Alérgenos de pólen de Lolium multiflorum (Lam. 1779):determinação da reatividade cruzada de anticorpos IgE aoscomponentes alergênicos de extratos comerciais de gramíneas
Background: Lolium multiflorum (Lm) grass pollen, Poaceae family, is the major cause ofpollinosis in South Brazil. There are no studies evaluating the cross-reactivity betweenallergenic fractions from L. multiflorum and other pollen grass species.Objective: To evaluate the sensitization to Lm pollen allergens in patients with pollinosisthrough the detection of specific IgE by skin prick test (SPT) and immunoassays (ELISA). Tocharacterize immunodominant fractions from L. multiflorum pollen allergens, and crossreactivitywith other allergens from commercial grass pollen extracts.Methods: Thirty eight serum samples from patients with seasonal allergic rhinitis (SARgroup), 35 serum samples from patients with perennial allergic rhinitis (PAR group) and 30serum samples from non atopic patients (NA group) were tested for IgE reactivity. Thesensitization was evaluated using SPT and IgE specific levels against L. multiflorum pollenextract were determined by ELISA. Inhibition ELISA and Immunoblotting were used toevaluate the cross-reactivity between allergens from L. multiflorum and commercial grasspollen extracts.Results: Serum specific IgE antibodies against Lm were detected in 100% of patients fromSAR group and in 8.6% of patients from PAR group. Inhibitions observed in specific IgEELISA demonstrated Lm cross-reactivity between homologous (Lm) and heterologous (L.perenne [Lp] or Gramíneas II [GII]) grass pollen extracts, but not for Gramíneas I (GI).Fourteen IgE binding fractions were observed and the fractions of 26, 28 and 32 kDa were themost frequent (> 90%). For IgE Immunoblotting inhibition Lm, Lp and GII inhibitedsignificantly IgE binding to the most Immunodominant fractions of Lm, particularly the55kDa fraction. The 26 kDa fraction were not inhibited by the Lp extract, but it was inhibitedby Lm and, GII in lower proportion.Conclusion: Lm pollen extract is more appropriate instead of other phylogenetic related grasspollens for determining quantitative sensitization in diagnostic and therapeutic purposes topollinosis due to L. multiflorum pollen.
Advisor:Maria Aparecida de Souza; Ernesto Akio Taketomi; Nelson Augusto Rosario Filho; Mônica Camargo Sopelete
School:Universidade Federal de Uberlândia
Source Type:Master's Thesis
Grass pollen allergen
Date of Publication:05/28/2007