Wasp venom allergy screening with recombinant allergen testing. Diagnostic performance of rPol d 5 and rVes v 5 for differentiating sensitization to Vespula and Polistes subspecies.

BACKGROUND:The appropriate therapeutic management of patients with wasp-induced allergic reactions necessitates an accurate allergologic workup, entailing differentiation between sensitization against Vespula or Polistes venoms. MATERIALS AND METHODS:We studied 52 consecutive adult subjects diagnosed with hypersensitivity to wasp venoms. Cap inhibition was performed using UniCAP Specific IgE. The concentration of serum IgE against two recombinant constituents of Antigen 5 (rVes v 5 and rPol d 5) was also measured using Immuno CAP 250. The ratio between values of specific IgE against recombinant allergens was calculated and a percentage difference >50% was considered significant for specific immunization against one of the two venoms. RESULTS:The diagnostic agreement between recombinant allergens testing and CAP inhibition was 54% (kappa statistics, 0.34; 95% CI, 0.18-0.50) in the whole study population. In the 24 patients with recombinant allergens ratio >50% and non dubious results of CAP inhibition assay the diagnostic agreement was perfect (100%; kappa of agreement, 1.00; 95% CI; 1.00-1.00). DISCUSSION:The results of this study show that the assessment of specific IgE against rVes v 5 and rPol d 5 may be regarded as a low-cost screening, providing valuable diagnostic information for differentiating the sensitization against Vespula or Polistes venoms. In patients with suggestive clinical history and ratio >50% between specific IgE against rVes v 5 and specific IgE against and rPol d 5, the CAP inhibition assay may be safely withheld, thus allowing to achieve an early diagnosis at lower cost.