Enzyme-linked immunosorbent assay for measurement of allergen-specific IgE antibodies in canine serum.

A micro-ELISA, using horseradish peroxidase-conjugated anti-canine IgE and polystyrene microtitration wells for detection of allergen-specific IgE in canine serum, was developed. Specificity of anti-canine IgE was confirmed by reversed cutaneous anaphylaxis evaluations, gel-precipitation reactions, immunoelectrophoresis, immunoaffinity chromatography, and heat inactivation. Individual allergen blanks were used to account for variable nonspecific binding among various allergens, and results were normalized using 4 reference sera. Coefficients of variation for intra-assay and interassay variability ranged from 0.77 to 5.66% and 3.15 to 9.83%, respectively. Results observed with wells coated with mixtures of various allergen extracts yielded results approximately equal to results (average) of wells containing individual components. Agreement between ELISA and skin test results ranged from 43 to 64%, depending on allergen used.

Effect of immunotherapy on the serum concentrations of allergen-specific IgG antibodies in dog sera.

An ELISA assay which uses horseradish peroxidase conjugated anti-canine IgG and polystyrene microtiter wells for detection of allergen-specific IgG in the serum of dogs is described. Individual allergen blanks were used to account for the variable nonspecific binding among various allergens, and the results observed in milliunits of absorbance were normalized using four reference sera. The coefficients of variation for the intraassay and interassay variability ranged from 1.34 to 12.50% and 4.62 to 9.77%, respectively. The relationship between ELISA results and serum concentrations of allergen-specific IgG was quantified. IgG antibodies with specificity for various allergens were found in the majority of non-atopic individuals and in all atopic subjects. Specific immunotherapy resulted in a rise in the serum concentration of allergen-specific IgG.