Efficacy and safety of honeybee and wasp tyrosine-adsorbed venom immunotherapy.

INTRODUCTION: It is acknowledged that any claim of efficacy of allergen immunotherapy must be done for each specific product, and this remains true also for venom immunotherapy (VIT). Thus, we evaluated the efficacy and safety of a specific tyrosine-adsorbed VIT for vespula spp. and honeybee in real-life. METHODS: Consecutive patients diagnosed with hymenoptera allergy, and receiving VIT for either vespula or honeybee with a tyrosine-adsorbed preparation were observed to evaluate the grade of reaction (according to Muller) at the first field re-sting. A modified ultra-rush protocol was used. RESULTS: A total of 247 patients (73 female) were observed (102 honeybee, group H, 145 vespula, group V). Seventy-five patients in group H had a re-sting, and 74/75 had a lower grade reaction at re-sting as compared to the pre-VIT reaction. Considering systemic reactions, protection was achieved in 89% of patients. In group V 118 patients were re-stung, and 76/118 patients with previous grade III-IV reaction had no more systemic reaction under VIT. Overall, considering systemic reactions, protection was achieved in 92% of subjects. Of note, in both groups there was a clear inverse correlation between the severity of pre-VIT and during VIT reactions. The duration of VIT at the time of re-sting did not affect the efficacy. The safety was overall good, with 18% ad 15.4% local reactions in groups H and V, respectively. DISCUSSION: Modified extracts, including tyrosine-absorbed, have the aim of improving the safety of VIT still yet maintaining the efficacy. Field re-sting is the best way to assess the efficacy in real life. In this observational study we could confirm the protective efficacy of the tyrosine-adsorbed extract, with a good safety expecially in the build-up using a modified-rush protocol. CONCLUSION: The tyrosine-adsorbed VIT used herein is a viable and advantageous form of treatment for hymenoptera allergy.

Large local reactions to Hymenoptera stings: Outcome of re-stings in real life.

BACKGROUND: Large local reaction to Hymenoptera stings is usually defined as a swelling >10 cm which lasts longer than 24 hours, sometimes associated with erythema, pruritus and blisters. Currently, the risk of subsequent systemic reactions after re-stings is considered low (2%-15%). Therefore, a diagnostic workup in case of large local reaction is often judged unnecessary, as well as adrenaline auto-injector and venom immunotherapy prescription. The aim of this study was to prospectively evaluate the outcome of re-stings in a real-world setting, in patients with a history of one previous large local reaction. METHODS: We consecutively enrolled patients who experienced their first large local reaction (as per EAACI definition), treated with antihistamine and steroids. They were followed for field re-stings and assessed for risk of subsequent systemic reactions. RESULTS: We enrolled 662 patients. Out of the 225 re-stung subjects, 24% did not experience reactions, 52% reported a second large local reaction and 24% had systemic reactions. The risk of subsequent systemic reactions was higher in case of skin test reactivity to Apis mellifera or Vespula species (OR 2.1 and 3.8, respectively), in particular if positive at 0.001 µg/mL concentration (OR 13.4 and 16.5, respectively). CONCLUSIONS: Systemic reactions, after a previous large local reaction, occur more frequently than that reported by literature. After analysing the predictive role of large local reactions for systemic reactions, we demonstrated that an accurate diagnostic workup may be considered, particularly skin tests. Further studies in different countries are needed to confirm these results and large local reaction management.

Anaphylactic Reactions After Discontinuation of Hymenoptera Venom Immunotherapy: A Clonal Mast Cell Disorder Should Be Suspected.

BACKGROUND: Up to 75% of patients with severe anaphylactic reactions after Hymenoptera sting are at risk of further severe reactions if re-stung. Venom immunotherapy (VIT) is highly effective in protecting individuals with ascertained Hymenoptera venom allergy (HVA) and previous severe reactions. After a 3- to 5-year VIT course, most patients remain protected after VIT discontinuation. Otherwise, a lifelong treatment should be considered in high-risk patients (eg, in mastocytosis). Several case reports evidenced that patients with mastocytosis and HVA, although protected during VIT, can re-experience severe and sometimes fatal reactions after VIT discontinuation. OBJECTIVE: To evaluate whether patients who lost protection after VIT discontinuation may suffer from clonal mast cell disorders. METHODS: The survey describes the characteristics of patients who received a full course of VIT for previous severe reactions and who experienced another severe reaction at re-sting after VIT discontinuation. Those with a Red Española de Mastocitosis score of 2 or more or a serum basal tryptase level of more than 25 ng/mL underwent a hematological workup (bone marrow biopsy, KIT mutation, expression of aberrant CD25) and/or skin biopsy. RESULTS: Nineteen patients (mean age, 56.3 years; 89.5% males) were evaluated. All of them had received at least 4 years of VIT and were protected. After VIT discontinuation they were re-stung and developed, in all but 1 case, severe anaphylactic reactions (12 with loss of consciousness, in the absence of urticaria/angioedema). Eighteen patients (94.7%) had a clonal mast cell disorder, 8 of them with normal tryptase. CONCLUSIONS: Looking at this selected population, we suggest that mastocytosis should be considered in patients developing severe reactions at re-sting after VIT discontinuation and, as a speculation, patients with mastocytosis and HVA should be VIT-treated lifelong.

