Kuo I Chun, Cheong Nge, Trakultivakorn Muthita, Lee Bee Wah, Chua Kaw Yan
Department of Paediatrics, Faculty of Medicine, National University of Singapore.
J Allergy Clin Immunol. 2003 Mar;111(3):603-9. doi: 10.1067/mai.2003.167.
Dual sensitization by Blomia tropicalis and Dermatophagoides pteronyssinus mites is common in tropical and subtropical countries. The human IgE cross-reactivity between clinical important group 5 allergens, Blo t 5 and Der p 5, remains controversial.
This study was undertaken to assess the levels of the IgE cross-reactivity between Blo t 5 and Der p 5 by using sera from a large cohort of asthmatic children in subtropical and tropical countries.
Purified recombinant Blo t 5 and Der p 5 were produced in Pichia pastoris and tested against sera from 195 asthmatic children. The IgE cross-reactivity was examined by direct, inhibitory and competitive human IgE enzyme-linked immunosorbent assay as well as skin prick tests.
The Blo t 5 IgE responses were 91.8% (134 of 146) and 73.5% (36 of 49) for Taiwanese and Malaysian sera, respectively. The Blo t 5 specific IgE titers were significantly higher than those of Der p 5 (P <.02). The correlation of IgE reactivity between Blo t 5 and Der p 5 was low, and only limited cross-reactivity was observed. This was further confirmed by the dose-response inhibition studies. Skin prick tests performed on asthmatic children in Thailand also showed differential IgE response to Blo t 5 and Der p 5.
By using a large panel of asthmatic sera and a combination of in vitro and in vivo assays, the major allergen of B tropicalis in tropical and subtropical regions, Blo t 5, exhibits low levels of IgE cross-reactivity with homologous Der p 5. These findings suggest that highly specific clinical reagents are necessary for precise diagnosis and immunotherapeutic treatment of sensitization to group 5 mite allergens.
热带无爪螨和屋尘螨双重致敏在热带和亚热带国家很常见。临床上重要的第5组变应原Blo t 5和Der p 5之间的人IgE交叉反应性仍存在争议。
本研究旨在通过使用来自亚热带和热带国家一大群哮喘儿童的血清，评估Blo t 5和Der p 5之间的IgE交叉反应水平。
在毕赤酵母中生产纯化的重组Blo t 5和Der p 5，并对195名哮喘儿童的血清进行检测。通过直接、抑制和竞争性人IgE酶联免疫吸附试验以及皮肤点刺试验检测IgE交叉反应性。
台湾和马来西亚血清中Blo t 5的IgE反应率分别为91.8%（146例中的134例）和73.5%（49例中的36例）。Blo t 5特异性IgE滴度显著高于Der p 5（P<.02）。Blo t 5和Der p 5之间的IgE反应性相关性较低，仅观察到有限的交叉反应性。剂量反应抑制研究进一步证实了这一点。在泰国对哮喘儿童进行的皮肤点刺试验也显示了对Blo t 5和Der p 5的不同IgE反应。
通过使用大量哮喘血清以及体外和体内试验相结合的方法，热带和亚热带地区热带无爪螨的主要变应原Blo t 5与同源的Der p 5表现出低水平的IgE交叉反应性。这些发现表明，对于5组螨变应原致敏的精确诊断和免疫治疗，需要高度特异性的临床试剂。
