Influence of Hemolysis on the Measurement of S-100β Protein and Neuron-specific Enolase Plasma Concentrations during Coronary Artery Bypass Grafting

[摘要] Cerebral injury is an important complication after cardiovascular surgery. The neurological events usually are diagnosed using rather crude psychometric tests and clinical observations (1). Biological markers have been proposed to detect cerebral damage during cardiac surgery, e.g., the creatine kinase BB isoform or neuron-specific enolase (NSE). Because of its neurospecificity, the γγ isoform of enolase is of particular interest. Measurements in biological fluids use γ-subunit-specific immunoassays. Because of the abundance of the αγ isoform of enolase in erythrocytes, systemic NSE values may be falsely increased by the frequent hemolysis that occurs during surgery (2)(3).S-100β protein (S-100) is a member of a family of calcium-binding proteins present primarily in nervous tissue, where it is concentrated mainly in glial cells. Although the role of this protein in brain function and disease has not been elucidated conclusively, it has been ascertained that the appearance of this protein constituent of neural cells in biological fluids is a reliable indicator of active cell damage in the nervous system in different pathological conditions. Measurement of S-100 in the blood recently has been used successfully to monitor cerebral damage after cardiac surgery (4)(5)(6). S-100 is absent from red blood cells (RBCs), and plasma concentrations would not be influenced by hemolysis.We examined the reliability of measurements of plasma S-100 in either in vivo or ex vivo hemolyzed blood samples. Blood samples were taken from 24 patients (19 males and 5 females; age, 63.4 ± 9.8 years, mean ± SD), who were undergoing coronary artery bypass grafting (CABG) with cardiopulmonary …

[学科分类] 过敏症与临床免疫学