Detection of Serum IgE Specific to Mite Allergens by Immuno-PCR

Background: Although a skin test is the primary option for detecting allergen-specific IgE in clinics, the serum IgE immunoassay is also important because it allows for the diagnosis of allergy without any accompanying adverse effect on the patient. However, the low detection limit of IgE levels by immunoassay may restrict the use of the method in some occasions, and improving its sensitivity would thus have a significant implication in allergy-immunology clinics. Methods: In this study, we attempted to detect specific serum IgE by using immuno-polymerase chain reaction (IPCR) which combines the antigen-antibody specificity of enzyme-linked immunosorbent assays (ELISAs) with the amplification power of PCR. Results: Our results demonstrated that Blo t5-specific serum IgE can be detected by IPCR with a 100-fold higher sensitivity than ELISA, and cross-reactivity of serum IgE to other mite allergens is able to be analyzed by using only $0.3{\mu}l$ of serum sample. Use of real-time IPCR seemed to permit more convenient determination of specific serum IgE as well. Conclusion: We believe that IPCR can serve as a valuable tool in determining specific serum IgE, especially when the amount of serum sample is limited.