ESPE Abstracts

Background: Type 1 Diabetes Mellitus (T1DM) often coexists with other autoimmune diseases, either individually or as a part of polyendocrine syndrome (APS I-III). It is frequently associated with autoimmune thyroid, celiac, gastric and Addison’s disease. In the families with T1DM patients frequently coexist different autoimmune diseases (familial autoimmunity).

Objective and hypotheses: Evaluating the frequency of associated and familial autoimmunity in T1DM patients and predisposing factors.

Method: We studied 93 T1DM children and adolescents (boys/girls: 44/49) with a mean±S.D. age of 12.5±4.7 years (range: 1.5–18 years), disease duration 4.7±4.0 years and age at T1DM diagnosis 8.0±3.5 years. The following autoantibodies were recorded: a) celiac disease: against tissue transglutaminase (anti-tTG-IgA) and endomysium (anti-EMA-IgA and IgG), b) Hashimoto thyroiditis (HT): against thyroid peroxidase (anti-TPO) and thyroglobulin (anti-Tg), c) autoimmune gastritis: against gastric parietal cells (APCA), d) Addison’s disease: against adrenal cortex (ACA).

Results: Double autoimmunity was found in 25/93 patients (26.9%) and triple in 6/93 (6.5%). HT was diagnosed in 20 (21.5%) patients, celiac disease in 11 (11.8%), autoimmune gastritis in 5 (5.4%) and psoriasis in one patient (1.0%). Familial autoimmunity was present in the families of 46% patients: HT in 32 (34.4%), T1DM in 17 (18.3%), gastritis in 2 (2.1%), multiple sclerosis 2 (2.1%), while celiac disease, Myasthenia Gravis and psoriasis occurred in 1 relative (1.1%) each disease. The appearance of associated autoimmunity was not correlated with gender (boys 12/44 (27.3%) vs girls 21/49 (42.8%), P=0.088) and the age at T1DM diagnosis (<5 years: 10 (45.5%) vs >/5 years: 17 (30.3%), P=0.290).

Conclusion: Associated autoimmunity is quite common (33.3%) among T1DM children and adolescents, with Hashimoto’s thyroiditis being the most frequent, followed by celiac disease. Familial autoimmunity was observed in 46% of patients, with HT and T1DM being the most frequent. It is therefore necessary the regularly assess children with T1DM for associated autoimmunity and look for familial autoimmunity.