Specific Immunotherapy for Common Grass Pollen Allergies: Pertinence of a Five Grass Pollen Vaccine

Abstract

Patients throughout Europe are concomitantly exposed to multiple pollens from distinct Pooideae species. Given the overlap in pollination calendars and similar grain morphology, it is not possible to identify which grass species are present in the environment from pollen counts. Furthermore, neither serum IgE reactivity nor skin prick testing allow the identification of which grass species are involved in patient sensitisation. Due to their high level of amino acid sequence homology (e.g., >90% for group 1, 55–80% for group 5), significant cross-immunogenicity is observed between allergens from Pooideae pollens. Nevertheless, pollen allergens also contain species-specific T or B cell epitopes, and substantial quantitative differences exist in allergen (e.g., groups 1 and 5) composition between pollens from distinct grass species. In this context, a mixture of pollens from common and well-characterised Pooideae such as Anthoxanthum odoratum, Dactylis glomerata, Lolium perenne, Phleum pratense and Poa pratensis is suitable for immunotherapy purposes because (1) it has been validated, both in terms of safety and efficacy, by established clinical practice; (2) it reflects natural exposure and sensitisation conditions; (3) it ensures a consistent and well-balanced composition of critical allergens, thus extending the repertoire of T and B cell epitopes present in the vaccine.

Five-grass-pollen sublingual immunotherapy tablet for the treatment of grass-pollen-induced allergic rhinoconjunctivitis: 5 years of experience

“…Grass allergens belonging to groups 1 (glycoproteins) and 5 (non-glycosylated proteins) are well characterized and constitute the major allergens, which account for more than 80% of the allergenic potential of grasspollen [7,43]. Groups two and three constitute minor allergens, which are recognized by 40-60% of allergic patients [7].…”

“…A 5-grass-pollen extract better represents the natural exposure and sensitization conditions encountered by allergic patients, because the corresponding grass species are broadly distributed throughout North America and Europe, and polysensitization is common among patients [7,42]. Although high amino-acid sequence homology is found between Pooideae grass-pollens for group 1 and 5 allergens (90 and 55-80% homology, respectively), qualitative and quantitative differences exist in their expression between grass species [7,36,42]. Consequently, variations among allergic patients have been observed in the degree of sensitization toward both shared and species-specific epitopes from these allergens [7,36].…”

“…Although high amino-acid sequence homology is found between Pooideae grass-pollens for group 1 and 5 allergens (90 and 55-80% homology, respectively), qualitative and quantitative differences exist in their expression between grass species [7,36,42]. Consequently, variations among allergic patients have been observed in the degree of sensitization toward both shared and species-specific epitopes from these allergens [7,36]. Moreover, a recent study highlighted that polysensitization toward grasspollen allergens not only occurs at the IgE level, but also at the T-cell level, and Pooideae species-specific T-cell epitopes that are minimally cross-reactive exist among group 1 and 5 allergens [46].…”

“…Globally, the prevalence of seasonal ('hay fever') and perennial AR ranges from 7 to 42 and 1 to 13%, respectively, with the former being more common in children than adults [6]. The length of exposure to seasonal allergens is dependent on geographic location and climatic conditions [4]; in Europe, the main pollen season typically occurs from March to July, with slight variations according to latitude [7].Approximately 500 million people worldwide [6], including an estimated 30-60 million in the USA [4] …”

Pollen allergy in Rostov-on-Don

“…АСИТ проводили классиче ским методом -подкожными инъекциями водно солевых экстрактов аллергенов по стандартной схе ме, индивидуализированной для каждого пациента. Учитывая принципы выбора оптимального набора этиологически ответственных аллергенов с наибо лее полным антигенным представительством [8,9], при наличии сенсибилизации к нескольким аллер генам сорных трав (из «родственного букета» -по лыни, амброзии, циклахены и подсолнечника) мы использовали для лечения микст аллерген. Эффек тивность АСИТ оценивали по степени выраженно сти клинических проявлений в период поллиноза, их продолжительности, использования симптома тических средств и их эффективности.…”