Peanut Component Ara h 1 and 2 Sensitization in Patients with Food Allergy in Kuwait

Abstract

Introduction: There is limited knowledge on the sensitization patterns to peanut proteins and food allergy in the Middle East. The objective of this study is to analyze the relationship between sensitization patterns to peanut proteins and clinical symptoms in a group of patients with physician-diagnosed peanut allergy (PA) in Kuwait.

Methods: PA patients were evaluated by the skin prick test (SPT), serum total IgE, peanut-specific IgE (sIgE), and sIgE against Ara h 1-3, 8, and 9, and clinical data were collected.

Results: Sixty-nine patients were included. A positive correlation between peanut SPT and sIgE was detected for all 3 storage proteins (Ara h 1-3) in patients <6 years old and for Ara h 1 and 2 in older patients. ROC analysis of positive correlations showed that oral food challenge should be considered for definite diagnosis of PA only if the level of Ara h 2 is <22.25 KUA/L, with level of Ara h 2 ≥15.4 allowing the detection of systemic reactions with a sensitivity of 55.56%. Patients presenting with systemic reactions more frequently had positive Ara h 1 (88.9%) and Ara h 2 (83.3%), compared with 44.1% and 52.9% in those with local reaction (p = 0.0046 and p = 0.0378). The levels of Ara h 1 and 2 were also significantly higher in patients with systemic reactions compared to those with a local reaction, with those differences being especially relevant for Ara h 2 (15.9 vs. 0.4) (p = 0.0005).

Conclusions: The pattern of sensitization to peanut proteins in the Middle East is similar to that of the Western world. Measurement of sIgE antibodies to Ara h 1, 2, and 3 is useful in the diagnosis of PA and in the investigation of reactions to raw and roasted peanuts.

Keywords: Food allergy; IgE-mediated allergy; ImmunoCAP; Peanut allergy; Recombinant allergens.