Analysis of the Expression of Fas,FasL and Bcl-2 in the Pathogenesis of Autoimmune Thyroid Disorders

To investigate the expression of apoptosis-related protein(Fas,FasL,and Bcl-2)in the pathogenesis of autoimmune thyroid disorders (ATDs),immunohistochemical staining was performed on 20 Hashimoto's thyroiditis(HT),20 Graves'disease(GD),and 20 thyroid follicular adenoma(TFA,as control).All the cases expressed Fas,mainly on the cell surface and cytoplasm.FasL was found in 17 cases of the TFA.Bcl-2 was detected in 15 cases of HT,19 of GD and 17 of TFA.In TFA,a moderate Fas expression and a minimal or no FasL expression was detected on follicular cells.In HT,the follicles adjacent to infiltrating lymphocytes showed increased levels of Fas and FasL expression.A weaker staining of Fas and FasL was exhibited on infiltrating lymphocytes than on thyrocytes.In a comparison of GD with HT,thyrocytes and lymphocytes showed similar Fas staining,but for FasL the staining was rather weaker in HT.The expression of Bcl-2 was nearly identical in GD and TFA,but much weaker on the follicular cells in vicinity of lymphocytes and on the lymphocytes located in germinal centers of HT tissues.The expression of Fas,FasL,Bcl-2 in Hashimoto's thyroiditis and Graves' disease were almost same.FasL strong expression and Bcl-2 weak expression on the follicles in HT may induce apoptosis.These results provided evidence for expression of Fas,FasL and Bcl-2 in the pathogenesis of autoimmune thyroid disease.The lymphocytes seem not to be directly engaged in the process via their own FasL,but they may provide some cytokines that,in turn,upregulate Fas and/or FasL expression to induce apoptosis.Cellular & Molecular Immunology.2004;1(3):224-228.

The Expression and Distribution of S-100 Protein and CD83 in Thyroid Tissues of Autoimmune Thyroid Diseases

To investigate the expression and distribution of S-100 protein and CD83 in the thyroid tissues of autoimmune thyroid diseases(ATDs),and to study the role of the dendritic cells in the pathogenesis of ATDs, immunohistochemical staining was used on pathological tissues of 20 patients with Hashimoto's thyroiditis(HT) and 20 patients with Graves' disease(GD) to check the expression and distribution of S-100 protein and CD83. Compared with control group(20 cases of thyroid follicular adenoma,TFA),the higher expressions of S-100 in HT(139.38±5.92 vs 59.47±11.69) and GD(119.42±14.48 vs 59.47±11.69) were observed respectively(p< 0.001).The increased positive expressions of CD83 which is known as a marker of mature and activated DCs in HT(22.58±13.96 vs 5.19±8.08) and GD(29.92±14.43 vs 5.19±8.08) were also found respectively(p<0.001). Serum TPO antibody(TPO-Ab,67.3±11.6%) and Tg antibody(Tg-Ab,59.8±10.1%) in HT were higher than those in GD(28.4±5.7%,23.1±4.9%) and TFA(6.1±3.4%,7.2±4.6%)(p<0.01).Serum TR-Ab in GD(16.3 ±5.6 U/L) was higher than those in HT(4.8±2.3 U/L) and TFA(2.5±1.2 U/L)(p<0.01).Our findings suggest that the high expression of DCs' markers may be related to the pathogenesis of HT and GD.The upregulation of both the number and the matured functions of DCs,may lead to present more antigens and to produce more auto-antibodies(such as Tg-Ab and TPO-Ab in HT,TR-Ab in GD),which may be involved in pathogenesis of the autoimmune thyroid diseases.Cellular & Molecular Immunology.2004;1(5):378-382.