ANSWER: A
Critique
While small bowel biopsies are the gold standard test for the exclusion of celiac disease, HLA typing for DQ2 and DQ8 (A) is very useful as an exclusionary test for celiac disease, as the diagnosis is quite unlikely in their absence. DQ2 and DQ8 haplotyping also are useful when small intestinal biopsies are equivocal. Antigliadin antibodies (B & C) do not have particularly high negative predictive values, and have little value here. Also, gluten challenge testing (E) would be of limited utility in excluding the presence of celiac disease.
Reference
1. Liu E., Rewers M., Eisenbarth G.S. Genetic testing: who should do the testing and what is the role of genetic testing in the setting of celiac disease? Gastroenterology 2005;128(4 Suppl 1):S33-7.
