心肌肌钙蛋白Ⅰ自身抗体对心肌肌钙蛋白Ⅰ检测的影响及临床意义

The Effect and Clinical Significance of Cardiac Troponin I Autoantibody on the Detection of Cardiac Troponin I

目的 探讨心肌肌钙蛋白Ⅰ自身抗体(cTnIAAb)对心肌肌钙蛋白Ⅰ(cTnI)检测的干扰程度及其临床意义。方法 采用cTnI-TnC亲和层析柱纯化血清中的cTnIAAb,进行特异性鉴定;选取15例cTnI阳性样本(cTnI>0.026ng/mL),分别加入不同蛋白量的cTnIAAb,经cTnI检测系统测定cTnI原始浓度和回收浓度,计算cTnI下降率。结果 自身抗体阳性血清经亲和层析柱纯化得cTnIAAb 3.5mg,稀释后得cTnIAAb浓度为1ng/mL;cTnIAAb特异性实验中,随着加入cTnIAAb蛋白量增大,cTnI下降率逐渐升高,呈良好的多项式线性相关(R2=0.992);15例cTnI阳性样本,加入2μL cTnIAAb组出现cTnI低、中度降低血清分别为11份和4份;加入5μL cTnIAAb后出现cTnI低、中、高度降低的血清分别为2份、12份、1份;加入10μL cTnIAAb后出现cTnI中、高度降低的血清分别7份和8份;加入2μL、5μL、10μL cTnIAAb组lg(cTnI理论浓度)和cTnI下降率之间的相关系数r分别为-0.63(P<0.05)、-0.74(P<0.01)、-0.75(P<0.01),呈中等和强负相关关系。结论cTnIAAb可对cTnI检测产生明显的负性干扰,造成cTnI检测结果偏低,影响临床对心肌损伤类疾病的诊断。

Objective To investigate the interference degree of cardiac troponin I autoantibody(cTnIAAb)in the detection of cardiac troponin I(cTnI)and its clinical significance.Methods cTnIAAb was purified by cTnI-TnC affinity chromatography column,and its specificity was further identified.Fifteen cTnI positive samples(cTnI>0.026ng/mL)were selected for the study,and cTnIAAb with different amounts of protein were added respectively.The original concentration and recovery concentration of cTnI were determined by cTnI detection system,and the decline rate of cTnI was then calculated.Results The positive serum was purified by affinity chromatography to obtain 3.5mg cTnIAAb,and the concentration of cTnIAAb was 1ng/mL after dilution.cTnIAAb specificity test indicated that the decrease rate of cTnI gradually increased with the increase of cTnIAAb protein content,showing a good polynomial linear correlation(R 2=0.992).Of the 15 cTnI positive samples,11 and 4 were found in the 2μL cTnIAAb group,respectively.Low,medium and high levels of cTnI decreased in 2,12 and 1 serums after adding 5μL cTnIAAb,respectively.After addition of 10μL cTnIAAb,7 and 8 serums showed decreased cTnI medium and height,respectively.The correlation coefficients r between lg(cTnI theoretical concentration)and the decrease rate of cTnI in 2μL,5μL and 10μL cTnIAAb groups were-0.63(P<0.05),-0.74(P<0.01)and-0.75(P<0.01),respectively,showing a moderate and strong negative correlation.Conclusion cTnIAAb can significantly negatively interfere with cTnI detection,resulting in low cTnI detection results and affecting the clinical diagnosis of myocardial injury diseases.