CCD contributes for cross-reactivity between food allergen and Bermuda and Timothy pollen allergen in Southern China

Background: We tried to use allergen molecular microarray to investigate the distribution of pollen allergens in southern China. Method: 80 cases from 23 cities in southern China with two or more allergens sIgE-positive were selected for testing sIgE of 28 pollen components with ISAC. In addition, we selected another 57 bermuda sIgE-positive patients to further test serum sIgE of allergen and components by ImmunoCAP. Results: 1.In 80 selected patients, 32% patients were positive to pollen allergen. 16% were IgE positive to Cyn d 1 (bermuda), 15% to Phl p 4, 4% to Phl p 1, 1% to Phl p 5 (timothy), 11% to Pla a 2 (plane tree). There were 8% with CCD sIgE positive. 2.In 57 patients who sensitized to bermuda grass extract, 54% were positive to Cyn d 1, while 58% were positive to timothy and 61% to Phl p 4, 11% to Phl p 1, 71% to peanut , 53% positive to soy. 3.The sIgE levels were good correlations between timothy and Phl p 4 (r=0.87), bermuda and Cyn d 1 (r=0.60). Phl p 4 correlated well with bermuda (0.63), Cyn d 1 (r=0.88), soy (r=0.86), and peanut (r=0.77) and with CCD sIgE (r=0.74). Conclusion: The most important pollen allergens in southern China are bermuda and timothy and plane tree pollen. In China most pollen allergy patients are multi-sensitized. This study clearly confirms that Cyn d 1 is the main component of bermuda. Phl p 4 was more likely to be identified in patients sensitized to timothy extract, and it correlated well with CCD and other pollen allergen and plant food allergen, which indicated there may be cross-reactivity between the pollen allergens and plant food allergens, for presenting the same antigen epitope with CCD.