Endocrine Abstracts

Background: The association between autoimmune thyroid disease (AITD) and other autoimmune diseases is well-known. The prevalence of concurrent autoimmune gastritis and celiac disease in AITD has been estimated at approximately 20–25% and 2–5% respectively. Although both conditions have significant morbidity including malignancy and may necessitate dietary modifications and endoscopic evaluation, no recommendation exists to screen AITD patients for these autoimmune disorders.

Objective: To assess the prevalence of anti-parietal cell antibodies (APCA) and celiac antibodies (tissue-transglutaminase antibodies, tTg) in ambulatory patients with autoimmune thyroid disease.

Methods: Due to the high prevalence of celiac disease and autoimmune gastritis in AITD patients presented in prior studies, it is standard practice in our clinic to recommend serological screening to AITD patients for these conditions. A retrospective study was performed including patients with AITD who presented to our clinic between 01/01/2016 and 31/12/2018. AITD was defined by positive thyroglobulin or thyroid-peroxidase antibodies. AITD patient charts were searched for thyroid disease presentation (hypothyroid, hyperthyroid, mixed or euthyroid) and for tTg and APCA test results. We present a preliminary report of our data.

Results: Our preliminary cohort included 118 AITD patients, of whom 100 (84.7%) were female and 18 (15.3%) were male. Sixty-six presented clinically with Hashimoto thyroiditis, 40 with Graves’ disease, three with mixed Hashimoto-Thyrotoxicosis, and nine were clinically euthyroid. Ninety-three patients had undergone assessment for celiac antibodies and 53 for APCA. Anti-parietal cell antibodies were positive in 10 of 53 patients tested (18.9%), 6 of whom were female; 7/10 had vitamin B12 deficiency and two were diagnosed with type 1 gastric neuroendocrine tumor. Two of 93 patients who performed celiac serology (2.2%) had a positive tTg; a third patient had known celiac disease. All three patients were female; one had both APCA and celiac antibodies.

Conclusion: The frequency of tTg and APCA in our preliminary study is concordant with results of similar prior studies and alludes to a higher prevalence of celiac disease and autoimmune gastritis in AITD. However, our study may have overestimated disease prevalence, as not all patients performed serological screening, and some may have been evaluated due to suggestive symptoms rather than as screening. The increased prevalence of these conditions reported in several studies, and their important associated morbidities and treatment implications advocates for a role for screening in AITD patients.