Celiac Disease Laboratory Testing (CPB 0561, reviewed 2026-08-03)
Serological testing for IgA anti-human tissue transglutaminase (TTG), IgG and IgA deamidated gliadin (DGP), and IgA anti-endomysial (EMA) antibodies is medically necessary as a preliminary diagnostic test for persons with symptoms suggestive of celiac disease, to monitor response to a gluten-free diet, to screen first-degree relatives of individuals with celiac disease, and to screen persons with type 1 diabetes. HLA-DQ2 and HLA-DQ8 genetic testing is medically necessary for listed situations, including seronegative persons with equivocal small bowel histology findings (Marsh I-II), evaluation of persons on a gluten-free diet in whom no serologic testing was performed before starting it, and persons with Down syndrome. Anti-gliadin antibody (AGA) and anti-reticulin antibody (ARA) testing, the Prometheus Celiac Plus Panel, and HLA genotyping for screening persons with type 1 diabetes are experimental, investigational, or unproven.