Three peanut-allergic/sensitized phenotypes with gender difference

Background: Peanut-allergic reactions are heterogeneous ranging from mild symptoms to anaphylaxis.

Objective: Identify peanut-allergic/sensitized phenotypes to personalize patient management.

Methods: A combined factor and cluster analysis was used to study the phenotypes of 696 patients diagnosed with peanut sensitization and enrolled in the MIRABEL survey. The method was first applied to the 247 patients with an oral food challenge (OFC). It was then applied to the 449 patients without OFC to confirm the findings in an independent population.

Results: Three independent clusters emerged from the OFC subgroup. Cluster 1, 'Severe peanut allergy with little allergic multi-morbidity' (123 subjects), had the highest proportion of patients with positive OFC (92%), a medium level of peanut protein inducing a positive OFC (235 mg), lower percentage of allergic multi-morbidity (2% asthma plus atopic dermatitis (A + AD), no cases of A + AD + multiple food allergies (MFA)). Cluster 2, 'Severe peanut allergy with frequent allergic multi-morbidity' (62 subjects), had a high proportion of patients with positive OFC (85%) with the lowest level of peanut protein inducing a positive OFC (112 mg), 89% allergic subjects, 100% with allergic multi-morbidity (A + AD) and 84% with A + AD + MFA. Cluster 3, 'Mild peanut-allergic/sensitized phenotype' (62 subjects), had the lowest mean age, the lowest proportion of patients with positive OFC (53%) with a high level of peanut protein inducing a positive OFC (770 mg), a low percentage of allergic multi-morbidity (48% A + AD + MFA). The two severe peanut-allergic phenotypes were more frequent in girls. The same clusters were found in the subgroup of patients without OFC.

Conclusion & clinical relevance: Besides the classic markers associated with lower threshold doses of OFC (such as SPT and rAra h 2), allergic multi-morbidity and female gender should also be taken into account to better adapt the progressive dosage of provocation tests.