Dipeptidyl peptidase IV of the Vespa velutina nigrithorax venom is recognized as a relevant allergen.

BACKGROUND: Vespa velutina nigrithorax (VVN), typically known as the Asian yellow-legged wasp, has been one of the most significant invasive species in western Europe since 2010. Currently, VVN has become the most prevalent cause of Hymenoptera anaphylaxis in the north and northwestern Spain. For this reason, it is crucial to diagnose anaphylaxis cases in the acute moment for carrying out the best available treatment as soon as possible. OBJECTIVE: To achieve a complete understanding of the venom allergen composition that will help to develop efficient diagnostics and immunotherapy treatments on the basis of this venom. METHODS: In this study, autochthonous VVN venom was obtained and characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, isoelectric focusing, followed by a mass spectrometry analysis. In addition, the allergenic sensitization profile of patients diagnosed with allergy to VVN in the Allergology Service of Navarra University Hospital between the years 2017 and 2020 was studied by immunoblotting and specific IgE (ImmunoCAP, Thermo Fisher Scientific, Uppsala, Sweden). RESULTS: Two new allergens (dipeptidyl peptidase IV and serin protease) were identified in the autochthonous VVN venom, and their identity was confirmed by liquid chromatography-mass spectrometry analysis. The study by ImmunoCAP using sera from 12 patients who had a systemic reaction after a VVN sting revealed groups 5 and 1 as predominant allergens (92% and 34%, respectively). Furthermore, the immunoblotting assay recognized dipeptidyl peptidase IV (50%) in the sera of these patients. CONCLUSION: Serine protease and the dipeptidyl peptidase IV are components of the VVN venom, and the latter is an allergen recognized in the studied population.

Tolerability and surrogate efficacy parameters of a polymerized depot mixture pollen extracts without dilutional effect.

Aim: To evaluate tolerability of subcutaneous immunotherapy, in a polymerized mixture (Olea europaea/Phleum pratense) depot presentation. Patients & methods: A total of 47 poly-allergic patients received: an abbreviated schedule with three injections at weekly intervals or a cluster schedule with two administrations in 1 day. Both treatments continued with 3 monthly maintenance administrations. Results: Two systemic reactions, (4.3%). One grade 0 and one grade I. No local reactions. Immunoglobulin levels, increased significantly at final visit versus baseline in sIgG and sIgG4; in both schedules and allergens, no significant changes in specific immunoglobulin E levels were detected. Cutaneous reactivity at final visit decreased significantly. Conclusion: Both administration schedules with polymerized mixture of O. europaea/P. pratense, presented an excellent tolerability profile and induced preliminary efficacy changes.

Randomized dose-response study of subcutaneous immunotherapy with a Dermatophagoides pteronyssinus extract in patients with respiratory allergy.

AIM: To evaluate the efficacy of Dermatophagoides pteronyssinus (DPT) subcutaneous immunotherapy in allergic rhinoconjunctivitis patients. PATIENTS & METHODS: This 17-week double-blind study randomized 136 patients (95 evaluable) to five dose groups of DPT depot extract (0.0625-0.75 skin prick test [SPT] units) or placebo, administered in a six updosing schedule. RESULTS: A dose-response was observed for clinical efficacy (allergen concentration needed to induce a positive nasal provocation test response from baseline to final visit) and safety (adverse reactions). Local and systemic reactions occurred with 14.8 and 6.4% of administered doses, respectively; a single anaphylactic reaction occurred in each of Groups 3, 4 and 5 (0.3% of doses). CONCLUSION: The risk-benefit profile appeared most favorable with a DPT dose of 0.125 SPT units.

Specific sublingual immunotherapy with peach LTP (Pru p 3). One year treatment: a case report.

INTRODUCTION: Food allergy is an increasing problem with limited therapeutic approaches apart from to the eviction diet. CASE PRESENTATION: A 40-year-old female patient with food allergy symptoms was polysensitized to almost all vegetable food since the age of 36; the onset of symptoms was during pregnancy. The allergological study demonstrated positive skin prick tests (SPT) to nuts, legumes, cereals, spices, several fresh fruits including peach, and other groups of vegetable foods however, it was negative to common aeroallergens. Serum specific IgE levels were negative (<0.35 kU/L) to profilin and carbohydrate determinants, but positive to Pru p 3 (3.5 kU/L). Positive double-blind placebo-controlled food challenge to peach confirmed the allergic disease. She received specific sublingual immunotherapy with native Pru p 3 at a concentration of 40 mug/ml with 5 administrations per week and a cumulative dose of 200 mug of nPru p 3 per month. After an ultra-rush build-up phase concluded in one day she continued therapy during a year with 5 administrations per week. The clinical evolution and laboratory studies demonstrated an early reduction on SPT reactions with no relevant changes on serum specific IgE, IgG, IgG(1) and IgG(4) to Pru p 3 during the immunotherapy period. The challenge test was negative 4 months after the beginning of the SLIT. Regarding clinical response she markedly improved after the first month of treatment, and by the 3th month she had no major vegetable dietary restrictions, except for nuts and pepper. CONCLUSION: These results demonstrate the excellent efficacy and safety of sublingual specific protein immunotherapy developed according to the patient specific sensitivity profile to Pru p3.

Recombinant hypoallergens for immunotherapy of Parietaria judaica pollen allergy.

Recombinant allergens are a promising alternative to crude allergen extracts for diagnosis and therapy of allergic diseases. Genetically modified allergen derivatives with reduced allergenic activity but retaining their immunogenicity have also been produced to increase safety and specificity of allergen-specific immunotherapy. When a limited number of allergens are responsible for most of the allergenic activity, fusion proteins comprising these major allergens can be used to simplify vaccine development. Three different allergen fusions of Par j 1 and Par j 2, the major allergens from Parietaria judaica, were characterized. Two of them (Q1 and Q2) showing reduced allergenicity but conserved immunogenicity represent suitable candidates for allergen-specific immunotherapy against P. judaica pollen allergy.