Asymptomatic Sensitization to Hymenoptera Venom Is Related to Total Immunoglobulin E Levels

Abstract

Background: The detection of specific serum immunoglobulin E (sIgE) to Hymenoptera venoms is an established diagnostic tool to diagnose insect venom hypersensitivity. However, the specificity of sIgE detection is a debated issue. Methods: In 145 subjects, total IgE (tIgE) and sIgE to Hymenoptera venoms as well as sIgE to rapeseed as a marker of cross-reactive carbohydrate determinants were measured. In addition, an atopy score was determined for each patient. We looked for a possible association between tIgE and the presence of sIgE in subjects with a negative history of large local or systemic reactions to insect stings. Results: Fifteen of 65 subjects (23.1%) with low levels of tIgE (<50 kU/l) had sIgE for bee or wasp venom, and 23 of 47 subjects (48.9%) with a tIgE from 50 to 250 kU/l showed sIgE. The highest rate of asymptomatic sensitization (22 of 33; 66.7%) was found in patients with tIgE levels higher than 250 kU/l. Median sIgE was approximately 4.8 times higher in subjects with tIgE levels above 250 kU/l than in those with tIgE levels <50 kU/l. Interestingly, a significant difference in median tIgE was recorded between individuals with and without sIgE to rapeseed [776.5 kU/l (25, 75% percentiles: 252.5, 2,000.0) vs. 50.5 kU/l (20.1, 172.0), respectively; p < 0001]. Conclusion: Specific antibodies are frequently seen in individuals with high tIgE, but appear to be largely irrelevant in clinical terms. This might lead to misdiagnosis in persons with an inconclusive sting history.