Proficiency monitoring of monoclonal antibody cocktail-based enzyme-linked immunosorbent assay for detection of allergen-specific immunoglobulin E in dogs.

The purpose of our study was to document the continued comparative proficiency of different laboratories that perform a monoclonal antibody-based enzyme-linked immunosorbent assay (macELISA) for detection of allergen-specific immunoglobulin (Ig)E in dogs. Replicate samples of 18 different sera pools were independently evaluated in a single blinded fashion by each of 16 different operators functioning in 10 different laboratories. The average intra-assay variance among reactive assay calibrators in all laboratories was 6.0% (range: 2.7-16.1%), while the average intralaboratory interassay variance was 7.5% (range: 3.9-10.9%). The overall interassay interlaboratory variance was consistent among laboratories and averaged 11.4% (range: 8.5-12.5%). All laboratories yielded similar profiles and magnitudes of responses for replicate unknown samples; dose response profiles observed in each of the laboratories were indistinguishable. Considering the positive or negative results, interassay interlaboratory concordance of results exceeded 90%. Correlation of optical density values between and among all laboratories was strong (r > 0.9, P < 0.001). Collectively, the results demonstrated that the macELISA for measuring allergen-specific canine IgE is reproducible, and documents that consistency of results can be achieved not only in an individual laboratory by differing operators but also among laboratories using the same monoclonal-based ELISA.