Monoclonal antibody-based assay for Alt a1, a major Alternaria allergen.
BACKGROUND
Allergenic materials from Alternaria are significant causes of human disease. One 31-kD glycoprotein, designated Alt a1, has been described previously as being a significant allergen.


OBJECTIVE
The purpose of this study is to characterize purified Alt a1 and to provide a method for measuring it in laboratory and environmental samples.


METHODS
Monoclonal antibodies directed to the purified allergen were produced and used to construct a double monoclonal assay for Alt a1. The purified allergen detected by this assay was tested for IgE binding in vitro and in vivo.


RESULTS
Purified allergen detected by this assay was shown to bind IgE from patients sensitive to Alternaria and gave a positive skin test in 15 of 16 patients skin test reactive to commercial Alternaria extracts. The assay is sensitive to Alt a1 concentrations as low as 0.2 microg/nmL and is very specific for the allergen. The three commercial Alternaria extracts assayed contained measurable quantities of the allergen varying from 12 to 84 microg/mL.


CONCLUSIONS
Alt a1 is a significant Alternaria allergen. The ability to measure this allergen may assist in standardizing Alternaria extracts and lead to an understanding of the significance of exposure to this allergen.
Section of Allergy/Asthma/Immunology, The Children's Mercy Hospital, Kansas City, Missouri 64108, USA.
J
J
Portnoy
D
D
Brothers
F
F
Pacheco
J
J
Landuyt
C
C
Barnes
D000485:Allergens / Q000032:analysis*; D000528:Alternaria / Q000276:immunology*; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D006801:Humans; D015151:Immunoblotting; D007073:Immunoglobulin E / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D012882:Skin Tests
D000485:Allergens; D000911:Antibodies, Monoclonal; D007073:Immunoglobulin E