D2.06 - Peanut allergy diagnosis. Our experience
Background
Peanut is considered one of the most allergenic foods, with increasing prevalencein recent years. Twelve peanut allergens have been identified, being Arah1, Arah2,Arah3, and Arah6 the predominant allergens worldwide. However, in Mediterraneancountries, the most common allergen is Arah9. Sensitization to the first 4 proteinsis closely associated with a higher risk of severe reactions, while sensitization toArah9 is associated with reactions of variable severity, ranging from oral allergysyndrome to anaphylactic reactions. This variability in allergic responses highlightsthe importance of characterizing sensitization profiles in every patient.
Method
Serum from 34 patients was analyzed between 01/01/2023 and 30/12/2023. Wecarried out this study using immunoblotting to detect 8 of the 12 identified peanutallergens (Arah1, Arah2, Arah3, Arah5, Arah6, Arah7, Arah8, and Arah9) aming tocofirm the most common and severe sensitizations in our setting.
Results
The sensitization patterns to different peanut proteins were analyzed (Graphic1):
- 16 of the 34 patients were monosensitized.
- Arah2, Arah6 and Arah9 monosensitization were compared. (Table 1)
- Arah9 monosensitization: 10 patients. 7 allergic, 3 sensitized. 100% cutaneous reaction and allergic to other nuts. 2 present eosinophilic esophagitis.
- Arah6 monosensitization: 4 patients. 2 anaphylaxis reaction. 2 patients allergic to cashew and pistachio, one to hazelnut, the last one just to peanut.
- Arah2 monosensitization: 2 patients. One presents cutaneous reaction and allergic to other nuts and legumes. One sensitized before intake.
- Among patients sensitized to two or more allergens, sensitization to Ara h6 was as frequent as to Ara h9. Of the 18 polysensitized patients, 11 showed reactivity to both proteins.
Conclusion
- Among patients sensitized to two or more peanut allergens, sensitization to Ara h6 is as frequent as sensitization to Ara h9.
- Ara h9 is the predominant allergen, eosinophilic esophagitis (EEo) may be a relevant comorbidity in these cases.
- Among Arah6 monosensitized anaphylaxis is frequently, epinephine need to prescribe
- Larger studies are required to validate these preliminary findings.
