Research On The Effect The Distribution Of Cytotoxic T Lymphoctyes In Viral Myocarditis

Viral myocarditis (VMC) is the viral infection disease,which is characterized bymyocardial inflammation. The clinical manifestations of the disease are very widely,from symptomless to heart failure and sudden death. In recent years, the incidence ofviral myocarditis in children, adolescents showed an increasingly trendence, VMC hasbecome an important reason for the sudden death in children, youth. Therefore, thestudy of viral myocarditis was concerned widely. So far, the pathogenesis of VMC hasnot been clearly explained yet.The Dallas standard which is used for diagnosed of VMCat home and abroad, but it is difficult to make a definitive diagnosis in some cases ofsudden death that have slightly myocardial changes and inflammation under lightmicroscope. Therefore, we need an effective and simple detection method for thediagnosis of myocarditis to clarify the cause of death,which becomes an urgent problemin Forensic Pathology. Studies have shown that in viral myocarditis the CTL mediatedcytotoxicity to myocardial cells,which has become the main reason for acute heartfailure. Researches have shown that osteopontin (OPN) was involved in thepathological process of cardiovascular disease.OPN expression enhanced activation andproliferation of inflammatory cells and mediated their chemotactic migration, resultingin severe myocardial injury which lead to heart failure. In addition, the recent foreignstudies have shown that matrix metalloproteinase-2(MMP-2) not only induce theexcessive degradation of normal myocardial collagen,which results in myocardialcollagen remodeling and myocardial fibrosis, but also as a powerful regulatory factor tomediate the immune cells migration and aggravate the development of lesion. Whileurokinase type plasminogen activator(uPA) as MMP activation factor indirectlyactivation to participate in the pathogenesis process it can also directly regulate theexpression of the immune cells, thereby contributing to the occurrence and developmentof the VMC. However,we can not know completely about the expression of OPN, uPA,MMP-2in case of sudden death due to viral myocarditis and their influences on CTL. Objective:The experiment is aimed at detecting the quantity of OPN, uPA,MMP-2and CD8in normal myocardium and myocarditis tissues, and then discussingthe effect of OPN, uPA, MMP-2on the CTL during developing myocarditis.Thiswork maybe offer an easy and practical way to the pathology diagnosis and analysis ofthe sudden death caused by viral myocarditis.Methods: The autopsy40cases,27males and13females, age6-72years old.The specimens based on the Dallas criterion were divided into definite myocarditisgroup (14cases),borderline myocarditis group (11cases) and normal myocardial group(15cases). Immunohistochemistry was used to detect the quantity of OPN,uPA, MMP-2,CD8in myocardial tissue, and the results were statistically analyzed.Results:1、OPN, uPA, MMP-2did not express or weakly express in normalmyocardium,and positive and strongly positive express in the borderline myocarditisand definite myocarditis, and mainly expressed in myocardial cells and inflammatorycells (macrophages and lymphocytes). The differences in the OPN, uPA,and MMP-2inthe three groups are statistically significant (P <0.05).2、CD8in normal myocardiumdid not express, but elevated express in the borderline myocarditis and definitemyocarditis group,the differences were statistically significant (P <0.05).3、TheSpearman correlation test analysis found that OPN,uPA, MMP-2, and CD8express inmyocarditis group showed a significant positive correlation.Conclusion:1、CD8is not expression in normal myocardial tissue, and the numberof this cell increaseing in myocarditise indicate CD8+T cells promote myocardialdamage, involveing in the development of virus myocarditis.2、OPN, uPA and MMP-2expressed slightly in normal myocardium, elevated inmyocarditis. Definite myocarditis group was significantly higher than the borderlinemyocarditis group, and the expression in the three substances were positivelycorrelated and have significant correlation on CD8,which indicate that OPN mayattimulate the expression of uPA, MMP-2, and promote CD8+T cell activation and tomediate their chemotaxis and migration to lesion area.