TITLE:
Development of time-resolved immunofluorometric assays for the detection of house dust mite-allergic IgE in human sera
AUTHORS:
Ratchanoo Phiphatchaipaisarn, Jundee Rabablert, Kornkarn Bramarapravati, Duangthep Thongdee, Nares Wongpitoon, Worawan Durongpisitkul, Nat Malainual
KEYWORDS:
House Dust Mites; Time-Resolved Immunofluorometric Assay; Allergy; IgE
JOURNAL NAME:
Health,
Vol.2 No.11,
November
19,
2010
ABSTRACT: Dermatophagoides farinae and D. pteronyssinus are the prevalent house dust mites (HDM) in tropical countries and are associated with allergic diseases. This investigation developed a time- resolved immunofluorometric assay (TR-IFMA) for the first time to detect specific IgE antibody in patients with skin prick test positive to HDM but no detectable IgE by other means. Levels of IgE to natural and recombinant HDM allergens were measured by TR-IFMA in 50 HDM-allergic patients and 19 healthy participants compared to sandwich enzyme-linked immunosorbent assay (ELISA). A recombinant allergen, rDerf2, showed a 14 kDa band corresponding to broad range proteins of natural HDM.TR-IFMA showed sensitivity lower than 0.35 kUA/l. TR-IFMA employing three HDM antigens showed good correlations with sandwich ELISA at R2 0.93-0.96. TR-IFMA detected HDM IgE in 62, 62, 25 percent of allergic patient serum sample compared to 28, 32, and 22 percent detected by ELISA result using three HDM allergen. TR-IFMA also detected 26.3, 31.6, and 5.3 percent positive samples from 19 healthy participants while ELISA showed 0, 5.3, and 0 percents IgE positive samples. The use of rDerf2 as an HDM allergen for the assay was verified with no statistically different from other HDM allergens. TR-IFMA showed lower detection limit than ELISA and yielded higher sensitivity for serum of people with allergic symptoms with no detectable HDM IgE. It is anticipated that TR-IFMA for HDM-specific IgE detection will play an important role in future diagnosis of HDM allergy in clinical laboratories and for different research purposes.