Which immunotherapy product is better for patients allergic to Polistes venom? A laboratory and clinical study.

BACKGROUND: Venom immunotherapy (VIT) is highly effective in preventing allergic reactions to insect stings, but the appropriate venom must be used to achieve clinical protection. In patients with multiple positive results to venoms, molecular allergy diagnostics or CAP-inhibition may identify the causative venom. Concerning allergy to venom from Polistes spp. it has been proposed that only the European species P. dominulus should be used for VIT. However, this recommendation is not present in any international guideline. Using both laboratory and clinical data, we aimed to evaluate the reliability of this proposal. METHODS: We performed an in vitro study using CAP-inhibition to determine sensitization of 19 patients allergic to Polistes venom. The clinical study included 191 patients with positive tests to Polistes treated with VIT, 102 were treated with P. dominulus and 89 were treated with a mix of American Polistes (mAP). RESULTS: The difference in % of inhibition was significant concerning inhibition of P. dominulus sIgE by P. dominulus venom (79.8%) compared with inhibition by mAP venom (64.2%) and not significant concerning the inhibition of mAP sIgE by P. dominulus venom (80.1%) and by mAP venom (73.6%). Instead, the clinical protection from stings was not statistically different between the two kinds of venom. CONCLUSION: The data from CAP inhibition would suggest that the choice of either P. dominulus venom or mAP venom for VIT is appropriate in patients with CAP inhibition higher than 70%, but the clinical data show the same odds of protection from stings using for VIT P. dominulus or mAP venom.

Investigation on acute effects of enzyme replacement therapy and influence of clinical severity on physiological variables related to exercise tolerance in patients with late onset Pompe disease.

Exercise intolerance is one of the clinical hallmarks of late-onset Pompe disease (LOPD). We studied the acute effects of ERT on the physiological variables associated with exercise tolerance in patients chronically ERT treated. Moreover, we assessed the influence of clinical severity on the investigated variables. The day before (B) and the day after (A) ERT injection, 11 LOPD patients performed on a cycle-ergometer an exercise tolerance test to voluntary exhaustion; VO2, HR, RPE, and GAA activity were determined in B and A. The disease severity was characterized by Walton scale, 6MWT, and pulmonary function tests. No significant differences in the variables related to exercise tolerance were found in A vs B, despite a significant increase in GAA activity in peripheral lymphocytes. No differences in VO2 peak were observed between patients with only skeletal muscle impairment and patients with both skeletal and respiratory muscle impairment. Distance walked at 6MWT was significantly higher than VO2 peak expressed as percentage of normal values. In conclusion, in LOPD patients the exercise tolerance test is not acutely affected by ERT administration; the peripheral muscle component seems more prominent in determining the VO2 peak decrease than the respiratory component; VO2 peak might be more sensitive than 6MWT in estimating exercise tolerance in LOPD.

Phenotyping asthma in the elderly: allergic sensitization profile and upper airways comorbidity in patients older than 65 years.

BACKGROUND: Data about allergic rhinitis in elderly patients with asthma are lacking. OBJECTIVE: To investigate the presence of rhinitis and the role of sensitization of airborne allergens in elderly patients with asthma. METHODS: This was a multicenter cross-sectional study involving subjects at least 65 years old with asthma. Demographic features, comorbidities, and the presence of allergic respiratory disease were retrieved through interview. Skin prick tests for common allergens were performed. Associations of demographic and clinical features were evaluated in relation to asthma control and forced expiratory volume in the first second less than 80% in the total population and in the subgroup with features resembling chronic obstructive pulmonary disease. RESULTS: Of 368 elderly subjects with asthma, 101 had features resembling chronic obstructive pulmonary disease. Rhinitis was present in 59.0% of subjects (allergic rhinitis in 47.6%), with an age of onset significantly different from that of asthma (49 ± 18 vs 57 ± 18 years). At least 1 sensitization was observed in 52.4% of subjects, more frequently for house dust mite (HDM; 31.8%). The prevalence of poorly and partially controlled asthma was higher in patients sensitized to airborne allergens (odds ratio 1.64, 95% confidence interval 1.03-2.61), in particular to HDM (odds ratio 1.73, 95% confidence interval 1.05-2.85). CONCLUSION: Approximately 60% of elderly subjects with asthma had rhinitis, mainly allergic and often untreated, whose onset preceded asthma symptoms by a mean of approximately 10 years. Nonallergic asthma was better controlled than allergic asthma. However, HDM sensitization was greater in subjects with asthma with features resembling chronic obstructive pulmonary disease (39% vs 28%). When restricting analysis to this group, the negative role of HDM in overall asthma control (forced expiratory volume in first second and Asthma Control Test) was significant.