Moderate heat treatment of only red blood cells (RBC) slows down the rate of RBC-RBC aggregation in plasma.

Rouleau formation by back scattered light and flow behaviour by viscometry of heat-treated (48.4, 48.8 and 49.5 degrees C) and normal (37 degrees C) human red blood cells (RBC) were investigated. Washed RBC were treated in PBS and afterwards resuspended in their own plasma. It was found that the time behaviour of the fibrinogen mediated weak RBC-RBC interaction is influenced (decreased) already at an incubating temperature of 48.4 degrees C. Kinetic measurements are more sensitive than a static aggregation characterization. Beside the decreased deformability of the RBC also a heat-altered structure of the RBC-glycocalyx and the aggregating energy of the macromolecules have to be considered.