Analysis of MAST Chemiluminescent Assay (MAST CLA) Results Performed in Asan Medical Center: Suggestion for the improvement of MAST CLA performance

Yang, Sung Eun; Oh, Heung Bum; Hong, Soo Jong; Moon, Dae Hyuk; Chi, Hyun Sook

Abstract

BACKGROUND: Multiple allergosorbent test chemiluminescent assay (MAST CLA) is a simple method for in vitro measurement of allergen-specific IgE antibodies. In the present study, the diagnostic performance of MAST CLA was evaluated from the data of Asan Medical Center.
METHODS
With the test results of Korea IgE Panel, Korean Food Panel and Korean Inhalant Panel, we evaluated the next following. First, the change of the positive rates of allergen-specific IgE antibodies after the Korea IgE panel was divided into each Food Panel and Inhalant Panel; Second, the diagnostic performance of total IgE determined by MAST CLA in comparison with those determined by RIA; Third, the discrepancy of reactive intensity in Food and Inhalant Panels tested with the same specimens; Fourth, the diagnostic performance of MAST CLA compared with RAST, in detecting the IgE antibodies to three most common allergens.
RESULTS
Overall positive rate was 33.9% (548/1,617); 39.3% for Korea IgE Panel, 22.9% for Food Panel, 34.6% for Inhalant Panel. Positive rate was increased only 0.5% for Food Panel and only 0.3% for Inhalant Panel by the new allergens added. The sensitivity, specificity, and concordance rate of total IgE levels determined by MAST CLA in comparison with those determined by RIA was 68.4%, 64.9%, 66.8% in Food Panel, and, 87.6%, 44.4%, 68.5% in Inhalant Panel. Five of the eighteen specimens tested by Food and Inhalant Panels simultaneously showed discrepant reactivity with the extent of class 1. The sensitivity, specificity, and concordance rate of MAST CLA compared with RAST were 36.1%, 100.0%, 67.1% for D. farinae, 30.8%, 96.8%, 60.6% for D. pteronyssinus, and 21.4%, 96.2%, 70.0% for housedust.
CONCLUSIONS
The allergens newly added to Food and Inhalant Panels were not contributable to the detection of allergen-specific IgE. The specificity of total IgE was so low that positive total IgE result without specific IgE should be interpreted as false positive. The sensitivity to common allergens was also too low. So, MAST CLA needs further improvement to be used as a primary screening test for allergy.