病毒性心肌炎与扩张型心肌病心肌线粒体DNA缺失的定量分析

目的对比研究病毒性心肌炎(VMC)与扩张型心肌病(DCM)患者活检心肌组织线粒体DNA(mtDNA)缺失突变情况及其与外周淋巴细胞mtDNA缺失程度的相关性.方法用定量PCR法检测20例VMC患者、12例DCM患者心肌细胞及其外周血淋巴细胞mtDNA4977碱基对(mtDNA4977)和mtDNA7436碱基对(mtDNA)缺失率.取12例健康意外死亡者心肌和23例献血员外周血淋巴细胞作正常对照.结果正常对照者、VMC和DCM患者心肌细胞均存在mtDNA4977及mtDNA7436缺失,合计缺失率分别为0.175%、0.385%和3.004%;外周淋巴细胞mtDNA缺失程度与心肌细胞呈一致性改变,且有良好的相关性(r=0.960,P＜0.001).结论mtDNA缺失可能是VMC发病及其向DCM演变的一个重要心肌损伤机制;外周淋巴细胞在研究心肌细胞mtDNA缺失中的作用值得进一步探讨.

Quantitative abnalysis if mittochondraial DNA deletions in myocardial biopsy samples form patients with viral myocarditis and dilated cardlimyopathy

Objective To investigate the mitochondrial DNA (mtDNA) deletions in myocardial biopsy samples in patients with viral myocarditis (VMC) and dilated cardiomyopathy (DCM),and the relation between mtDNA deletions and peripheral lymphocytes. Methods mtDNA4977 base pair (mtDNA 4977 )and mtDNA7436 base pair(mtDNA 7436 )deletion rates of myocytes and lymphocytes were measured by the method of quantitative PCR in 20 VMC patients, 12 DCM patients and 35 control cases (12 myocardial samples from the healthy cases died of accident, 23 blood samples of lymphocytes from the blood donators). Results mtDNA 4977 and mtDNA 7436 deletions were observed in both controls (0.175%) and patients with VMC (0.385%) and DCM(3.004%). The severity of mtDNA deletions in VMC and DCM cases were 1.2 and 16.2 times higher than in normal subjects. mtDNA deletion rates in patients with DCM were 6.8 times higher than that in patients with VMC ( P <0.05). The degree of mtDNA deletions in peripheral lymphocyte was similar with and showed well correlation with that in myocardium ( r =0.960, P <0.001). Conclusions mtDNA deletions in myocardium might play an important role in the pathogenesis of VMC as well as its development to DCM. The value of peripheral lymphocyte in the study of myocardial mtDNA deletion needs to be further investigated.