2 Lorrca aggregation measurement
Channel: Jan de Zoeten RRM
Date: 10/05/2015

RBC aggregation is an important, shear dependent, determinant of blood viscosity. Hyper aggregability can be detected in various diseases (e.g. inflammatory states, vascular pathologies and tissue perfusion problems). 

At low shear stress, RBC’s adhere side-to-side and end-to-end to form larger stacks, called rouleaux, followed by side-to-end connection creating 3D-aggregates (the rouleaux formation).

Measurement
Complete disaggregation of the RBC’s is induced by applying a high shear rate; followed by an abrupt stop, which causes the elongated and orientated RBC to retake their normal, biconcave, shape and orientate randomly. Then the aggregation process starts, at which rouleaux formation occurs. A syllectogram is created by plotting the laser back scattered intensity (Isc) versus time. By means of a photo diode (which measures the change in light back scatter) the total extent and kinetics of aggregation are displayed, as well as the minimal shear rate (threshold) needed to prevent RBC aggregation, i.e. the tendency for aggregation. For this test ~ 1 ml of whole blood is needed.

Lorrca Maxsis osmoscan is a unique instrument which combines Red Blood Cell (RBC) deformability by ektacytometry, osmoscan and aggregometry; all temperature controlled. It is capable of fully automated measurement and calculation of various phenomena of RBC’s by analysis of their rheological behavior. The technique accurately detects deformability as a function of shear stress, pre-hemolytic stability and aggregation of the RBC’s and is of added value for hematology analysis.