NCCPA Ensuring Standards in the PA Profession Practice Test

In celiac disease, the standard approach is to start with a serologic screen using tissue transglutaminase IgA antibodies because this test has high sensitivity and specificity. If the serology is positive or if clinical suspicion remains high, the diagnosis is confirmed with an upper endoscopy and a small bowel biopsy showing villous atrophy with crypt hyperplasia and increased intraepithelial lymphocytes. It’s important to check total IgA because some individuals have IgA deficiency, which can cause a false-negative serology; in that case, IgG-based tests (such as tTG-IgG or DGP-IgG) are used. Genetic testing for HLA-DQ2/DQ8 can support risk assessment but is not diagnostic on its own since many people carry these haplotypes without disease. Other options like colonoscopy, ultrasound, or a gluten tolerance test do not provide the reliable serologic-to-biopsy pathway needed to diagnose celiac disease. The biopsy finding of villous atrophy is the key confirmatory detail.