Indoor mite allergen levels, specific IgE prevalence and IgE cross-inhibition pattern among asthmatic children in Haikou, southern China / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Haikou locates in tropical island with unique mite propagation. The aim of this stuy is to determine mite allergens levels in Haikou, and to investigate the prevalence of mite specific IgE-sensitization and IgE cross-reactivity between house dust mites.</p><p><b>METHODS</b>Allergen and antigen concentrations against six mite species were tested by enzyme-linked immunosorbent assay (ELISA). Specific IgE concentrations and cross-inhibitions were measured with ADVIA Centaur(®).</p><p><b>RESULTS</b>Allergen or antigen Dermatophagoides pteronyssinus (Der p 1), Blomia tropicalis (Blo t) and Tyrophagus putrescentia (Tyr p) were detected in dust samples. Dermatophagoides farinae (Der f 1), Lepidoglyphus destructor (Lep d 2), and Acarus siro (Aca s) were found in very few samples. Specific IgE tests showed high prevalence of sensitizations against all tested mites with high IgE levels to Der p, Der f, and Blo t. Storage mites, Blo t, Tyr p, Lep d, and Aca s, could inhibit Der p from 0 to 50%. Storage mites could inhibit Der f between 30% and 100%. Der p IgE could be inhibited by Der f with up to 90%, and vice versa. Der p could inhibit Blo t from 40% to 80%. Blo t was able to fully inhibit IgE binding to Lep d, Tyr p, and Aca s compared to partial inhibition by Der p.</p><p><b>CONCLUSIONS</b>Der p is the dominating mite and has the highest specific IgE prevalence among asthmatic children. Blo t represents an important source of storage mite sensitization and some patients may be independently sensitized to both Der p and Blo t. High prevalence of sensitization to Der f may be due to IgE-mediated cross-reactivity with Der p and Blo t.</p>

Allergen micro-array detection of specific IgE-reactivity in Chinese allergy patients / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Allergen micro-arrays are powerful tools for screening of serum IgE-reactivity. In this study allergen micro-arrays were used to identify dominating IgE-binding allergens and cross-reactivity patterns among selected Chinese allergy patients.</p><p><b>METHODS</b>The study was conducted using patient sera from the cities of Guangzhou, Nanjing, Chengdu and Shenyang. In total 100 sera with Dermatophagoides pteronyssinus (Der p) specific IgE-levels higher than 50 kU/L were selected for testing against 103 individual allergens.</p><p><b>RESULTS</b>Among 100 selected patients, 95% showed IgE-reactivity towards house-dust mite allergens Dermatophagoides farinae (Der f) 1, Der f 2 and Der p 2 and 94% were IgE positive against Der p 1, and 60% of sera contained IgE reacting against allergen Euroglyphus maynei (Eur m) 2. IgE against cat allergen, Felisdomesticus (Fel d) 1, was seen in 20%. Only 2% showed specific IgE-reactivity to Der p 10, a panallergen belonging to the tropomyosin family. Serum IgE-reactivity towards other allergens was in general low. IgE-reactivity against pollen allergens showed geographic differences.</p><p><b>CONCLUSIONS</b>This study clearly confirms that group 1 and group 2 are major allergens of house dust mites. These selected house-dust mite allergy patients are close to being mono-sensitized. Der p 10 is not an important allergen for cross-reactivity. Specific IgE-sensitization towards pollen allergens is low in southern China compared to other regions. The prevalence of food and stinging insect allergens known to give rise to IgE-mediated cross-reactivity is 2% or less.</p>