食物特异性IgG抗体检测在儿童慢性腹泻中的应用价值

目的：儿童慢性腹泻病因复杂，难以明确病因,常给治疗带来很大困难，目前认为食物过敏可能是儿童慢性腹泻的重要病因，特别是IgG介导的迟发型变态反应起主要作用。该文就食物特异性IgG与儿童慢性腹泻的相关性进行分析研究，探讨食物特异性IgG检测对儿童慢性腹泻病因诊断和治疗的价值。方法：采用ELISA法，检测患儿血清中食物特异性IgG抗体浓度，根据IgG浓度分为4级：0级，+1级，+2级，+3级。其中 0级采取“安全进食”, +1级采取“轮替”进食,+2级、+3级采取“忌食”的健康饮食指导，并观察患儿腹泻症状改善情况。结果：82例慢性腹泻患儿中，79例有1~11种不等的食物特异性IgG升高，阳性率96.2%，而对照组阳性率仅为26.7%,慢性腹泻组中对2~5种食物过敏的比例最高占58.5%。其中对牛奶、蛋清/黄敏感性最高，分别为68.3%、62.2%，而针对鸡肉和猪肉的特异性IgG升高者较少，分别为2.4%和0%。79.3%病人经过健康饮食指导治疗后疗效显著。17例（20.7%）病人症状在3个月内无明显缓解，其中5例大便培养有细菌感染，6例家属或患儿未严格执行健康饮食指导，6例原因不明。结论：食物过敏是引起儿童慢性腹泻的重要原因，根据食物特异性IgG抗体检测结果对患儿进行健康饮食指导是治疗儿童过敏性慢性腹泻的最好方法。

Application of food allergens specific IgG antibody detection in chronic diarrhea in children

Objective The causes of chronic diarrhea in children are complex. At present, food allergy is generally viewed as an important cause of this disorder, and IgG-mediated delayed allergy plays a major role in this process. This study aimed to explore the link between food specific IgG and chronic diarrhea in children, as well as the value of food allergens-specific IgG antibody detection in the management of this disorder.Methods Eighty-two children with chronic diarrhea and 30 healthy controls were enrolled. Serum levels of specific IgG antibody to 14 kinds of food were detected using ELISA. The results were classified into four grades: Grade 0 (negative), Grade 1 (mild allergy), Grade 2 (moderate allergy) and Grade 3 (severe allergy). The patients received a diet treatment based on the results of food specific IgG antibody detection. Children with negative IgG antibody were allowed to continue their current diet. In children with Grade 1 allergy, the food responsible for the IgG antibody positive test was given only at an interval of four days. In children with Grade 2 or 3, the offending food was eliminated from the diet. Results Of the 82 children with chronic diarrhea, 79 (96.2%) had increased specific IgG levels for one or more of the 14 foods tested compared to 8 (26.7%) of the controls (P<0.01). The majority of patients showed increased specific IgG levels for milk (68.3%) and egg (62.2%). A low proportion of patients (2.4%) was allergic to chicken, and no patient was allergic to pork. The symptoms were improved in 65 patients (79.3%) after 1 week to 3 months of diet treatment.Conclusions Food allergy is one of major causes of chronic childhood diarrhea. Food specific IgG antibody detection may assist in the dietary management of this disorder.