J Clin Res Pediatr Endocrinol. Ahead of Print: JCRPE-31932 | DOI: 10.4274/jcrpe.galenos.2023.2023-10-18

Relative Frequency of Islet Autoimmunity in Children and Adolescents with Autoimmune Thyroid Disease

Natasa Rojnic Putarek¹, Nevena Krnic², Jadranka Knezevic-cuca³, Vesna Kusec³, Maja Baretic⁴, Miroslav Dumic^5
1Department of Pediatric Endocrinology and Diabetes, University Hospital Centre Zagreb, School of Medicine, Kispaticeva 12, 10 000 Zagreb
²Vuk Vrhovac Clinic for Diabetes, Endocrinology and Metabolic Diseases, University Hospital Merkur, School of Medicine, University of Zagreb, Zajceva ul. 19, 10000 Zagreb, Croatia
³Clinical Institute of Laboratory Diagnosis, University Hospital Centre Zagreb, Kispaticeva 12, 10000 Zagreb
⁴Department of Endocrinology, University Hospital Centre Zagreb, Croatia School of Medicine, Kispaticeva 12,10 000 Zagreb
⁵Department of Pediatrics, University Hospital Center Zagreb, School of Medicine, Kispaticeva 12,10 000 Zagreb

INTRODUCTION: The present study aims to investigate islet autoimmunity and susceptibility to type 1 diabetes (T1D) in children/adolescents
with autoimmune thyroid disease (AITD, and family members of AITD patients with islet autoimmunity. Islet-cell
cytoplasmic, glutamic-acid decarboxylase, and tyrosine-phosphatase autoantibodies were measured in 161 AITD patients
[(127 with autoimmune thyroiditis (AT); 34 with Graves’ disease (GD)], 20 family members of AITD patients with islet
autoimmunity, and 155 age-matched controls. Islet autoimmunity was found in 10.6% of AITD patients, significantly more
frequent than in controls (1.9%; p=0.002). A higher prevalence of islet autoantibodies was found in females with AITD
(p=0.011) but not in males (p=0.16) and AT (p=0.013) but not in GD patients (p=0.19), compared to corresponding controls.
Two or three islet autoantibodies were found concurrently in six AITD patients with islet autoimmunity. They all developed
T1D and had significantly higher islet autoantibodies titers (p=0.01) than AITD patients with single islet autoantibodies but
normal glucose metabolism. T1D was found in 3.7% of AITD patients compared to 0.2% of the age-matched, general
Croatian population. Islet autoantibodies were found in 5/20 family members of AITD patients with islet autoimmunity,
among which two developed T1D. None of the controls was positive to more than one islet autoantibody or developed T1D.
Conclusion: Children/adolescents with AITD (particularly females and patients with AT) represent a risk group for islet
autoimmunity and T1D, as well as family members of AITD patients with positive islet autoantibodies, but the last
observation must be examined in a more significant number of patients.
METHODS:
RESULTS:
DISCUSSION AND CONCLUSION:

Keywords: Autoimmune thyroid disease, islet autoimmunity, screening, diabetes mellitus type 1, children

---