To evaluate the diagnostic performance of celiac serologic tests in asymptomatic patients with type 1 diabetes (T1D).
Patients with T1D asymptomatic for celiac disease were prospectively screened with immunoglobulin A anti-tissue transglutaminase. Test characteristics were calculated and optimal cutoffs for a positive screen determined.
Two thousand three hundred fifty-three patients were screened and 101 proceeded to biopsy. The positive predictive value of immunoglobulin A anti-tissue transglutaminase at the assay referenced upper limit of normal (30CU) was 85.9%, and the sensitivity and specificity were 100% and 38%, respectively.
Thresholds extrapolated from the general population for the diagnostic evaluation of celiac disease are not suitable for use in asymptomatic T1D patients. Population-specific screening cutoffs are required.