Autoantibodies to Glutamic Acid Decarboxylase in Patients with IDDM and Autoimmune Thyroid Disease

The presence of antiglutamic acid decarboxylase antibody (GADA) is required for the diagnosis of slowly progressive type 1 diabetes (SPT1D). We examined the factors influencing GADA determination by radioimmunoassay (GADA-RIA) and by enzyme-linked immunosorbent assay (GADA-ELISA). Sixty patients with SPT1D and 154 patients with type 2 diabetes were examined by both GADA-RIA and GADA-ELISA and for the presence of autoimmune thyroid disease (AITD). We compared the clinical characteristics of these patients based on the positivity or negativity of GADA-RIA and GADA-ELISA, and the existence or nonexistence of AITD. Thirty of 60 (50.0%) GADA-RIA-positive patients were GADA-ELISA negative, whereas none of the 154 GADA-RIA-negative patients were GADA-ELISA positive. Concomitant AITD was significantly less in patients with GADA-RIA and without GADA-ELISA and was significantly more in patients with GADA-RIA and GADA-ELISA. In GADA-RIA-positive patients, there was no significant difference in the GADA-RIA titer among the GADA-ELISA-negative patients with and without AITD, and the GADA-ELISA-positive patients without AITD; whereas the frequency of insulin deficiency was significantly higher in the patients with AITD and/or GADA-ELISA than in those without AITD and GADA-ELISA. Examination of GADA-ELISA and AITD in GADA-RIA-positive patients might be useful in predicting insulin deficiency in these patients.

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

10.21203/rs.3.rs-1207932/v1 ◽

2022 ◽

Author(s):

Natasa Rojnic Putarek ◽

Nevena Krnic ◽

Jadranka Knezevic-Cuca ◽

Vesna Kusec ◽

Maja Baretic ◽

...

Keyword(s):

Thyroid Disease ◽

Autoimmune Thyroid Disease ◽

Tyrosine Phosphatase ◽

Family Members ◽

Islet Autoantibodies ◽

Islet Autoimmunity ◽

Acid Decarboxylase ◽

Autoimmune Thyroid ◽

Number Of Patients ◽

Normal Glucose

Abstract 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). Higher prevalence of islet autoantibodies was found in females with AITD (p=0.011) but not in males (p=0.16) as well as in AT (p=0.013) but not 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) compared to AITD patients with single islet autoantibodies but normal glucose metabolism. T1D was found in 3.7% of AITD patients compared to 0.2% in 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 autoantibodies 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 last observation must be examined in a larger number of patients.

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Besondere Manifestationsformen der Autoimmunthyreopathie

Praxis ◽

10.1024/0369-8394.91.27.1151 ◽

2002 ◽

Vol 91 (27) ◽

pp. 1151-1160

Author(s):

Fajfr ◽

Müller

Keyword(s):

Thyroid Disease ◽

Autoimmune Thyroid Disease ◽

Chromosome 6 ◽

Autoimmune Thyroid

Les maladies thyroïdiennes auto-immunes ou immunes (autoimmune thyroid disease, AITD) sont relativement fréquentes. Le terme de AITD comprend les thyréodites euthyroidiennes ou hypothyroïdiennes de Hashimoto avec ou sans goitre, les hyperthyroïdies classiques de Basedow et leurs variantes nettement plus rares euthyroïdiennes ou hypothyroïdiennes. Aucune des nombreuses classifications des AITD n'a pu s'imposer sur le plan international. La pathogénèse de toutes les formes d'AITD comprend une perturbation de la tolérance immune chez les individus prédisposés génétiquement (séquence HLA-DQAI*0501 sur le bras court du chromosome 6) qui provoque un processus auto-immun contre la glande thyroïdienne. Ces processus sont soit destructeurs ou inhibiteurs, soit stimulateurs, ce qui permet d'expliquer les formes très différentes de AITD. Dans de cas rares, ces processus peuvent se contrebalancer («balance hypotheseis»). Les anticorps anti-récepteurs TPO et TSH (TRAK) ont une place particulière dans le diagnostic des AITD. Les dosages de routine utilisent pour la mesure des TRAK des récepteurs qui ne peuvent pas différencier entre les anticorps stimulants ou bloquants contre les récepteurs TSH. C'est, entre autre pour ces raisons, que les résultats d'anticorps positifs ne sont utilisables qu'en connaissance de la clinique et / ou des paramètres de la fonction thyroïdienne. Ce travail présente quatre patients avec des formes plus complexes d'AITD et résume les connaissances actuelles.

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