Comparison of the MAST chemiluminescent assay system with RAST and skin tests in allergic children.

The MAST chemiluminescent assay (CLA) system uses enzyme-linked antihuman IgE and a chemiluminogenic substance to determine specific IgE antibodies. The MAST CLA system therefore not only makes unnecessary the precautions required for handling isotopic materials but has the advantage of long-term reagent stability. The MAST CLA system assay protocol consists of three steps: overnight incubation of serum, a 4-hour incubation with enzyme-labeled antibody, and a 30-minute chemiluminescent reaction, which produces a visible image (immunograph) on high-speed instant Polaroid film. We evaluated this MAST CLA system in 47 allergic children and compared the results with those for RAST and skin tests. Good correlations were found between MAST and RAST for house dust, Dermatophagoides farinae, cat, Japanese cedar pollen, egg white, and soybeans, the correlation coefficients being greater than 0.60. When the diagnostic results for MAST and RAST were compared with those of skin test reactions for house dust, Dermatophagoides farinae, cat, Japanese cedar pollen, egg white, and soybeans, MAST had a sensitivity of 85% and a specificity of 82% as compared with 88% and 83% for RAST. Further, an average of 2.1 different allergens were detected in one serum sample. These results suggest that the MAST CLA system can be used to detect specific IgE antibodies and that it provides accurate results for allergic children.