自身免疫性心肌炎大鼠心肌病理改变与心肌标志物水平的相关性

目的 探讨N端前体脑钠肽(NT-proBNP)、肌钙蛋白I(cTnI)、肌酸激酶同工酶MB(CK-MB)在心肌炎诊断中的价值.方法 24只雄性Lewis大鼠完全随机分为对照组(n=12)和模型组(n=12).对照组大鼠皮下注射完全弗氏佐剂,模型组皮下注射心肌球蛋白诱导形成自身免疫性心肌炎.在初次免疫后第21天,进行心脏超声检测、血清cTnI、CK-MB、NT-proBNP水平检测及心肌组织病理学检查,并评价心肌炎变的严重程度,进行宏、微观病理评分.通过Logistic回归分析心肌炎病理评分与心肌标志物水平的相关性.结果 与对照组比较,心肌炎模型组大鼠左心室射血分数明显减弱(65.8±4.4)％比(86.9±1.1)％,P＜0.05],收缩末期内径明显增大(3.88±0.29) mm比(3.16±0.08)mm,P＜0.05]；CK-MB、cTnI及NT-proBNP都明显升高( 1357±397)IU/L比(392±120)IU/L,(17.2±5.3)μg/L比(6.8±1.8) μg/L,(706± 218) ng/L比( 110±46) ng/L,均P＜0.05].CK-MB与心肌病理宏观评分、微观评分均无明显相关性(P＞0.05),cTnI与心肌病理微观评分明显相关(P＜0.05),NT-proBNP与心肌宏观形态病理改变明显相关(P＜0.05).结论 CK-MB在一定程度上提示心肌损伤,但不能作为评价心肌炎症严重程度的指标；cTnI能够较好地提示心肌炎症细胞水平的严重程度,为心肌炎组织学水平病理改变的良好指标；NT-proBNP能够在形态学水平评价整体心肌损害的严重程度,但是在组织学水平其评价能力欠佳.

Relationship between histological findings and cardiac markers level in autoimmune myocarditis

Objective To evaluate the values of N-terminal pro-B-type natriuretic peptide （ NT-proBNP）, cardiac troponin I（cTnI） , creatine kinase-MB （CK-MB）and cardiac function, and to observe the relationship with histological findings in rat with experimental autoimmune myoearditis （EAM）. Methods Twelve Lewis rats were induced into control group by injection complete Freund＇s adjuvant; other twelve Lewis rats were induced into EAM by immunization with cardiac myosin. On the 21th day, cardiac function was evaluated by animal echocardiography, at the same day, we examined the changes of the cTnI, CK-MB and NT-proBNP and histological findings, score micro and macrohistologieal changes. Results Compared to the control group, the EAM rats had a significantly lower left ventricular ejection fraction （ 65.8 ± 4.4 ） % vs （ 86.9 ± 1.1 ） % , P 〈 0.05 ] and a larger left ventrieular endsystolic diameter （ 3.88 ± 0.29 ） mm vs （ 3.16 ± 0.08 ）mm, P 〈 0.05 ], and higher cTnI, CK-MB and NT-proBNP （392± 120） IU/L vs （ 1357 ± 397） IU/L, （6.8 ± 1.8 ）μg/L vs （ 17.2 ± 5.3） μg/L, （ 110 ± 46） ng/L vs （706 ± 218 ） ng/L, P 〈 0.05 ]. CK-MB was not correlated with histological changes （ P 〈0. 05 ）. cTnI was correlated with mierohistological changes （ P 〈 0.05 ）. NT-proBNP was correlated with macrohistologieal changes （ P 〈 0.05 ）. Conclusion NT-proBNP may be a prognostic marker of macrohistological changes and eTnI may be a prognostic marker of microhistological changes in autoimmune myoearditis.