A new method to bind allergens for the measurement of specific IgE antibodies.
BACKGROUND
Detection of allergen-specific IgE antibodies in patients' sera plays a key role for the diagnosis of IgE-mediated allergy. If no validated test system is available, diagnostic tools must be developed, usually by coupling or binding the allergens to a solid phase. Streptavidin ImmunoCAP is a new solid phase for binding of allergens which can be used in the Pharmacia CAP system.


OBJECTIVE
It was the aim of this study to assess the diagnostic validity of Streptavidin ImmunoCAP.


METHODS
Biotinylation and allergen concentration for binding to Streptavidin ImmunoCAP were optimized and IgE obtained with natural rubber latex, obeche wood, wheat and rye flour Streptavidin ImmunoCAP were compared with the results of ImmunoCAP and Enzyme Allergo-Sorbent Test (EAST) using sera from patients complaining of workplace-related respiratory symptoms.


RESULTS
While the relation of biotin-label and protein was critical (best results were obtained with a 5- fold molar excess), labelled protein for coupling to streptavidin ImmunoCAP was applicable in a wide concentration range. On average, IgE values with streptavidin ImmunoCAP were as high as with ImmunoCAP but considerably higher than values obtained by EAST.


CONCLUSIONS
Streptavidin ImmunoCAP is a valuable tool for sensitive and specific measurement of IgE binding to new allergens superior to cellulose disk-based methods.
Sander
Ingrid
I
Research Institute for Occupational Medicine of the Berufsgenossenschaften (BGFA), Institute of the Ruhr University of Bochum, Bochum, Germany. sander@bgfa.ruhr-uni-bochum.de
Kespohl
Sabine
S
Merget
Rolf
R
Goldscheid
Natascha
N
Degens
Paul Otto
PO
Bruning
Thomas
T
Raulf-Heimsoth
Monika
M
D000485:Allergens / Q000276:immunology*; D019921:Biotinylation; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood* / Q000276:immunology; D007159:Immunologic Tests / Q000379:methods*; D011933:Reagent Kits, Diagnostic; D019809:Streptavidin
D000485:Allergens; D011933:Reagent Kits, Diagnostic; D007073:Immunoglobulin E; D019809:Streptavidin