Endocrine Abstracts

Introduction: Patients with autoimmune thyroid disease (AITD) exhibit aberrant immune-regulatory mechanisms. Galectins (Gal) are a family of glycan-binding proteins, which have been involved in immune regulation. However, the association of Gal with AITD remains unknown. In this study, we evaluated serum Gal-1 and Gal-9 in patients with AITD.

Methods: Peripheral blood samples from 31 patients with Graves’ disease (GD) (14 with untreated hyperthyroidism, nine euthyroid with treatment, eight with iatrogenic hypothyroidism), 26 Hashimoto’s thyroiditis (HT) (20 hypothyroid, six euthyroid with treatment), 12 non-GD hyperthyroid patients (NG) and 24 healthy controls were studied. Serum levels of thyroid hormones, thyroid antibodies (Ab), Gal-1 and Gal-9 were measured on the same day (FT4 by RIA; TSH, Tg-Ab, TPO-Ab and TSHR-Ab by immunoradiometric assays; Gal-1 and Gal-9 by ELISA). Patients were grouped according to clinical diagnosis and thyroidal status.

Results: Serum Gal-1 (ng/ml) and Gal-9 (pg/ml) were significantly increased in GD (3.756 and 8.582 respectively), HT (3.085, 9.188) and NG (2.822, 8.983), in comparison to controls (1.508, 7.323), P<0.05. No significant differences in Gal levels were found between the first three groups. Patients with hyperthyroidism (both GD and NG) had higher Gal-9 levels than euthyroid AITD patients, although there were no differences in Gal-1. In fact, in GD, we observed a direct correlation between Gal-9 and FT4 (r=0.517, P=0.006), and an inverse correlation between Gal-9 and TSH (r=-0.478, P=0.007). We did not find an association between Gal-9 and Ab levels in either group of AITD, although an association between Gal-1 and TPO-Ab levels was found in HT (r=-0.512, P=0.038). Antithyroid treatment reduced Gal-1 levels in patients with GD.

Conclusions: Galectins may be involved in the severity and pathogenesis of AITD, and could potentially be used as a diagnostic and therapeutic marker.

Disclosure: Grants form Fundación SEEN Award for Young Endocrinologists, FIS 13/1414 and PIE 13/41.