Ischemic stroke as a rare complication of wasp venom allergy: two clinical scenarios.

Neurological complications after a single Hymenoptera insect sting are very rare. The authors of this paper describe two instances of cerebral ischemic stroke that occurred immediately after a wasp sting. Two distinct pathomechanisms involved in the cases are put forward. When diagnosing such cases, it is vital to rule out the possibility of an immunoglobulin E (IgE)-dependent reaction of hypersensitivity. However, if sIgE antibodies against wasp venom extract and/or its allergenic components are detected, after hospitalization the patient should be qualified for venom immunotherapy, which is the only efficient method of protection from severe allergic reactions caused by an insect sting. Although the incidence of ischemic stroke in patients stung by insects is very low, it is important to be aware of this complication. This will allow rapid implementation of appropriate diagnostics and treatment. The optimal stroke treatment (thrombolysis or mechanical thrombectomy) in these rare cases has not yet been established.

Changing microRNA Expression during Three-Month Wasp Venom Immunotherapy.

MicroRNAs are small non-coding molecules playing a significant regulatory role in several allergic diseases. However their role in tolerance induction remains unclear. The aim of this study was to determine the expression of selected microRNAs during the first three months of wasp venom immunotherapy (VIT). 5 adult patients with a history of severe systemic reactions after stinging by wasps and confirmed sensitization were included. Venous blood samples were collected before VIT, 24 hours after completing its initial phase and after 3 months of the maintenance therapy. A control group was comprised of 5 healthy individuals with no history of allergy. In the blood samples expression of 96 microRNAs was determined with the use of microfluidic cards. In a statistical analysis the expression was compared between the study groups as well as between the pre- and post-VIT samples. Significant differences were found between the patients with wasp venom allergy and the healthy controls in the expression of miR-601 and miR-1201 upregulated in allergic patients at every time point (p = 0.04; p = 0.015, respectively). During VIT profile of microRNA was changing with lower expression of 6 microRNAs (including miR-182, miR-342, miR-375) and higher of 11 microRNAs (including let-7d, miR-34b, miR-143). To conclude, VIT has led to some changes in the expression of microRNA associated with Th2-type inflammation and tolerance induction.

Component-resolved diagnosis in vespid venom-allergic individuals.

BACKGROUND: Hymenoptera venom-allergic patients frequently present multiple sensitisations. OBJECTIVES: To define the allergic profile by components in wasp allergic patients. To study the usefulness of specific IgE to components in cases of double sensitisation. MATERIALS AND METHODS: Wasp allergic patients who needed Polistes and/or Vespula venom immunotherapy were included. Before immunotherapy and after two years of treatment the following specific IgE (sIgE) levels were measured: Apis mellifera, Vespula spp. Polistes spp., rVes v 5, rPol d 5, nVes v 5, nPol d 5, nVes v 1, nPol d 1, nApi m 1, nApi m 2 and peroxidase. Skin tests with venoms were performed. Based on the sIgE and the skin test results, Polistes and/or Vespula immunotherapy was administered. RESULTS: Thirteen patients were included. Double sensitisation to Polistes/Vespula was detected in eight patients. Sensitisation to rVes v 5 and rPol d 5 was found in two of eight cases, to nVes v 1 and nPol d 1 in eight of 13 cases, and to nVes v 5 and nPol d 5 in 2 of 13 cases. Three patients received double immunotherapy with both wasps. One patient was treated with Vespula and nine with Polistes. sIgE levels decreased after two years of treatment. In patients who showed double sensitisation but were treated with only one venom, sIgE to both venoms decreased. CONCLUSIONS: Components analysis can be useful to study double positivity. In case of doubt, double immunotherapy should be administered. Phospholipase was found to be a major allergen in our population.

Rush immunotherapy for wasp venom allergy seems safe and effective in patients with mastocytosis.

