Expression and clinical significance of connective tissue growth factor (CTGF) in Graves' ophthalmopathy

To examine the expression of connective tissue growth factor (CTGF) in human cultured orbital fibroblasts from patients with Graves' ophthalmopathy (GO) and investigate whether a correlation exists between the presence of CTGF protein and clinical parameters of the disease.

The protein expression levels of CTGF were analysed by western blots in cultured orbital fibroblasts from 10 patients with GO and 7 age-matched normal controls. Associations between the protein expression of CTGF and the clinical factors of GO, including clinical demographics, thyroid function, clinical activity score (CAS) and ophthalmopathy index (OI), was evaluated.

The mean protein expression levels of CTGF in the GO orbital fibroblasts were significantly higher than those of normal controls (p<0.001). Based on further analysis, the protein expression levels of CTGF in the GO orbital fibroblasts had significant correlation with gender (p=0.029), serum levels of thyrotropin receptor antibodies (p=0.029), CAS (p=0.048) and OI (p=0.043). Especially, there was a significant correlation between protein expression levels of CTGF and lid oedema (p=0.037), proptosis (p=0.045) and corneal involvement (p=0.001).

Our findings revealed that the protein expression levels of CTGF in the GO orbital fibroblasts were significantly highly expressed than those of normal controls, and the elevated CTGF was associated with clinical characteristics and evolution, indicating CTGF may play a role in the pathogenesis and pathophysiology of GO.