Development of a light-initiated chemiluminescence assay for the quantitative detection of cow's milk allergen-specific IgE.

BACKGROUND

Cow's milk allergy is a common food allergy in children. Clinically, cow's milk-specific IgE (CM-sIgE) antibody test is often used to diagnose milk allergy. An inexpensive light-initiated chemiluminescence assay (LICA), with fast detection speed and small sample volume demand, has application prospects in the field of quantitative detection of CM-sIgE.

METHODS

Chemibeads coated with five major milk allergens, serum samples, biotinylated anti-human IgE antibodies, and streptavidin-coated sensibeads constitute a system to establish a LICA method for the quantitative detection of CM-sIgE. A series of experiments were performed to optimize its reaction conditions and evaluated its performance.

RESULTS

The optimal conditions for LICA were 10:4 mass ratio of chemibeads to milk allergen, 20 μg/mL chemibeads, 1.0 μg/mL biotinylated anti-human IgE antibodies and a 1/10 dilution of serum for 30-min incubation. The limit of Quantitation (LoQ) was 0.22 kU/L. For repeatability, the CV ranged from 3.71% to 8.11%. For intermediate precision, the CV ranged from 4.08% to 14.71%. It was linear within 0.20-18.20 kU/L. This method did not interfere with common interfering substances and total IgE in serum, and there was no obvious cross-reaction with milk-specific IgG and non-milk-specific IgE.

CONCLUSION

We have established a method to quantitatively detect CM-sIgE based on light-initiated chemiluminescence assay, which has good analytical performance and could meet the needs of clinical laboratories.