Ten Times Normal Anti Tissue Transglutaminase Level Detected By Enzyme Linked Immunosorbent Assay (ELISA), But Normal Level by Chemiluminescent Assay (CLIA)

According to the new guidelines of the European Society for Pediatric Gastroenterology Hepatology and Nutrition [1], it is mandatory to test for anti tissue transglutaminase IgA (anti TTG IgA) and serum IgA in first step in the diagnosis of celiac disease. A diagnosis of celiac disease can be made when the anti-TTG IgA titer is ten times normal (with normal Ig A level) and anti-endomysial antibody (EMA) is positive in the second blood sample, without requiring biopsy. In this article, we present cases of anti TTG IgA levels more than ten times the upper limit of normal determined by ELISA (enzyme-linked immunosorbent assay). In some patients, EMA was checked and in all of these cases upper endoscopy and duodenal biopsy was performed for confirmation, Although biopsy was performed from the bulb and the second part of the duodenum, and the number of biopsies were adequate; no evidence of celiac disease was observed on histological examination. These patients were recruited, and another blood sample was taken and anti TTG IgA was checked by a chemiluminescence immunoassay (CLIA) and the levels were reported normal.