Saarinen Kristiina Mertta, Sarnesto Annikki, Savilahti Erkki
Hospital for Children and Adolescents, University of Helsinki, Helsinki, Finland.
Pediatr Allergy Immunol. 2002 Jun;13(3):188-94. doi: 10.1034/j.1399-3038.2002.01027.x.
Growing evidence exists that exposure to cow's milk elicits inflammation in the gut of infants with cow's milk allergy, irrespective of symptoms. To demonstrate inflammation and increased protein leakage from the gut during a cow's milk elimination-challenge test in fecal samples of infants presenting with different symptoms suggestive of cow's milk allergy, we measured the concentrations of alpha1-antitrypsin (AT), eosinophil cationic protein (ECP), immunoglobulin (Ig) A, and cow's milk-specific IgA antibodies, in fecal samples of 208 infants with a mean age of 7 months. Prechallenge samples were collected after a mean 3-week elimination period, and post-challenge samples were obtained 4 days after starting the challenge. Fecal levels of prechallenge total IgA (p = 0.02) and post-challenge AT (p = 0.001) were higher in infants with a positive challenge. Of these infants, pre- and post-challenge levels of ECP were higher in those reacting after 24 h than in those reacting within 1 h (p = 0.006 and p = 0.045). Prechallenge levels of ECP were higher in those showing intestinal symptoms (p = 0.008), and both pre- and post-challenge levels of total IgA were higher in those with an IgE-mediated reaction to cow's milk (p = 0.04 and p = 0.008). Regardless of the challenge result, total IgA increased during the challenge (p < 0.001 for both challenge-positive and -negative infants) and was higher in those breast-fed until the challenge than in those fed formula only (p < 0.01). Hence, in infants reacting to the cow's milk challenge, higher prechallenge levels of fecal IgA indicate increased antigenic stimuli in the gut, and higher post-challenge levels of AT reflect increased protein loss as a result of intestinal inflammation. In infants with slowly evolving gastrointestinal symptoms, increased fecal ECP may help in distinguishing patients from those who tolerate cow's milk. Individual serial follow-up of fecal IgA and ECP can be used to estimate the degree of inflammation in the gut and an appropriate time for a challenge test, but are not diagnostic tools for cow's milk allergy.
越来越多的证据表明，接触牛奶会引发牛奶过敏婴儿肠道的炎症，无论有无症状。为了在表现出不同牛奶过敏症状的婴儿粪便样本的牛奶排除激发试验中证明肠道炎症和蛋白质渗漏增加，我们测量了208名平均年龄为7个月的婴儿粪便样本中α1-抗胰蛋白酶（AT）、嗜酸性粒细胞阳离子蛋白（ECP）、免疫球蛋白（Ig）A和牛奶特异性IgA抗体的浓度。激发前样本在平均3周的排除期后收集，激发后样本在开始激发4天后获得。激发阳性的婴儿激发前粪便总IgA水平（p = 0.02）和激发后AT水平（p = 0.001）更高。在这些婴儿中，24小时后有反应的婴儿激发前和激发后ECP水平高于1小时内有反应的婴儿（p = 0.006和p = 0.045）。有肠道症状的婴儿激发前ECP水平更高（p = 0.008），对牛奶有IgE介导反应的婴儿激发前和激发后粪便总IgA水平均更高（p = 0.04和p = 0.008）。无论激发结果如何，激发期间总IgA均增加（激发阳性和阴性婴儿p均<0.001），且在激发前一直母乳喂养的婴儿中高于仅喂配方奶的婴儿（p < 0.01）。因此，在对牛奶激发有反应的婴儿中，激发前粪便IgA水平较高表明肠道中抗原刺激增加，激发后AT水平较高反映了肠道炎症导致的蛋白质损失增加。在胃肠道症状发展缓慢的婴儿中，粪便ECP增加可能有助于将这些患者与耐受牛奶的患者区分开来。粪便IgA和ECP的个体连续随访可用于估计肠道炎症程度和激发试验的合适时间，但不是牛奶过敏的诊断工具。
