Comparison of atrophic and goitrous auto-immune thyroiditis in children: Clinical, laboratory and TSH-receptor antibody studies

Abstract

We studied the clinical features, laboratory and thyroid functions and thyrotropin (TSH)-receptor and thyroid-stimulation antibodies in 21 patients with atrophic auto-immune thyroiditis (AAT) and 48 patients with goitrous auto-immune thyroiditis (GAT) of childhood onset. The clinical features of patient with AAT were cessation of growth and obesity, while asymptomatic enlargement of the thyroid gland was the sole symptom in most patients with GAT. Although the ages at diagnosis were comparable in both groups, the estimated ages at onset were much lower in patients with AAT than in those with GAT. Patients with AAT exhibited more severe hypothyroidism when evaluated by serum thyroxine (T4), tri-iodothyronine (T3), TSH, cholesterol levels and basal metabolic rates. The 24 h 123I-thyroidal uptake was significantly lower in patients with AAT than in those with GAT. None of the 19 patients with AAT possessed TSH-binding inhibitor immunoglobulins (TBII). On the other hand, 3 of the 32 GAT patients tested, possessed weak to potent TBII activities. Three TBII-positive patients with GAT also possessed thyroid-stimulation blocking antibodies. These findings suggest that: 1. Pathogenesis of AAT in children whose onset of hypothyroidism was before puberty is not due to TSH-receptor blocking antibodies, which are often found in patients with AAT of postpubertal onset. 2. AAT in children is considered not to be due to the later stage of GAT. 3. Some patients with GAT possessed TSH-receptor blocking antibodies. The aetiology and pathogenesis of AAT in children have yet to be elucidated.

The frequency of Hashimoto thyroiditis in children and the relationship between urinary iodine level and Hashimoto thyroiditis

“…In studies covering childhood and adolescence age groups, there are different data about the girl/boy ratio ranging from 2:1 to 9.7:1 (4,5,19) . This ratio was found to be 6.6 in the study of (20). Furthermore, in our country, the girl/boy ratio in HT was found to be 5:1 in the study of Yasin et al, 6.3:1 in the study of Huseyin et al, and 8.7:1 in the study of Ediz et al (21 -23) .…”

Assays for Thyroid-stimulating Antibodies and Thyrotropin-binding Inhibitory Immunoglobulins in Children with Graves' Disease

“…It is reported that children with atrophic autoimmune thyroiditis (AAT) did not possess TSBAb, which are often found in adult patients with AAT [23]. Similarly, it is possible that children with Graves' disease seldom possess TSBAb, and so the correlations between TSAb and TBII might be strongly positive.…”

A 5-year-old boy with atrophic autoimmune thyroiditis caused by thyroid-stimulation blocking antibodies

“…Transient hypothyroidism in some pediatric patients with CLT has also been reported. In these patient TSBab gradually decreases over a couple of years (12,13) . However, in the present case, TRAb remained extremely elevated over 24 months (data not shown).…”

“…However, most studies on TSBab in AAT have been limited to cases of post-pubertal onset. Matsuura et al found no TBII and TSBab activities in patients of AAT with prepubertal onset (19 cases) or chronic thyroiditis (32 cases) (12) . Only two prepubertal cases testing positive for TBII have been reported (7,10) .…”