Mineaki Watanabe

Measurement of Hymenoptera venom specific IgE by the IMMULITE 3gAllergy in subjects with negative or positive results by ImmunoCAP

Background Patients may receive negative results from a specific IgE (sIgE) test such as the ImmunoCAP (CAP) despite a documented history of systemic reaction to a Hymenoptera sting. Thus, further testing may be required using another serological method or venom skin prick tests to confirm allergy diagnosis and correct species. Objective To evaluate the sensitivity and the specificity of CAP and IMMULITE 3gAllergy (IMMULITE) for detecting sIgE to Paper wasp (WA) and Yellow Jacket (YJ) venoms using patient clinical history as the comparator. Methods Sera from 70 participants with a history of systemic reactions (SR) to WA and/or YJ stings were tested using CAP and IMMULITE. Fifty participants from this group had negative results on CAP. To assess specificity, sera from 71 participants who had never experienced either a WA or YJ sting were tested using CAP and IMMULITE. Fifty participants from this group tested positive using CAP. Results In participants with a history of systemic reaction to a Hymenoptera sting, yet who tested negative for WA and/or YJ sIgE according to CAP, the positivity rate according to IMMULITE was 20-42% using 0.10 IUA/mL as the limit of detection (LoD), per the manufacturers specification. When the LoD for CAP (0.35 IUA/mL) was applied to the IMMULITE results, positivity according to IMMULITE was 14-26%. Overall, sensitivity, specificity, and agreement with SR were greater for IMMULITE than for CAP. For YJ: sensitivity (IMMULITE:CAP), 42.8%:28.5%; specificity, 53.5%:39.4%; agreement, 48.2%:34%. For WA, sensitivity (IMMULITE:CAP), 58.6%:28.5%; specificity, 49.3%:47.8%; agreement, 43.9%:38.3%. Conclusion The IMMULITE performed well for detecting sIgE to Hymenoptera venom

Epidemiologic Investigation of Hornet and Paper Wasp Stings in Forest Workers and Electrical Facility Field Workers in Japan

BACKGROUNDnForestry and field workers who work outdoors are at high risk for Hymenoptera stings and may develop occupation-related allergies from being stung. However, clinical and immunological surveys of Hymenoptera stings in the occupational setting have rarely been reported. We surveyed the natural history of Hymenoptera stings in Japanese forestry workers (FWs) and electrical facility field workers (EFFWs), and we assessed the utility of measuring specific (s)IgE Ab to Hymenptera venom.nnnMETHODSnQuestionnaires on hornet and paper wasp stings were completed by 999 FWs, 354 EFFWs, and 365 office workers as controls between July and November 2009. Sera from these participants were tested for sIgE Ab levels to Hymenptera venom with a CAP system using a fluoroenzyme immunoassay.nnnRESULTSnOf the participants who had experienced Hymenoptera stings, 914 (91.5%) were FWs, 293 (82.8%) were EFFWs, and 295 (80.8%) were controls. Of the participants who had experienced systemic reactions, 210 (21.0%) were FWs, 51 (14.4%) were EFFWs, and 39 (10.7%) were controls. sIgE Ab in response to hornet and wasp venom was positive (≥ class 2) in 42.4% and 41.4% of FWs, 30.1% and 31.4% of EFFWs, and 15.1% and 18.1% of controls, respectively. The likelihood of being sIgE-positive to wasp and hornet venom was significantly higher in FWs and EFFWs than in controls (P < 0.05).nnnCONCLUSIONSn21% of FWs and 14% of EFFWs had experienced systemic reactions to Hymenoptera stings with a higher frequency compared with office workers in the same area. 40% of FWs and 30% of EFFWs had sera that were sIgE positive to Hymenoptera venom.BACKGROUNDnForestry and field workers who work outdoors are at high risk for Hymenoptera stings and may develop occupation-related allergies from being stung. However, clinical and immunological surveys of Hymenoptera stings in the occupational setting have rarely been reported. We surveyed the natural history of Hymenoptera stings in Japanese forestry workers (FWs) and electrical facility field workers (EFFWs), and we assessed the utility of measuring specific (s)IgE Ab to Hymenptera venom.nnnMETHODSnQuestionnaires on hornet and paper wasp stings were completed by 999 FWs, 354 EFFWs, and 365 office workers as controls between July and November 2009. Sera from these participants were tested for sIgE Ab levels to Hymenptera venom with a CAP system using a fluoroenzyme immunoassay.nnnRESULTSnOf the participants who had experienced Hymenoptera stings, 914 (91.5%) were FWs, 293 (82.8%) were EFFWs, and 295 (80.8%) were controls. Of the participants who had experienced systemic reactions, 210 (21.0%) were FWs, 51 (14.4%) were EFFWs, and 39 (10.7%) were controls. sIgE Ab in response to hornet and wasp venom was positive (≥ class 2) in 42.4% and 41.4% of FWs, 30.1% and 31.4% of EFFWs, and 15.1% and 18.1% of controls, respectively. The likelihood of being sIgE-positive to wasp and hornet venom was significantly higher in FWs and EFFWs than in controls (P < 0.05).nnnCONCLUSIONSn21% of FWs and 14% of EFFWs had experienced systemic reactions to Hymenoptera stings with a higher frequency compared with office workers in the same area. 40% of FWs and 30% of EFFWs had sera that were sIgE positive to Hymenoptera venom.

