Methods: 200 Der p-positive and 20 Der p-negative subjects were tested for serum immunoglobulin E (sIgE) against Der p 1, Der p 2, and Der p 10 using ImmunoCAP 100. 75 poly-sensitized patients were further examined with ImmunoCAP Immuno Solid-Phase Allergen Chip (ISAC). Der p 10-positive subjects were tested further for sIgE to crude extracts of cockroach, moth, and shrimp.
Results: 91.5% (183/200) patients were sensitized to Der p 1 and/or Der p 2. 6%(12/200) Der p-positive patients were sensitized to Der p 10. The positive proportion and median level of sIgE against Der p 1 were higher in children than in adults. Der p 1 and Der 2 correlated with Der p in sIgE levels (r=0.862, 0.799, P<0.001). ImmunoCAP ISAC demonstrated 100% specificity and 84% sensitivity in detecting Der p 1, p 2, and p 10 compared to ImmunoCAP 100. According to ImmunoCAP ISAC, 8 of these 12 Der p 10-positive patients were triple positive and 3 patients were triple negative to Pen m 1, Bla g 7, and Ani s 3; one was solely positive to Pen m1. Sensitization to Der p 10 correlated well with sIgE to shrimp, moths, cockroaches, Pen m 1, Bla g 7, and Ani s 3.
Conclusions: The detection of Der p 1 and Der p 2 well reflected atopy to Der p in a Chinese cohort. Sensitization to Der p 10 may result from cross-reactivity to seafood and cockroaches in coastal southern China. ImmunoCAP ISAC may offer a useful tool for CRD with performance comparable to ImmunoCAP 100.