Commonly Used Diagnostic Tests for Celiac Disease Tissue transglutaminase (tTG) IgA antibodies - Most reliable noninvasive test and first-level screening test - High sensitivity and specificity - Falsely negative with IgA deficiency (3% of patients with celiac disease) - May be negative if on low-gluten diet Tissue transglutaminase (tTG) IgG antibodies - Useful in patients with IgA deficiency - Widely variable sensitivity and specificity IgA antiendomysial antibodies - May be useful in patients with borderline results for tTG antibodies - Sensitivity for celiac disease less than IgA anti-transglutaminase antibody test IgG deamidated gliadin peptide antibodies - Useful in patients with IgA deficiency and in young children - Not as sensitive or specific as tTG IgA antibodies HLA-DQ2 or HLA-DQ8 - High negative predictive value for celiac disease - Test is complex and expensive Small bowel biopsy - Reliable test, considered gold standard - Reflects response to treatment - Requires endoscopy and biopsy - Very expensive #Celiac #Disease #Testing #Laboratory #Tests #Diagnosis #Workup #Table