Improved sensitivity to venom specific-immunoglobulin E by spiking with the allergen component in Japanese patients suspected of Hymenoptera venom allergy

BACKGROUNDnVes v 5 and Pol d 5, which constitute antigen 5, are recognized as the major, most potent allergens of family Vespidae. Several studies have reported the diagnostic sensitivity of the novel recombinant (r)Ves v 5 and rPol d 5 allergens in routine clinical laboratory settings by analyzing a group of Vespula and Polistes venom-allergic patients. In this study, we analyzed the sensitivity to venom specific (s)IgE by spiking with rVes v 5 and rPol d 5 in Japanese patients suspected of Hymenoptera venom allergy.nnnMETHODSnSubjects were 41 patients who had experienced systemic reactions to hornet and/or paper wasp stings. Levels of serum sIgE against hornet and paper wasp venom by spiking with rVes v 5 and rPold d 5, respectively, as improvement testing, compared with hornet and paper wasp venom, as conventional testing, were measured by ImmunoCAP.nnnRESULTSnOf the 41 patients, 33 (80.5%) were positive (≥0.35 UA/ml) for hornet and/or paper wasp venom in conventional sIgE testing. sIgE levels correlated significantly (P < 0.01) between hornet (R = 0.92) or paper wasp venom (R = 0.78) in improvement testing and conventional testing. To determine specificity, 20 volunteers who had never experienced a Hymenoptera sting were all negative for sIgE against these venoms in both improvement and conventional testing. Improved sensitivity was seen in 8 patients negative for sIgE against both venoms in conventional testing, while improvement testing revealed sIgE against hornet or paper wasp venom in 5 (total 38 (92.7%)) patients.nnnCONCLUSIONSnThe measurement of sIgE following spiking of rVes v 5 and rPol d 5 by conventional testing in Japanese subjects with sIgE against hornet and paper wasp venom, respectively, improved the sensitivity for detecting Hymenoptera venom allergy. Improvement testing for measuring sIgE levels against hornet and paper wasp venom has potential for serologically elucidating Hymenoptera allergy in Japan.

Sensitization of specific IgE-positive Japanese who have experienced Hymenoptera stings to recombinant versions of the Ves v 1 and Ves v 5 allergens in hornet venom.

