A dextran-based warming method for preparing leukocyte-rich plasma and its clinical application for endotoxin assay

We devised a method using dextran for obtaining leukocyte-rich plasma (LRP) to measure endotoxin in blood. In order to find the optimal temperature for obtaining LRP, the measurement results were examined using samples prepared at 37 and 0°C. Sample separation time of LRP was significantly shorter at 37°C than at 0°C. Endotoxin measurement values showed a strong correlation between the two groups but many of the LRPs made at 37°C had measurements above those of the LRPs prepared at 0°C. The diagnostic accuracy for gram-negative bacterial infection was superior for LRP prepared at 37°C, with sensitivity and specificity of 96.8 and 100%, respectively. Plasma is usually used for measurement of blood endotoxin. Here, leukocyte-rich plasma (LRP) was obtained using an erythrocyte aggregation agent, dextran, and used for the assay. It was found that when LRP was separated at 37°C (referred to here as the LRP37 method), endotoxin values were higher than those obtained at 0°C (LRP0 method). The sensitivity and specificity of the LRP37 method were superior to those achieved using the LRP0 method.