Sinclair David, Pearce Callum B, Saas Michael S L, Poller David
Department of Chemical Pathology, Queen Alexandra Hospital, Portsmouth PO6 3LY, UK.
Ann Clin Biochem. 2003 Jul;40(Pt 4):411-6. doi: 10.1258/000456303766477075.
The demand for screening for coeliac disease has grown rapidly over the last few years. Laboratories depending on immunofluorescence assays are faced with an increasing workload using a labour-intensive test, and an alternative to this test has been sought. This study compares tissue transglutaminase (TTG) and endomysium antibodies (EMA) in a routine clinical laboratory situation.
An immunofluorescence IgA EMA test was compared with a guinea pig TTG antibody ELISA for 816 unselected requests for gut antibody screening. Discrepant results were investigated more fully using a variety of human source TTG antigen kits.
Guinea pig TTG ELISA and EMA assays showed agreement for 93.6% of samples. Four samples were misclassified and 48 samples gave false positive TTG results. Study of 46 EMA samples (this group included 39 of the 'discrepant' negative EMA/positive guinea pig TTG group) using three different human purified and/or recombinant TTG sources showed that 42 patients had no TTG antibodies using human sources, three were misclassified and one patient had negative EMA and positive TTG results that could not be readily explained. Further study of 32 EMA positive samples showed almost complete agreement between the human source TTG kits.
We can recommend the replacement of EMA with ELISA for TTG antibodies for the routine screening for coeliac disease, but all positive TTG antibodies should still be followed up with IgA EMA and samples should be screened for IgA deficiency.
在过去几年中，对乳糜泻筛查的需求迅速增长。依赖免疫荧光检测的实验室面临着使用劳动密集型检测方法导致工作量不断增加的问题，因此一直在寻求该检测的替代方法。本研究在常规临床实验室环境中比较了组织转谷氨酰胺酶（TTG）和肌内膜抗体（EMA）。
将免疫荧光IgA EMA检测与豚鼠TTG抗体ELISA用于816例未经选择的肠道抗体筛查请求进行比较。使用多种人源TTG抗原试剂盒对不一致的结果进行了更全面的调查。
豚鼠TTG ELISA和EMA检测对93.6%的样本结果一致。4个样本分类错误，48个样本TTG结果呈假阳性。使用三种不同的人纯化和/或重组TTG来源对46个EMA样本（该组包括“不一致”的阴性EMA/阳性豚鼠TTG组中的39个）进行研究，结果显示42例患者用人源检测无TTG抗体，3例分类错误，1例患者EMA阴性而TTG结果阳性，原因难以解释。对32个EMA阳性样本的进一步研究表明，人源TTG试剂盒之间几乎完全一致。
我们建议在乳糜泻常规筛查中用ELISA检测TTG抗体替代EMA检测，但所有TTG抗体阳性结果仍应进一步检测IgA EMA，且应对样本进行IgA缺乏筛查。
