Endocrine Abstracts

Aim: It is well known that T1D is associated with other autoimmune diseases. The aim of this study was to compare the prevalence of various auto-antibodies in first-degree relatives of patients with T1D and healthy individuals with negative family history of diabetes.

Material and methods: The group studied consisted of 90 relatives and 60 healthy individuals. Serum concentrations of antibodies to anti-21-hydroxylase (21-OH-Abs), anti-gastric parietal cell antibodies (GPC-Abs), anti-thyroglobulin antibodies (TG-Abs), anti-thyroid peroxidase antibodies (TPO-Abs) and anti-TSH receptor antibodies (TSHR-Abs) were measured by commercial radioimmunoassay.

Results: Positive antibodies against pancreatic islet antigens were found in 34.4% of the relatives (IAA in 23.3%, GADA in 16.7% and IA-2A in 2.2%) and in none of the controls. Other antibodies (mainly TPO-Abs, TSHR-Abs and GPC-Abs) were detected in 40% of all relatives and in 93.5% of these with positive anti-islet antibodies. Median levels of 21-OH-Abs, GPC-Abs, TPO-Abs and TSHR-Abs were significantly higher in the relatives, in particular these with positive anti-islet antibodies, as compared with the group of relatives with no anti-islet antibodies and the controls. A positive correlation between IAA and TPO-Abs levels was noted in the whole group of relatives, as well as in a subgroup with anti-islet antibodies (r=0.549, P<0.05 and r=0.567, P<0.05 respectively).

Conclusions: Our results demonstrated for the first time significantly higher prevalence of anti-thyroid antibodies and anti-gastric parietal cell antibodies in the first degree relatives of T1D patients, in particular in these with positive anti-islet antibodies. The finding suggest that these subjects may be at higher risk of developing not only type 1 diabetes, but also other autoimmune disorders and should be routinely screen especially for autoimmune thyroid disease and auto-immune gastritis.