The Significance Of The Apoptosis-associated Genes In Thymoma Tissue From Patients With Myasthenia Gravis

IntroductionThymoma is the frequent disease in TS.About 50%of patients with thymoma are concurrent with myasthenia gravis.It is very difficult to find the cause of myasthenia gravis concurrent with thymoma.The symptom of some patients will be the same or become worse after surgical treatment and that puzzle the patients and the doctors seriously.Especially in the clinical research,we found that some patients with thymoma are concurrent with myasthenia gravis and others are not concurrent with myasthenia gravis in despite of the sames in social factors(such as age,sex,social economic position,etc) and the changes of pathology(such as histological types,differentiation,etc),which makes us consider in the level of gene that the gene relative to autoimmune disease changed and lead to autoimmune function disorder because of the existence of thymoma or the thymus adjacent to the thymoma.In our study,we detect the expression levels of apoptosis-associated genes in thymoma tissue from patients with myasthenia gravis,to research the relation between apoptosis condition of myasthenia tissue cell and the occurrence of MG.We maybe find the origin of MG.Materials and Methods1.Materials (1) specimenThere were 23 patients in the thymoma with myasthenia gravis group.According to the WHO classification of thymomas(1999),3.10.5.3.2 patients had type A.AB.B1.B2.B3.All of them were treated as MG by neostigmine and electromyogram. Histological samples were treated as thymoma.As a control group,the thymoma without myasthenia gravis from 18 patients with congenital heart diseases was studied. 1.8.5.2.2 patients had type A.AB.B1.B2.B3.All patients were treated that they had not MG and other autoimmune diseases before operation and the thymus tissues were normal after operation.(2) Main agents,equipment and sourceAntibody of Fas,Bcl-2 protein,S-P kit and DAB kit were obtained from MAIXIN biological technology company in Fuzhou.Thermo Fisher scientific Lab Vision Autostainer 480.2.Methods(1)Detection of Fas,Bcl-2 by Immuohistochemical analysis S-P methods.Result determination:The overexpressed staining was in the cell membrane and cytolymph. The number of staining cells were graded as follows:10-24%(+);25-49%(++); 50-74%(+++);≥75%(++++).(2)Statistical analysisAll the datas were analysised with Wilcoxon analyses and the difference was significant(P＜0.05).Results1,HE dyeing of the sliceThe structure of normal thymic tissue is complete.The boundary between medulla and cortex is clear.There are lots of FT and adipose tissue among folials.The proportion of thymic FT is higher in thymic tissue from eld patients than that from younger patients.The tissue of thymoma composed the epithelium and lymphocyte and the proportion of the epithelium and lymphocyte was different.The epithelium was round or ovalis and the volumes of epithelium and lymphocyte were similar to each other.The epithelium was distributed among the thymus and the structure of the epithelium was single,the capacity of endochylema was few and the karyotin was light.2,Expression of Fas and Bcl-2The expressed staining of Fas and Bcl-2 was in the cell membrane and cytolymph.The staining cells of Fas and Bcl-2 were distributed among the thymus and the staining cells of Bcl-2 were mainly distributed among the medulla.The staining cells of Fas and Bcl-2 were distributed among the thymoma.The Fas mainly stained the epithelium and the Bcl-2 mainly stained the lymphocyte.Fas expressions were significantly higher in the thymoma with myasthenia gravis group than that in controls (Fas:u=3.802,P＜0.01;Bcl-2:u=2.873,P＜0.01).Bcl-2 expressions were significantly lower in the thymoma with myasthenia gravis group than that in controls (Bcl-2:u=2.873,P＜0.01).Conclusions1,It was significant difference in the express of Fas protein in cells between the thymoma with myasthenia gravis group and the thymoma without myasthenia gravis group.The result suggests that Fas may play an important role in the pathogenesis of myasthenia gravis concurrent with thymoma.2,Bcl-2 expression was significant lower in the thymoma with myasthenia gravis group compared with the thymoma without myasthenia gravis group.The result suggests that Bcl-2 may play an important role in the pathogenesis of myasthenia gravis concurrent with thymoma.