due to PFAS. In the RC, a higher mean Bet v 1-specific IgE level was observed in children with PFAS compared to children without (105.7 KU/L ± 17.8 and 48.9 kU/L ± 15.7, respectively, P < .05). CONCLUSION: Allergic rhinitis and food allergy with tree pollen sensitization have increased in Paris over 25 years mainly due to PFAS. Environmental factors could be responsible for these modifications as described in the literature.

Childhood-onset severe hypereosinophilic asthma: efficacy of benralizumab.

Severe hypereosinophilic asthma in children is extremely rare. This letter adds to the existing literature by providing long-term follow-up, and is the first report of the marked efficacy of benralizumab after failure of other biologic treatments. https://bit.ly/2G7Tc2k.