Endocrine Autoimmunity and Function in Adolescent Coeliac Patients: Importance of the Diet.

This is the authors' abstract. We don't add key points for this paper.

It is well known that coeliac patients may develop, with high incidence, autoantibodies against endocrine glands. In order to evaluate if the endocrine glands autoimmunity and function may be related to dietary habits we have investigated endocrine autoimmunitary markers and function in fourty-two patients (28 females), aged between 11 and 20 yrs, 23 on a gluten-free diet (Group A), 19 on a gluten-containing diet (Group B). Adrenal glands, endocrine pancreas and thyroid autoimmunity were investigated, evaluating antibodies against -21 hydroxylase (-21OH), -peroxidase (-TPO), -Thyreoglobulin (-TG), glutamic acid decarboxilase (-GAD 65), islet cell antibody (-ICA), - islet cell antibody 512 abc (-ICA512 abc), insulin autoantibody (-IAAb). TSH, FT3, FT4, T3, T4 were assayed to evaluate thyroid function. 17-OH progesterone and cortisol were analysed basally and 60' after i.v. ACTH stimulation to evaluate adrenal function. Fasting glycemia level (expressed in mmol/l) was used to evaluate the endocrine pancreas function. RESULTS As far as the autoantibodies are concerned, none of the patients were positive for -21-OH Ab, 5/42 were positive for -TPO Ab, 5/42 were positive for TG Ab, 4 of whom were the same patients showing -TPO Ab positivity. Therefore in 6/42 at least one antibody directed against thyroid tissue was positive. When we have investigated pancreas autoimmunity, we observed that 7/42 were ICA positive, 1/42 showed positivity for GAD, 1/42 for IAAb and none for ICA-512 abc. The patient positive for ICA, GAD and IAAb was diabetic. Among these patients only one showed one of the thyroid autoantibodies positive. Therefore in 12/42 at least one antibody against an endocrine tissue was positive. Adrenal function, at least for the parameters evaluated, was normal in all subjects. As far as thyroid function is concerned, one patient showed clinical hypothyroidism (TSH>6), and two patients showed preclinical hypothyroidism. All but one patients studied showed fasting glycemia levels within the normal range. Interestingly, at least one antibody was positive in 9 out of 19 Group B patients (47.4%) but only in 3 out of 23 Group A patients (13%) with a significant difference (p<0.05) between the 2 Groups. CONCLUSIONS The study demonstrated: 1.a high percentage of autoantibodies directed against thyroid and endocrine pancreas in coeliac adolescents, particularly in those on a gluten-containing diet; 2. an endocrine function only slightly affected, suggesting the presence of a primitive autoimmune disorder that may induce, over the time, the development of an autoimmune organ specific disease: a follow up study will confirm this hypotesis; 3. that the gluten-free diet seems to decrease the risk of the development of endocrine autoimmunity.