Picarelli A, di Tola M, Sabbatella L, Mastracchio A, Trecca A, Gabrielli F, di Cello T, Anania M C, Torsoli A
Department of Clinical Sciences, University of Rome La Sapienza, Rome, Italy.
J Intern Med. 2001 Feb;249(2):181-8. doi: 10.1046/j.1365-2796.2001.00793.x.
The aim of the present study was to increase the sensitivity of the antiendomysial antibody (EMA) test by evaluating also EMAs of IgG1 isotype.
Over the last 2 years, serum EMAs IgA and IgG1 were determined in 1399 patients, referred to our gastrointestinal unit due to clinical suspicion of malabsorption. Serum anti-tissue transglutaminase (tTG) antibodies IgA and IgG, as well as total IgA levels, were also investigated. Furthermore, EMAs IgA and IgG1 were evaluated in biopsy culture supernatants. Biopsy specimens were also admitted to histological and immunohistochemical evaluation. Twenty-six patients with gastroenterological disease other than coeliac disease (CD) were used as a disease control group. Ninety-nine blood donors were used as a healthy control group.
Diagnosis of CD was based on histological findings in the 110/1399 patients showing EMA IgA positivity, and in a further 56/1399 patients presenting both EMA IgA and IgG1 positivity in sera as well as in culture supernatants. Of the remaining 1233 EMA IgA-negative patients, 60 showed only EMA IgG1 positivity both in sera and in culture supernatants. It is noteworthy that anti-tissue transglutaminase antibodies IgG (anti-tTG) were positive in all 60 EMA IgG1-positive patients as well. By contrast, a selective IgA deficiency was found in only 11 out of the 60 EMA IgG1-positive patients. Villous height/crypt depth ratio was < 3:1 in 38 of the 60 EMA IgG1-positive patients (63.3%), whilst overexpression of ICAM-1 and CD25 was observed in all these patients.
In this study, we observed a group of CD patients who were EMA IgG1-positive even in the absence of EMA IgA positivity and IgA deficiency. The diagnosis was based on the finding of the gluten-dependent clinical and histological features typical of CD. Data emerging from the present investigation thus suggest that the prevalence of CD should be reassessed and that the determination of EMA IgG1 could offer a new tool in the diagnostic armamentarium of CD.
本研究的目的是通过评估IgG1同型的抗肌内膜抗体（EMA）来提高EMA检测的敏感性。
在过去2年中，对1399例因临床怀疑吸收不良而转诊至我们胃肠科的患者测定了血清EMA IgA和IgG1。还检测了血清抗组织转谷氨酰胺酶（tTG）抗体IgA和IgG以及总IgA水平。此外，对活检培养上清液中的EMA IgA和IgG1进行了评估。活检标本也进行了组织学和免疫组织化学评估。26例患有除乳糜泻（CD）以外的胃肠疾病的患者作为疾病对照组。99名献血者作为健康对照组。
110/1399例患者的诊断基于组织学检查结果显示EMA IgA阳性，另有56/1399例患者血清及培养上清液中EMA IgA和IgG1均阳性。在其余1233例EMA IgA阴性患者中，60例血清及培养上清液中仅显示EMA IgG1阳性。值得注意的是，所有60例EMA IgG1阳性患者的抗组织转谷氨酰胺酶抗体IgG（抗tTG）也均为阳性。相比之下，60例EMA IgG1阳性患者中仅11例发现选择性IgA缺乏。60例EMA IgG1阳性患者中有38例（63.3%）绒毛高度/隐窝深度比值<3:1，而所有这些患者均观察到细胞间黏附分子-1（ICAM-1）和CD25的过表达。
在本研究中，我们观察到一组即使在没有EMA IgA阳性和IgA缺乏的情况下EMA IgG1也呈阳性的CD患者。诊断基于发现CD典型的麸质依赖性临床和组织学特征。因此，本研究得出的数据表明，CD的患病率应重新评估，并且EMA IgG1的测定可为CD的诊断提供一种新工具。
