Lock R J, Unsworth D J
Department of Immunology, Southmead Hospital, Westbury-on-Trym, Bristol, United Kingdom.
J Pediatr Gastroenterol Nutr. 1999 Jan;28(1):81-3. doi: 10.1097/00005176-199901000-00018.
Immunoglobulin A deficiency is more common in patients with coeliac disease and also in patients with other gastrointestinal diseases than in normal people. There is a concern, therefore, that routine serum immunoglobulin (Ig) A testing of all cases of suspected coeliac disease may lead to unnecessary biopsy.
Four hundred eighty-two routine consecutive samples from cases of suspected coeliac disease or malabsorption (109 children) were tested for IgA anti-endomysium and total IgA. Four hundred twenty-four sera samples also had IgG antigliadin checked for high-titre antibody. Archived adult sera from 31 patients with coeliac disease and 52 disease control subjects were included in the study.
Seven routine cases with serum IgA less than 15% of the mean normal for age and four cases with undetectable IgA were identified. Four patients, including three of four with clear deficiency, underwent small bowel biopsy, and all four had normal histologic findings and normal intraepithelial lymphocyte counts. Only one of the seven had high-titre IgG antigliadin antibody but that patient had normal histologic findings. One (3%) of 31 adults with established coeliac disease and 1 (2%) of 52 control subjects were IgA deficient.
Of patients with IgA deficiency, only those with both IgA deficiency and high-titre IgG antigliadin antibody should be routinely considered for biopsy.
免疫球蛋白A缺乏症在乳糜泻患者以及其他胃肠道疾病患者中比在正常人中更为常见。因此，有人担心对所有疑似乳糜泻病例进行常规血清免疫球蛋白（Ig）A检测可能会导致不必要的活检。
对482例疑似乳糜泻或吸收不良病例（109例儿童）的连续常规样本进行IgA抗肌内膜和总IgA检测。424份血清样本还检测了IgG抗麦胶蛋白的高滴度抗体。研究纳入了31例乳糜泻患者和52例疾病对照者的存档成人血清。
确定了7例血清IgA低于年龄正常均值15%的常规病例和4例IgA检测不到的病例。4例患者，包括4例中3例有明确缺乏的患者，接受了小肠活检，所有4例组织学检查结果均正常，上皮内淋巴细胞计数也正常。7例中只有1例有高滴度IgG抗麦胶蛋白抗体，但该患者组织学检查结果正常。31例确诊乳糜泻的成人中有1例（3%）IgA缺乏，52例对照者中有1例（2%）IgA缺乏。
对于IgA缺乏的患者，只有那些同时存在IgA缺乏和高滴度IgG抗麦胶蛋白抗体的患者才应常规考虑进行活检。
