Tovey E R, Sluyter R, Duffy D L, Britton W J
Department of Medicine, University of Sydney, NSW, Australia.
J Allergy Clin Immunol. 1998 Apr;101(4 Pt 1):491-7. doi: 10.1016/s0091-6749(98)70356-2.
Although some studies have shown genetic control of specific IgE responses to purified grass allergens, studies with other allergens have not supported this. The extent of such control for house dust mite (HDM) (Dermatophagoides pteronyssinus) allergens is unclear.
We sought to determine the extent to which genetic factors control the specificity of IgE responses to individual HDM allergens by comparing the immunoblot patterns of IgE binding of serum from monozygotic and dizygotic members of a large cohort of Australian twins.
HDM proteins separated by sodium dodecylsulfate-polyacrylamide gel electrophoresis were immunoblotted with sera from 317 twin pairs in which at least one twin had at least a weak HDM skin test response. Concordance levels for IgE binding to the individual HDM components were compared in the subset of 142 pairs of twins in which both twins were allergic to HDMs (skin prick test wheal diameter, > 3 mm).
Over all 36 blotted bands, the mean case-wise concordance was 41% for monozygotic twins and 17% for dizygotic twins. Of the components detected, only those of molecular weights 23 kd and 16 kd were significantly different between the groups (p < 0.01). Differences observed between the monozygotic and dizygotic twins could be partly explained by overall IgE hyperresponsiveness.
Evidence for genetic control of IgE responses to 36 IgE-binding HDM components from a large sample of twins showed significant differences in concordance for two components and nonsignificant differences for several others. In the monozygotic twins, concordance never exceeded 67% for any band, and most monozygotic individuals recognized components their co-twin did not. Genetic control of overall atopy in monozygotic twins is far stronger than that controlling specific sensitization to HDM allergens.
尽管一些研究表明对纯化草类过敏原的特异性IgE反应存在基因控制，但针对其他过敏原的研究并未证实这一点。对于屋尘螨（HDM）（粉尘螨）过敏原而言，这种控制的程度尚不清楚。
我们试图通过比较澳大利亚一大群双胞胎中同卵和异卵成员血清IgE结合的免疫印迹模式，来确定基因因素对个体HDM过敏原IgE反应特异性的控制程度。
通过十二烷基硫酸钠 - 聚丙烯酰胺凝胶电泳分离的HDM蛋白，与来自317对双胞胎的血清进行免疫印迹，其中至少有一名双胞胎至少有弱阳性的HDM皮肤试验反应。在142对双胞胎的子集中比较了IgE与个体HDM成分结合的一致性水平，这142对双胞胎均对HDM过敏（皮肤点刺试验风团直径> 3 mm）。
在所有36条印迹条带中，同卵双胞胎的平均逐例一致性为41%，异卵双胞胎为17%。在检测到的成分中，只有分子量为23 kd和16 kd的成分在两组之间存在显著差异（p < 0.01）。同卵和异卵双胞胎之间观察到的差异部分可以用总体IgE高反应性来解释。
对大量双胞胎样本中36种IgE结合HDM成分的IgE反应进行基因控制的证据表明，两种成分的一致性存在显著差异，其他几种成分的差异不显著。在同卵双胞胎中，任何条带的一致性从未超过67%，而且大多数同卵个体识别出其双胞胎未识别的成分。同卵双胞胎中总体特应性的基因控制远强于对HDM过敏原特异性致敏的控制。
