Clin. Lab. 2011;57:695-701 ©Copyright ORIGINAL ARTICLE IgA Anti-Tissue Transglutaminase Antibodies, First Line in the Diagnosis of Celiac Disease GABRIEL SAMAŞCA 1 , MIHAELA IANCU 2 , DORIN FARCĂU 3 , ANGELA BUTNARIU 3 , TUDOR POP 4 , ALEXANDRU PÎRVAN 4 , MARIANA ANDREICA 4 , NICOLAE MIU 4 , VICTOR CRISTEA 1 , DORU DEJICA 1 1 Department of Immunopathology, ”Iuliu Haţieganu” University of Medicine and Pharmacy Cluj-Napoca, Romania 2 Department of Medical Informatics and Biostatistics, ”Iuliu Haţieganu” University of Medicine and Pharmacy Cluj-Napoca, Romania 3 Department of Pediatrics III, ”Iuliu Haţieganu” University of Medicine and Pharmacy Cluj-Napoca, Romania 4 Department of Pediatrics II, ”Iuliu Haţieganu” University of Medicine and Pharmacy Cluj-Napoca, Romania SUMMARY Background: According to the 2008 celiac disease working group run by Dr. A. Fassano under the auspices of the Federation of International Societies of Pediatric Gastroenterology, Hepatology and Nutrition, celiac disease is a chronic immune-mediated enteropathy characterized by gluten sensitivity, which can affect any organ or system, having a wide range of clinical manifestations of variable severity. The serological diagnosis of celiac disease is based on high sensitivity and specificity tests. The measurement of IgA anti-tissue transglutaminase antibodies by ELISA is universally accepted in the screening of celiac disease. Methods: Using the gold standard represented by IgA anti-endomysium antibodies in a group of 890 children in- vestigated during 2008-2009, we aimed to evaluate IgA anti-tissue transglutaminase antibodies (tTG IgA), as well as to establish their prevalence in associated diseases. Results: Following the measurement of tTG IgA in the entire group, we obtained: sensitivity 77.3 %, positive pre- dictive value 55.2 %, specificity 93.1 %, negative predictive value 97.3 %, p = 0.000, and in tTG IgA associations we obtained the value 0.51 for the ROC curve area. We found associations of tTG IgA with type 1 diabetes melli- tus (2.35 % prevalence), protein-calorie malnutrition (0.89 % prevalence), and intestinal malabsorption (0.56 % prevalence). Conclusions: Our results have a high specificity and sensitivity in the screening of celiac disease, while requiring a second method of confirmation. (Clin. Lab. 2011;57:695-701) KEY WORDS Celiac disease, IgA anti-tissue transglutaminase anti- bodies, associated diseases INTRODUCTION In 2004, the National Public Health Institute of USA re- commended the standardization of serological tests and pathological criteria for the diagnosis of celiac disease (1). Since then, serological tests have played a special role in the diagnosis of celiac disease (2), as well as in its possible associations (3-4). In 2008, the European Society of Pediatric Gastroen- terology, Hepatology and Nutrition together with the North American Society of Pediatric Gastroenterology, Hepatology and Nutrition issued a consensus statement on celiac disease (5), which showed the following: I. Celiac disease is a chronic immune-mediated entero- pathy characterized by gluten sensitivity, which can af- fect any organ or system, having a wide range of clini- cal manifestations of variable severity; II. The serological diagnosis of celiac disease is based on two high sensitivity and specificity immunological tests, i.e. IgA anti-endomysium antibodies (EmA IgA) _____________________________________________ Manuscript accepted February 12, 2011 Clin. Lab. 9+10/2011 695