IgA Anti-Tissue Transglutaminase Antibodies, First Line in the Diagnosis of Celiac Disease

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 investigated 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 predictive value 55.2 %, specificity 93.1 %, negative predictive value 973 %, 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 mellitus (235 % 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)