Matrix metalloproteinases-1, -13 and their tissue inhibitor-1 in endocrine ophthalmopathy

Abstract

The study included 65 people (130 eyes) at the age of 43 (35-50) years. Three groups of subjects were formed: 32 patients with a moderate GO severity (clinical group), 18 patients with autoimmune thyroid pathology without GO (comparison group), and 15 healthy persons (control). The diagnosis was based on clinical, laboratory, and instrumental data. A comprehensive ophthalmologic examination and blood sampling for determination of MMP-1, -13, TIMP-1, sulfated glycosaminoglycans (sGAG) and antibodies to thyroid-stimulating hormone receptor (TSHRAbs) were conducted. The data were statistically processed using the program Statistica 10.0. An elevated level of MMP-13, observed in all GO patients (p<0.05). For the active phase of GOP, the comparison with the control group showed a 3.5-fold increase in MMP-13 (p<0.001) and 1.17-fold rise in TIMP-1 (p>0.05). Pulse glucocorticoid therapy reduced MMP-13 by 48.6% (p<0.001), TIMP-1 by 2.7% (p<0.001), and TSHRAbs - by 93% (p<0.001) compared with active GO, but these indicators were higher than the reference limits of control (p>0.05). In inactive GO, despite increased MMP-13, TIMP-1 decreased to the reference values (p=0.533). There were no significant differences in MMP-1 in groups of subjects (p=0.865). We have found imbalance between MMP-13 and TIMP-1 production in different activity phases of GO. Active GO is characterized by an increase in serum MMP-13 and TIMP-1. Dysregulation of intercellular matrix remodeling, possibly, underlies the development of extraocular muscles and retrobulbar tissue fibrosis in GO.