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Der p 2 isoallergens have different allergenicity, and quantification with 2‐site ELISA using monoclonal antibodies is influenced by the isoallergens
Author(s) -
Park J. W.,
Kim K. S.,
Jin H. S.,
Kim C. W.,
Kang D. B.,
Choi S. Y.,
Yong T.S.,
Oh S. H.,
Hong C.S.
Publication year - 2002
Publication title -
clinical and experimental allergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.462
H-Index - 154
eISSN - 1365-2222
pISSN - 0954-7894
DOI - 10.1046/j.1365-2222.2002.01421.x
Subject(s) - monoclonal antibody , recombinant dna , immunoglobulin e , microbiology and biotechnology , antibody , chemistry , immunology , biology , biochemistry , gene
Summary Background Der p 2 isoallergens have been reported and the possibility of different allergenicity has also been suggested. In addition, the quantification with 2‐site ELISA may be affected by the isoallergens. Objectives Two different recombinant Der p 2 (rDer p 2) isoallergens were compared in terms of human IgE responses and the reliability of quantification of them with two‐site ELISA kits which use monoclonal antibodies (mAbs) as capture and detection of Der p 2. Methods Seven different Der p 2 cDNA from the cultured Dermatophagoides pteronyssinus (DP) were cloned and polymorphism in nine amino acid residues was found. Two different recombinant isoallergens (rDer p 2A and rDer p 2B) were expressed and compared to their human IgE immune responses by ELISA and the ELISA inhibition test with 23 sera of DP‐allergic patients. The reliability of quantification of two different available 2‐site ELISA kits, which used mAbs for capture and detection of Der p 2, was evaluated. Results The ELISA optical density of rDer p 2B‐specific IgE (sIgE) was higher than that of rDer p 2A ( P < 0.001). The ELISA inhibition curve of rDer p 2B sIgE in pool I sera ( n = 5; high sIgE both to rDer p 2A and rDer p 2B) did not show any differences in the 50% inhibition concentration and maximum inhibitory percentage of rDer p 2A and rDer p 2B sIgE. However, with pool II sera ( n = 5; markedly higher sIgE to rDer p 2B than rDer p 2A), the 50% inhibitory concentrations (10 µg/mL vs. 40 ng/mL) and maximum inhibitory percentage (61% vs. 99%) of rDer p 2B sIgE with the two recombinant isoallergens were quite different. rDer p 2B could be quantified with two different 2‐site ELISA kits, but rDer p 2A was detected by only one kit. Conclusion We conclude that isoallergens of Der p 2 may have different IgE immune responses. Quantification of Der p 2 with 2‐site ELISA kits that adopted mAbs, might be affected by the prevalent form of the isoallergens in reservoir dust.