Protein expression of VEGF, IGF-1 and FGF in retroocular connective tissues and clinical correlation in Graves' ophthalmopathy

Abstract

To investigate the immunohistochemical expression (IGF-1, EGFr, EGF, c-erbB-2/HER-2/neu, PDGF-A, PDGF-B, FGF and VEGF) in patients with Graves' ophthalmopathy. Twenty-four samples (Graves' ophthalmopathy patients) underwent lateral rectus muscle and surrounding fibrous and adipose tissue biopsy. The control group was obtained by strabismus surgery. Correlation between clinical-ophthalmologic, endocrinological, ultrasonographic findings, and immunohistochemical expression was performed. IGF-1: There were 7 positive cases (29.2%). There was a direct relation with higher CAS (clinical activity score) in all of them and if only CAS equal or higher than 5 was considered, this was 54.5%. FGF: There was expression in 5 cases (20.8%) with a direct relation in all those with higher CAS (>5) (45.4%). VEGF: There were two positive cases (8.3%) for VEGF in endothelial cells, in these cases the patients also presented CAS higher than 5. There was no expressions of all growth factors in the control group. All patients, except one, with positive expression of FGF, IGF-1 and VEGF showed CAS greater than 5, suggesting in this way an important role of these growth factors in the pathogenesis and severity of Graves' ophthalmopathy. However, statistical analysis revealed only significant association between IGF-1 and male sex (P=0.034). Low ultrasound reflectivity and endocrine status may not correlate directly with disease activity or with immunoexpression of growth factors and c-erbB-2/HER-2/neu.