Antiphospholipid antibodies in patients with Graves' orbitopathy: preliminary data

Abstract

Purpose: Graves' orbitopathy (GO) is an inflammatory autoimmune disorder of the orbit and while the antiphospholipid antibodies (aPL) Abs were associated with the markers of inflammation in the antiphospholipid syndrome (APS), there is no literature that investigate the presence of aPL Abs in GO. We analyzed the prevalence of aPL Abs and the differences between aPL (+) and aPL (-) subgroups of GO patients.

Methods: Study included consecutive patients with GO (66 with Graves' (GD), 10 with Hashimoto (HD), and 8 were euthyroid). Anticardiolipin (aCL) and anti-beta 2glycoprotein I (aβ2gpI) Abs were measured by ELISA.

Results: aPL Abs were present in 9/84 (10.71%) patients. The IgM aβ2gpI Abs were present in 8/66 and in 1/10 patients with GD and HD. The IgG aCL Abs were present in one GD patient, and IgM aCL were present in 3/66 GD and in 1/10 patients with HD. In GD group, anti-Tg Abs were in positive correlation with aβ2gpI IgG (p = 0.000) and with anti-TPO Abs (p = 0.016). In HD group, anti-Tg Abs were in positive correlation with IgM aCL (p = 0.042), while anti-TPO Abs were in positive correlation with aβ2gpI IgM (p = 0.014).

Conclusion: This study is the first report of the aPL Abs presence in GO patients. The anti-thyroid Abs were linked to aPL suggesting that their presence is not the sole consequence of hyperstimulation of autoreactive B-lymphocytes. Larger studies are necessary to confirm potential cause-effect relations.

Keywords: Antiphospholipid antibodies; Apolipoproteins; Autoimmune thyroid diseases; Graves’ orbitopathy; Interleukine 6.