BACKGROUND: Patients with mastocytosis and wasp venom allergy (WA) may benefit from venom immunotherapy (VIT). However, fatal insect sting reactions have been described in mastocytosis patients despite previous immunotherapy. We investigated the safety and efficacy of (rush) VIT in patients with mastocytosis and WA. OBJECTIVE: To investigate the safety and efficacy of (rush) VIT in patients with mastocytosis and WA. METHODS: We describe nine patients with cutaneous mastocytosis and WA who received VIT. Cutaneous mastocytosis was confirmed by histopathology and systemic mastocytosis was diagnosed according to World Health Organization criteria. VIT was given according to a rush protocol. Given the difference in safety and efficacy of VIT in patients with WA and honeybee venom allergy, we reviewed the literature for VIT with the focus on WA patients with mastocytosis and addressed the difference between patients with cutaneous versus systemic mastocytosis. RESULTS: Nine patients had WA and mastocytosis, of whom six had cutaneous mastocytosis, two combined cutaneous and systemic mastocytosis and one systemic mastocytosis. All patients received rush IT with wasp venom. Most patients had only mild local side effects, with no systemic side effects during the course of VIT. One patient had a systemic reaction upon injection on one occasion, during the updosing phase, with dyspnoea and hypotension, but responded well to treatment. Immunotherapy was continued after temporary dose adjustment without problems. Two patients with a previous anaphylactic reaction were re-stung, without any systemic effects. CONCLUSIONS: VIT is safe in cutaneous mastocytosis patients with WA, while caution has to be made in case of systemic mastocytosis. VIT was effective in the patients who were re-stung.

Basophil activation test in the diagnosis and monitoring of mastocytosis patients with wasp venom allergy on immunotherapy.

BACKGROUND: There is need for an accurate diagnostic test in mastocytosis patients with wasp venom allergy (WVA) and monitoring of these patients during immunotherapy (IT). In this study, we aimed to evaluate sensitivity and specificity of the Basophil Activation Test (BAT) as a diagnostic and monitoring test in patients with mastocytosis and WVA. METHODS: Seventeen patients with mastocytosis and WVA and six mastocytosis patients without WVA were included. BAT was performed before the start of IT (first visit) and at 6 weeks (second visit) and 1 year (third visit), after reaching the maintenance dose. Of 17 patients included, 11 completed the third visit. In mastocytosis patients with WVA, dose-dependent wasp-venom induced upregulation of CD63 and CD203c expression on basophils was observed compared with mastocytosis patients without WVA. Serum specific IgE, IgG4, and tryptase levels were measured in all patients. RESULTS: BAT had a sensitivity of 87% and specificity of 100% in diagnosing WVA in mastocytosis patients. Basophil allergen threshold sensitivity with respect to CD63 and CD203c was significantly decreased in the second visit compared with the first visit and increased significantly in the third visit compared with the second visit. Specific IgE levels increased significantly in the second visit compared with first and decreased significantly in the third visit compared with the second. Specific IgG4 levels rose significantly in the second visit compared with the first and on the third visit compared with the second. Tryptase levels did not change significantly during the study. CONCLUSIONS: BAT represents a diagnostic test with 100% specificity in allergic patients with mastocytosis and these patients are better to be monitored for a longer period during IT.

Basophil Activation Test in the diagnosis and monitoring of mastocytosis patients with wasp venom allergy.

Background: There is need for an accurate diagnostic test in mastocytosis patients with wasp venom allergy (WVA) and monitoring of these patients during immunotherapy (IT). In this study, we aimed to evaluate sensitivity and specificity of the Basophil Activation Test (BAT) as a diagnostic and monitoring test in patients with mastocytosis and WVA. Methods: Seventeen patients with mastocytosis and WVA and 6 mastocytosis patients without WVA were included. BAT was performed before the start of IT (1st visit) and at 6 weeks (2nd visit) and 1 year (3rd visit), after reaching the maintenance dose. Of 17 patients included, 11 complerted the 3rd visit.In mastocytosis patients with WVA, dose-dependent wasp-venom induced upregulation of CD63 and CD203c expression on basophils was observed compared to mastocytosis patients without WVA. Serum specific IgE, IgG4 and tryptase levels were measured in all patients. Results: BAT had a sensitivity of 87% and specificity of 100% in diagnosing WVA in mastocytosis patients. Basophil allergen threshold sensitivity with respect to CD63 and CD203c was significantly decreased in the second visit compared to the first visit and increased significantly in the third visit compared to the second visit. Specific IgE levels increased significantly in the 2nd visit compared to first and decreased significantly in the third visti compared to the second. Specific IgG4 levels rose significantly in the 2nd visit compared to the 1st and on the 3rd visit compared to the 2nd . Tryptase levels did not change significantly during the study. Conclusions: BAT can represent a diagnostic test in allergic patients with mastocytosis and these patients are better to be monitored for a longer period during IT. © 2013 Clinical Cytometry Society.