N-methyl-D-aspartate–Receptor Antibodies, S100B Protein, and Neuron-Specific Enolase Before and After Cardiac Surgery: Association with Ischemic Brain Injury and Erythropoetin Prophylaxis

Abstract

Objective: To evaluate biomarkers of acute ischemic brain injury after surgical revascularization of the heart with the use of the heart-lung machine (ie, cardiopulmonary bypass [CPB]). Methods: Twenty consecutive patients were divided into 2 groups: the first 10 patients received a potential neuroprotective human recombinant erythropoietin and the remaining 10 comprised the control group. Neurological complications were monitored by measuring serum concentrations of N-methyl-D-aspartate (NMDA)– receptor antibodies (NR2Ab), S100B protein, and neuron-specific enolase (NSE) before and during the first 5 days after surgery, comparing the neurological outcome with the results of MRI examinations. Results: The results from the erythropoietin-treated group and the control group were similar, with a significant difference shown for the postoperative NSE. Comparison of serum concentrations of the biomarkers of 16 patients without brain ischemia and 4 patients with acute ischemia displayed significant differences for only postoperative NR2Ab, regardless if the patient received erythropoietin therapy. Conclusions: The analysis of NR2Ab serum concentrations might be useful for monitoring neuroprotective stroke treatment; however, further studies are required to investigate its role in acute ischemic brain injury.