溶血标本的CK-MB活性检测异常结果研究

Study on hemolysis with the CK-MB activity assay

目的:探讨外周血标本溶血时肌酸激酶同工酶MB(CK-MB)活性相较于总肌酸激酶(creatine kinase,CK)活性显著升高的内在原因。方法:首先,按照溶血液在不溶血的血浆体积占比为0、0.1%、0.3%、1%、3%比例配制不同溶血程度的标本,使用南京大学医学院附属鼓楼医院常规生化试剂检测其中的CK-MB和总CK活性。随后,再使用该院干化学法、质量法及其它医院实验室的不同检测试剂与方法进行验证。此外,将该院常规化学CK-MB活性检测试剂盒中的不同浓度的CK-M亚单位抑制抗体加入溶血标本中,观察其对总CK活性的影响。最后,再回顾性分析本实验室CK-MB、CK活性检测与溶血指标的相关性。结果:溶血标本中CK-MB活性随溶血现象加剧而升高,最终CK-MB活性显著大于总CK活性。进一步验证比较发现,该现象仅存在于本实验室的常规化学方法中,不存在于干化学法、质量法以及其它公司的CK-MB活性检测方法中。CK-M亚单位抑制抗体对溶血标本的总CK活性无影响。回顾性数据分析结果显示,CK-MB/CK值升高的标本更易发生溶血。结论:溶血可导致CK-MB活性异常增高,此现象与厂家试剂盒中的CK-M亚单位抗体有关。因此,临床实验室须注意溶血对此检测的影响,做好相应的性能验证,并在必要时利用CK-MB质量法进行复查。

Objective:To confirm the cause that induces creatine kinase isozyme MB(CK-MB)activity being higher than total CK activity in serum samples with hemolysis.Methods:Routine and dry biochemical assays from different commercial reagent kits were used to detect CK-MB and total CK activity in serum samples with different ratios(0,0.1%,0.3%,1%,3%)of hemolysis.The protein level of CK-MB was determined by chemiluminescence immunoassays.Retrospective analysis was also performed on the previous data of our lab about potential interference of hemolysis with the CK and CK-MB activity assay.Results:The CK-MB activity increased with hemolysis and exceeded the total CK activity in samples with hemolysis by routine biochemical assay.However,this phenomenon was not observed in the detection with other assay methods and reagents.The blocking antibody CK-M subunits showed no influence on the total CK activity measurement.In the retrospective data analysis,samples with higher CK-MB/CK activity ratios showed higher risk with hemolysis.Conclusion:Hemolysis affects the CK-MB activity,which is due to the CK-M subunit antibody in the assay methods and reagents.Therefore,we should put an emphasis on CK-MB activity in hemolyzed serum samples and CK-MB protein level measurement is highly recommended to confirm contradictory results.