Coincidence of high antiislet and antithyroid autoantibody titles in first-degree relatives of patients with type 1 diabetes.
An association between thyroid and islet autoantibodies has been reported for patients with type 1 diabetes and their first-degree relatives. However no general agreement on this association has been reached since several studies reported controversial data. In the present study, sera from 429 healthy first-degree relatives of type 1 diabetic patients have been examined for the presence of thyroid and islet autoantibodies. Autoantibodies against glutamate decarboxylase (GAD65Ab) and tyrosine-phosphatase IA-2 (IA-2/ICA512Ab) have been detected by radioimmunoassay techniques with in vitro translated recombinant human 35S-autoantigens. The presence of autoantibodies against thyroid peroxidase (TPOAb) and thyroglobulin (TgAb) has been estimated by commercial radioimmunoassay kits. An increased frequency of TgAb was found in subjects who were positive for GAD65Ab (p=0.0257). However, no significant association between TPOAb and GAD65Ab or IA-2Ab or between TgAb and IA-2Ab could be established. These data indicate an increased rate of coincidence between TgAb and GAD65Ab in healthy first-degree relatives of type 1 diabetic patients. Accordingly a common genetic background leading to the appearance of both TgAb and GAD65Ab may be suggested.
Sougioultzoglou
F
F
Diabetes Center, Hippokratio Hospital, Medical School, Aristotle University, Thessaloniki, Greece.
Falorni
A
A
Kassi
G
G
Brozzetti
A
A
Karamitsos
D
D
Koliakos
G G
GG
D000293:Adolescent; D000328:Adult; D001323:Autoantibodies / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics* / Q000276:immunology*; D005260:Female; D005968:Glutamate Decarboxylase / Q000276:immunology; D006801:Humans; D007515:Islets of Langerhans / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009679:Nuclear Family; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1; D017027:Protein Tyrosine Phosphatases / Q000276:immunology; D013961:Thyroid Gland / Q000276:immunology*
D001323:Autoantibodies; C024211:islet cell antibody; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1; D017027:Protein Tyrosine Phosphatases; D005968:Glutamate Decarboxylase