Study On The Role Of Fas Protein And Soluble Fas In The Pathogenesis In Thyroid Associated Ophthalmopathy

Objective:Thyroid associated ophthalmopathy(TAO) is the most popular orbital disease, although the exact pathogenesis unknown, which has been looked as an organ specificity autoimmune disease by most researchers. The pathologic damage of extraocular muscles has been detected, that may be related with the infiltrated lymphocytes. The abnormality of immune adjustment is an essential factor in autoimmune disease including TAO, in which active immune status is reflected by the tendency of reoccurring and postponing.Apoptosis, also named programmed cell death, is regulated on gene level, and plays an important role in keeping the stable immune status. Apoptosis is involved in autoimmune disease in two aspects: ? cytotoxic T lymphocytes attack the target cell through apoptosis pathway signed by Fas protein. ?Instead of being decreased through apoptosis pathway , the activated lymphocytes gather in the body and upregulate immune status, so leading to autoimmune disease. Fas protein is expressed on the surface of target cell, and act as a key transferring apoptosis signal.Soluble Fas can protect lymphocytes from apoptosis in serum, therefore reflecting the immune activity to some extent.The relation is unknown between apoptosis and TAO due to deficiency of enough research. The aim of our research is to convince that apoptosis is involved in TAO, which may provide some new ideals for disease diagnosis and treatment.Methods:1.Using HE staining to detect the pathologic changes of the extraocular muscles,then using immunohistochemical technology, detecting the expression of Fas and Bcl-2 on the surface of extraocular muscle fibres.2.Measuring Serum sFas levels by ELISA in simple TAO, TAO accompanied by GD, simple GD and controls, then looking for the relation between sFas level and disease activity.Results:1. By detecting 8 pathologic slices of extraocular muscles in TAO, we founded the changes mainly appeared among the muscle fibres, including lymphocytes infiltration,GAG deposition and fatty cell hyperplasia. Additionally, we also founded some pathologic changes of muscle fibre themselves, but the pathogenesis isnot clear.2.Using immunohistochemical technology, we founded the statistic difference of Fas expression on the surface of extraocular muscle fibres between TAO group and control group(p<0. 01),but no statistic difference was founded of Bcl-2.3.Serum sFas levels in several groups were measured by ELISA. we founded sFas level in TAO accompanied by GD group (9.83 + 1.38 ng/ml) was higher than those in simple TA0(8.75 + 1.58 ng/ml) or simple GD(8. 28 + 1. 55 ng/ml) groups, and sFas levels in above three groups were higher than those in control group(5. 44+1. 00 ng/ml) (p<0. 01). Futher, sFas level in active TAO group(9. 63 + 1. 47 ng/ml) was higher than those...