The Vespula allergen is a 37-kDa phospholipase A1 known as Ves v 1.1 Ves v 5 (antigen 5) is a 23-kDa protein found in Vespula venom.1 Recently, several studies reported the diagnostic sensitivity of the novel recombinant Ves v 5 (rVes v 5) and rVes 1 allergens in a routine clinical laboratory setting by analyzing a group of Vespula venom-allergic patients.2,3 Although Ves v 5 is by far the most important allergen in Vespula venom, including hornet venom, some people are sensitized to only Ves v 1. Of note, neither Ves v 5 nor Ves v 1 is found in honey bee venom. Recombinant versions of the Ves v 5 and rVes v 1 allergen components (rVes v 5 and rVes v 1, respectively), which are both expressed in insect cells, were developed in 2010 and 2011, respectively, for use in ImmunoCAP solid-phase immunoglobulin (Ig)E assay (capsulated hydrophilic carrier polymer (CAP)-fluoro-enzyme immunoassay (FEIA); Phadia, Uppsala, Sweden). In this study, we analyzed the sensitization of specific (s)IgE-positive individuals who had experienced Hymenoptera stings to rVes v 1 and rVes v 5. Subjects were 27 Japanese (21 men, 6 women; mean age, 61.9 ± 9.5 years; range, 39e81 years) who had experienced Hymenoptera stings and the subsequent systemic reaction and who had visited Dokkyo Medical University between March and December 2013. Twenty volunteers (18 men, 2 women; mean age, 32.6 ± 4.5 years; range, 25e51 years) who had never experienced a Hymenoptera sting were enrolled as controls. Severity of systemic reactions was graded according to Mueller4 as follows: Grade 1e3 (mild), 17 subjects; and Grade 4 (severe), 10 subjects. The total number of stings occurring in a period of no longer than 5 years was classified as few (1e4 stings) in 20 subjects and many ( 5 stings) in 7. All the participants completed a medical examination involving an interview with an allergist and underwent peripheral blood tests. This study was approved by the Dokkyo Medical University Research Ethics Committee, and each participant provided written informed consent prior to study enrollment. The intervals between the last sting and peripheral blood collection differed among the subjects. Levels of serum sIgE against hornet venom, rVes v 1, and rVes v 5 were measured by Phadia (Tokyo, Japan). Detection of sIgE by the CAP system using FEIA was expressed in quantitative units (UA/ml) or as a traditional spectrum of 7 semi-quantitative classes ranging from class 0 (<0.35 UA/ml) to

Wasp venom allergy: effect of anti-IgE antibody on wasp venom anaphylaxis in a mouse model.

BACKGROUNDnAlthough anti-IgE antibody (Ab) therapy was recently shown to be effective in patients with bronchial asthma, no study has reported the effect of IgE therapy in the prevention of wasp venom anaphylaxis. In this study, we used a mouse model of wasp venom allergy to investigate the effect of anti-IgE Ab on wasp venom anaphylaxis.nnnMETHODSnWe developed a mouse model of wasp venom allergy by intraperitoneally (i.p.) injecting wasp venom into BALB/c mice twice on experimental day (day) 0 and 7. On day 20, a group of mice received an i.p. injection of mouse anti-IgE Ab as a pretreatment, and another group received rat anti-IgG1 Ab. On day 21, the animals were challenged by i.p. injection of wasp venom, and 30 min later, body temperature was measured and serum levels of leukotriene (LT) B4 and LTC4 were determined using enzyme immunoassay.nnnRESULTSnThe body temperature of mice treated with anti-IgE Ab and controls before and after wasp venom challenge was 37.8±0.2 vs 37.7± 0.3°C before challenge and 37.8±0.2 vs 37.1± 0.3°C after challenge, respectively, showing that anti-IgE Ab treatment significantly prevented body temperature from falling (p <0.05). Furthermore, anti-IgE Ab treatment reduced total serum IgE levels in the treated mice (42.2±15.9 pg/ml), compared with controls (105.9±23.1 pg/ml, p <0.05), and inhibited the secretion of LTC4 in the treated mice (32.0±18.8 pg/ml), but not in the controls (162.4±12.4 pg/ml, p <0.05), following challenge with wasp venom.nnnCONCLUSIONnThe results of the present study indicate that anti-IgE Ab treatment is an effective preventive measure against wasp venom-induced anaphylaxis.