IgE reactivity patterns in patients with allergic rhinoconjunctivitis to ragweed and mugwort pollens

Abstract

Background: Differential diagnosis between ragweed and mugwort pollen allergy represents a large clinical problem in areas where both plants are present. The aim of this study was to investigate ragweed-and mugwort-sensitized patients to identify specific IgE reactivity profiles. Results were correlated to clinical findings such as medical history and health-related quality of life (HRQL). Methods: Seventy-four patients with allergic rhinoconjunctivitis between July and October were examined and underwent in vivo tests (skin-prick test [SPT] and nasal provocation). Sera were evaluated for IgE reactivity to mugwort and ragweed pollen extracts, major (Art v 1; Amb a 1) and minor (profilin and calcium-binding protein) allergens. HRQL was evaluated using a standardized questionnaire. Results: Seventy-one patients revealed positive SPT reactivity against mugwort and 60 patients against ragweed extracts. Of these patients, 74 revealed IgE antibodies against mugwort extracts, whereas anti-Art v 1 antibodies were detectable in 50 individuals. Fifty-five patients showed IgE antibodies against natural ragweed extracts; anti-Amb v 1 antibodies were detected in six cases only. Using standardized clinical history and HRQL questionnaires we were not able to detect any differences within different reactivity patterns. Conclusion: Within the investigated population of 74 weed-allergic patients the prevalence of true mugwort and ragweed sensitization can be calculated as 68 and 8%. High prevalence of ragweed sensitization when testing with full extracts can be explained by cross-reactivity between other weeds, e. g., mugwort rather than cosensitization. Differences in medical history and HRQL between different reactivity patterns were not detectable. (Am J Rhinol Allergy 26, 31-35, 2012; doi: 10.2500/ajra.2012.26.3698)