Titin and Ryanodine receptor epitopes are expressed in thymoma with myasthenia gravis patients / 中华神经科杂志

ABSTRACT

Objective To study the significance of Titin-ab and Ryanodine receptor-ab (RyR-ab) in the myasthenia gravis (MG) patients and the expression of Titin and RyR epitopes in thymoma of myasthenia gravis.Methods Using ELISA methods,the titer of the Titin-ab,RyR-ab in the sera of 62 patients with MG,as well as 45 cases non-MG with other neurologic disorders and 50 case of normal controls were determined,and Titin and RyR were studied with immunohistochemistry stain in the 19 samples of thymic tissues from 9 cases of MG with thymoma (MGT),6 cases of MG with thymic hyperplasia (MGH), 2 cases of MG with thymic atrophy (MGA),and 2 cases of non-MG with thymic carcinoma (NMGTC). Results The positive rate of Titin-ab in MG was 35.5% (22/62),with the highest being 82.3% (14/17) in MGT group.The positive rate of RyR-ab was 24.2% (15/62),the highest being 76.5% (13/17) in MGT group.Titin receptor epitopes were expressed in the transmembrane and cytoplasm region of thymoma epithelial cells of 7 cases of MGT patients,and RyR epitopes in the transmembrane region of thymoma epithelial cells of 6 cases of MGT;but no Titin nor RyR epitopes was identified in controls and such thymic pathological patterns,as MGH,MGA,NMGTC.Conclusions Titin-ab and RyR-ab are mostly found in MGT patients;Titin and RyR epitopes are expressed in neoplasm epithelial cells of thymoma with myasthenia gravis;it's a result of autoimmunization of Titin and RyR epitopes irritated by Titin and RyR specific T cells activated by the change of pathogenic microenvionment inside the thymoma.