Prevalence of growth hormone deficiency in Hashimoto's thyroiditis

Primary Hypothyroidism with Pituitary Hyperplasia in an Omani Girl

Pituitary hyperplasia secondary to primary hypothyroidism (PHPH) is uncommon in children and is reversible with thyroxine therapy. We report an Omani girl who presented at the age of 13 years and 6 months with profound primary hypothyroidism due to Hashimoto's thyroiditis and secondary pituitary hyperplasia and hyperprolactinemia. Pituitary magnetic resonance imaging confirmed the presence of pituitary hyperplasia which regressed during follow-up after the administration of thyroxine therapy. The diagnosis of PHPH is very important in both children and adults in order to avoid unnecessary brain surgery or medical treatment for a presumed pituitary mass or adenoma. To our knowledge, this patient represents the first case of an Omani child presenting with PHPH.

Tumor-associated and disease-associated autoantibody repertoires in healthy colostrum and maternal and newborn cord sera

In this work, we studied autoantibody repertoires and Ig isotypes in 71 mothers and their 104 healthy newborns (including twins and triplets delivered term or premature). Newborns receive maternal IgG Abs via the placenta before birth, but developing infants must produce their own IgM and IgA Abs. We used an Ag microarray analysis to detect binding to a selection of 295 self-Ags, compared with 27 standard foreign Ags. The magnitude of binding to specific self-Ags was found to be not less than that to the foreign Ags. As expected, each newborn shared with its mother a similar IgG repertoire-manifest as early as the 24th week of gestation. IgM and IgA autoantibody repertoires in cord sera were highly correlated among the newborns and differed from their mothers' repertoires; the latter differed in sera and milk. The autoantibodies bound to self-Ags known to be associated with tumors and to autoimmune diseases. Thus, autoantibody repertoires in healthy humans--the immunological homunculus--arise congenitally, differ in maternal milk and sera, and mark the potential of the immune system to attack tumors, beneficially, or healthy tissues, harmfully; regulation of the tissue site, the dynamics, and the response phenotype of homuncular autoimmunity very likely affects health.

Low prevalence of growth hormone deficiency in Turkish patients with Hashimoto's thyroiditis

BACKGROUND

Hashimoto's Thyroiditis (HT) is frequently isolated, but may also be associated with other autoimmune disorders. Autoimmune hypophysitis can result in growth hormone deficiency (GHD). Various prevalences of GHD have been reported in HT in several different ethnic populations.

AIM

The aim of this study was assessing the prevalence of GHD in Turkish population with HT.

MATERIALS AND METHODS

Two hundred twenty-seven (208 females and 19 males, mean age 40.1 ± 10.8 years, range 18-64 years) patients with euthyroid HT were included.

RESULTS

All patients were euthyroid with or without T4 treatment (median TSH 2.2 mIU/L, range 0.2-4.2 mIU/L; median FT4 15.6 pmol/L, range 12-22 pmol/L; and median FT3 4.5 pmol/L, range 3.0-6.2 pmol/L), and median TPO-Ab was 817 IU/mL (range 63 to >3,000). One hundred and thirty-six of them were using medications including L-thyroxine (59.9 %). Insulin-like growth factor-I (IGF-I) levels of 210 patients (92.5 %) were normal. Glucagon stimulation testing in 17 subjects revealed GHD (peak <3 mcg/L) in two subjects. We then performed insulin tolerance test (ITT) to both of them as the gold standard confirmatory test. One patient had no GH response to ITT, either. Our data reveal the prevalence of GHD (based on low IGF-I and ITT result) in this particular group of Turkish HT patients as 0.4 %.

CONCLUSION

We conclude that the isolated GHD is rarely observed in HT in our population. The prevalence of GHD is 0.4 % in this particular group of Turkish HT patients suggesting that routine investigation of GHD is not mandatory.

Diseases associated with thyroid autoimmunity: explanations for the expanding spectrum

Anyone who has been in an endocrine clinic will appreciate that associations exist between autoimmune thyroid disease (AITD) and other autoimmune disorders. However, the full extent of these associations is still not fully appreciated, and new associations are being uncovered which may shed new light on the pathogenic basis for these connections, and the underlying reasons for them are only now becoming understood. This review is based on the British Thyroid Association Pitt-Rivers Lecture 2010. The first section provides an update on studies which have detailed the strength of various autoimmune disease associations, the second section discusses the environmental and genetic factors which underlie these associations and the final section describes some recently identified, unexpected AITD associations. Unravelling these associations further will illuminate the pathogenesis of autoimmune diseases and offers the prospect of new therapeutic approaches.