Misleading Allergens in the Diagnosis of Latex Allergy: Profilin and Cross-Reactive Carbohydrate Determinants.

It has been suggested that latex-specific IgE analysis may lead to false-positive results, especially in patients with pollen allergy. In the present study, the reasons underlying clinically irrelevant latex-specific IgE positivity were investigated.

Thirty patients with latex allergy (group 1), 89 patients sensitised to aeroallergens (group 2a), and 98 healthy individuals without allergy (group 2b) were enrolled. Participants from all 3 groups were subjected to skin prick tests with aeroallergens including latex, latex-specific IgE analysis (ImmunoCAP), and nasal provocation test with latex. All cases demonstrating positive latex-specific IgE also underwent specific IgE tests (ImmunoCAP) with latex profilin, birch pollen profilin, peach lipid transfer protein, and pineapple bromelain as cross-reactive carbohydrate determinants.

Comparison of the atopic and healthy control groups showed that the rate of positive latex-specific IgE was significantly higher in group 2a. Latex profilin-, birch pollen profilin-, and bromelain-specific IgE were remarkably higher in group 2a.

False positivity to latex-specific IgE in ImmunoCAP analysis may be observed in approximately 19% of patients with pollen allergy. Profilins and bromelain are the main contributors to clinically irrelevant positive latex-specific IgE.