Variability in Celiac Serology Testing by Provider Type: A Single-Center Experience

To evaluate the ordering practices of celiac disease (CD) serologies by providers at a tertiary, academic, Children's Hospital and compare them to guidelines and best practices.

We analyzed celiac serologies ordered in 2018 by provider type (pediatric gastrointestinal (GI) specialists, primary care providers (PCPs), and nonpediatric GI specialists), and identified causes for variability and nonadherence.

The antitissue transglutaminase antibody (tTG) IgA was ordered (n = 2504) most frequently by gastroenterologists (43%), endocrinologists (22%), and other (35%). Total IgA was ordered with tTG IgA for screening purposes in 81% of overall cases, but endocrinologists ordered it only 49% of the time. The tTG IgG was ordered infrequently (1.9%) compared with tTG IgA. Antideaminated gliadin peptide (DGP) IgA/IgG levels were also infrequently ordered (5.4%) compared with tTG IgA. The antiendomysial antibody was ordered sparingly (0.9%) compared with tTG IgA, but appropriately by providers with expertise in CD, similar to ordering for celiac genetics (0.8%). Of the celiac genetic tests, 15% were ordered in error. The positivity rate of the tTG IgA ordered by PCPs was 4.4%.

The tTG IgA was appropriately ordered by all types of providers. Endocrinologists inconsistently ordered total IgA levels with screening labs. DGP IgA/IgG tests were not commonly ordered but were inappropriately ordered by one provider. The low number of ordered antiendomysial antibody and celiac genetic tests suggests under-utilization of the nonbiopsy approach. The positive yield of tTG IgA ordered by PCPs was higher compared with previous studies.