特应性皮炎婴幼儿免疫球蛋白E介导特异性免疫功能与体液免疫状态的特点及临床意义

摘要

目的 探讨特应性皮炎(AD)婴幼儿免疫球蛋白(Ig)E介导特异性免疫功能与体液免疫状态的特点及临床意义.方法 选取2013年2月至2014年2月空军总医院55例临床确诊的AD患儿,年龄0.5 ～2.7岁、平均(1.2±0.2)岁,男、女分别29、26例,另纳入同期28例同龄健康儿童作为对照.采用酶联免疫吸附试验检测血清IgG、IgM、IgA水平,另采用蛋白质印迹方法经德国敏筛定量过敏原检测系统检测血清中食物过敏原、吸入性过敏原的特异性IgE(sIgE)水平.结果 AD患儿血清IgG、IgA水平低于正常儿童,差异有统计学意义[(5.15±0.65) g/L比(7.70±0.72) g/L、(0.38±0.10) g/L比(0.43 ±0.12) g/L,P＜0.05];血清IgM水平为[(0.51±0.18)g/L],与正常儿童[(0.48 ±0.11) g/L]差异无统计学意义(P＞0.05).AD患儿食物过敏原sIgE的总阳性率为36.4％(20/55)、主要食物过敏原为牛奶[21.8％(12/55)]、鸡蛋[18.2％ (10/55)];吸入性过敏原sIgE的总阳性率为25.5％(14/55),主要过敏原为尘螨[16.4％ (9/55)].6～12月龄AD婴儿食物过敏原sIgE阳性率高于而吸入性过敏原sIgE阳性率低于12月龄以上AD患儿,差异均有统计学意义[70.0％(14/20)比30.0(6/20),21.4(3/14)比78.6％(11/14),均P＜0.05].结论 AD婴幼儿存在不同程度免疫功能异常,IgE介导特异性免疫反应过强,食物过敏原、吸入性过敏原诱发的IgE介导的过敏反应是婴幼儿发生AD的重要原因,尤以食物过敏原更为明显,年龄越小越以食物过敏原为主要诱因,随着年龄增长吸入性过敏原致敏的几率逐渐增加;同时AD婴幼儿又存在不同程度特异性体液免疫功能低下,其中以血清IgG、IgA水平降低更为明显.%Objective To investigate the characteristics and clinical significance of immunoglobulin (Ig)E-mediated specific immune function and humoral immune function in infants with atopic dermatitis (AD).Methods Totally 55 AD infants from 6 months to 2.7 years (29 boys and 26 girls) from February 2013 to February 2014 were enrolled (AD group);28 healthy infants of the same age at the same period were set as control group.Enzyme-linked immunosorbent assay method was used to detect the levels of serum IgG,IgM and IgA;the specific IgE (sIgE) of food and inhaled allergen in serum were measured with Mediwiss Analytic GmbH.Results The levels of IgG,IgA in AD group were significantly lower than that in control group [(5.15 ±0.65) g/L vs (7.70 ± 0.72) g/L,(0.38 ± 0.10) g/L vs (0.43 ± 0.12) g/L,P ＜ 0.05];the level of IgM was not significantly different between groups [(0.51 ± 0.18) g/L vs (0.48 ± 0.11) g/L] (P ＞ 0.05).The positive rate of food allergen sIgE was 36.4％ (20/55),the mainly allergen included milk [21.8 (12/55)] and egg [18.2％ (10/55)];the positive rate of inhaled allergen sIgE was 25.5％ (14/55),the main allergen included dust mites [16.4％ (9/55)].The positive rate of food allergen-sIgE was significantly higher,the positive rate of inhaled allergen-specific IgE was significantly lower in AD infants aged 6-12 months than those in AD infants aged ＞12 months [70.0％ (14/20)vs30.0％ (6/20),21.4％ (3/14)vs78.6％ (11/14)] (P＜0.05).Conclusions The immune function is abnormal in infant AD,in that IgE-mediated specific immune reaction increases;food allergen and inhaled allergen,especially food allergen induced IgE mediated anaphylaxis is the important cause of infant AD;the more younger,the more higher sensitivity to food allergens,and the inhaled allergen induced AD increases with age;hypofunction of humoral immunity is also found in AD,in that the levels of IgG and IgA in serum are significantly decreased.