Alérgenos recombinantes: papel no diagnóstico e na imunoterapia alérgeno-específica

Nos ultimos 30 anos tem havido um avanco notavel na identificacao, purificacao e expressao recombinante de alergenos relevantes das mais variadas fontes, incluindo acaros, insetos, mamiferos, polens, alimentos, fungos, latex e outras fontes. Estes avancos resultaram na utilizacao crescente de alergenos purificados, naturais ou recombinantes, para melhorar o diagnostico de alergia pelos metodos que dispomos, incluindo os testes cutâneos de hipersensibilidade imediata, e os metodos in vitro para medida de anticorpos IgE especificos, como ImmunoCAP, ImmunoCAP-ISAC, ELISA e MARIA. Mais recentemente, o uso de alergenos recombinantes de polen de betula (rBet v 1) e de gramas (coquetel de 5 alergenos) em imunoterapia foi relatado como seguro e eficaz, com resultados comparaveis aos obtidos usando extratos naturais, em pacientes com rinoconjuntivite alergicos a polens. No presente artigo, apresentamos revisao atualizada do uso de alergenos recombinantes em diagnostico de alergia e em imunoterapia alergeno-especifica, incluindo novas estrategias de imunoterapia. Focalizamos na avaliacao critica de estudos que investigaram sensibilidade, especificidade, reatividade cruzada e valor prognostico de metodos diagnosticos com uso de alergenos recombinantes versus extratos naturais; nas recomendacoes atuais para o uso destes novos metodos na pratica clinica; e na revisao de estudos clinicos com imunoterapia usando alergenos recombinantes realizados ate o momento. (AU) Over the past 30 years, a great deal of progress has been made in the identification, purification,and recombinant expression of relevant allergens from various sources, including mites, insects,mammals, pollens, foods, fungi, latex, and other sources. These new developments have resultedin an increasing use of purified allergens, either natural or recombinant, to improve the diagnosisof allergy via the methods currently available, including skin tests and in vitro tests for measuringspecific IgE antibodies, e.g., ImmunoCAP, ImmunoCAP-ISAC, ELISA, and MARIA. More recently,the use of recombinant allergens from birch pollen (rBet v 1) and from grass pollen (a cocktailof five allergens) in immunotherapy has been reported to be safe and effective, with resultscomparable to those obtained with natural extracts in patients with rhino-conjunctivitis due topollen allergy. In the present article, we present an up-to-date review on the use of recombinantallergens in the diagnosis of allergy and in allergen-specific immunotherapy, including newstrategies for immunotherapy. We focus on the critical analysis of studies that have investigatedsensitivity, specificity, cross-reactivity, and the prognostic value of diagnostic methods that includerecombinant allergens versus natural extracts; on current recommendations for the use of thesenew methods in clinical practice; and on the review of clinical studies using immunotherapy withrecombinant allergens performed to date. (AU)