Influencing factors on the safety and effectiveness of venom immunotherapy.

BACKGROUND AND OBJECTIVE: The safety profile of venom immunotherapy (VIT) is a relevant issue and considerable differences in safety and efficacy of VIT have been reported. The primary aim of this study was to evaluate the safety of ACE inhibitors and beta-blockers during VIT, which has already been published. For a second analysis, data concerning premedication and venom preparations in relation to systemic adverse events (AE) during the up-dosing phase and the first year of the maintenance phase were evaluated as well as the outcome of field stings and sting challenges. METHODS: The study was conducted as an open, prospective, observational, multicenter study. In total, 1,425 patients were enrolled and VIT was performed in 1,342 patients. RESULTS: Premedication with oral antihistamines was taken by 52.1% of patients during the up-dosing and 19.7% of patients during the maintenance phase. Taking antihistamines had no effect on the frequency of systemic AE (p=0.11) but large local reactions (LLR) were less frequently seen (OR: 0.74; 95% CI: 0.58-0.96; p=0.02). Aqueous preparations were preferentially used for up-dosing (73.0%) and depot preparations for the maintenance phase (64.5%). The type of venom preparation neither had an influence on the frequency of systemic AE nor on the effectiveness of VIT (p=0.26 and p=0.80, respectively), while LLR were less frequently seen when depot preparations were used (p<0.001). CONCLUSION: Pretreatment with oral antihistamines during VIT significantly reduces the frequency of LLR but not systemic AE. All venom preparations used were equally effective and did not differ in the frequency of systemic AE.

Limited Long-Term Impact of Insect Venom Immunotherapy on the Micro-RNA Landscape in Whole Blood.

OBJECTIVE: To perform a genome-wide characterization of changes in microRNA (miRNA) expression during the course of venom immunotherapy (VIT). METHODS: miRNA was isolated from the whole-blood of 13 allergic patients and 14 controls, who experienced no allergic reaction upon stings by honeybees and wasps. We analyzed 2549 miRNAs from the whole blood of these patients prior to VIT and 12 months after the start of VIT. The results for differential expression obtained on a microarray platform were confirmed by quantitative real-time PCR. Out of the 13 patients, 8 had a negative allergic reaction with VIT, thus indicating that this approach was successful. RESULTS: By comparing time points before and 12 months after ultrarush VIT, correlation analysis and principal component analysis both indicated a limited effect of VIT on the overall miRNA expression pattern. Volcano plot analysis based on raw P values revealed few deregulated miRNAs, most of which were increasingly expressed after VIT as compared with before VIT. Based on the 50 most altered miRNAs, no clear clustering was observed before or after VIT. CONCLUSIONS: Our results indicate an overall reduced effect of VIT on the miRNA expression pattern in whole blood.

Safety of Ultrarush Venom Immunotherapy: Comparison Between Children and Adults.

BACKGROUND: The ultrarush protocol is an attractive approach in the buildup phase of venom immunotherapy (VIT-UR). However, the degree of risk of VIT-UR in children remains unknown. The objective of this study was to compare the safety of VIT-UR in children and adults. METHODS: We performed a study based on prospectively gathered medical records of children and adults with hymenoptera venom allergy treated with VIT-UR in 3 allergy centers in Poland. RESULTS: The study population comprised 134 children (mean [SD] age, 12.6 [3.7] years; males, 70.1%) and 207 adults (mean age, 42.4 [14.0] years; males, 47.8%). The number of children in the subgroups of bee venom (BV) allergy and wasp venom (WV) allergy were comparable, although sensitization to WV was more predominant in the adult group (70.1%). Skin reactivity to both venoms was more common in children than in adults (P < .001); however, children had higher concentrations of total IgE and specific IgE to BV (both P < .001). Systemic allergic reactions (VIT-SARs) occurred in 6.2% of the patients (3.7% in children and 7.7% in adults; nonsignificant). In adults, SARs occurred more frequently in patients treated with BV than WV extracts (21.4% vs 2.6%; P < .001). The same pattern was observed in children (7.2% vs 0%; P = .058). However, VIT-SARs to BV were less frequent in children than in adults (P = .034). Similarly, no significant relationship was noted between children and adults receiving WV VIT (2.6% vs 0%; nonsignificant). The severity of VIT-SAR did not differ between children and adults. CONCLUSIONS: VIT-UR is safer in children. Age below 18 is not a risk factor for VIT-SARs.