Effects of fibrinogen, globulin, albumin and hematocrit on the kinetics of erythrocyte aggregation in man.

The effects of fibrinogen, globulin, albumin, and packed blood cell volume (hematocrit) on the kinetics of erythrocyte aggregation (RBC-A) after stasis were quantitatively evaluated by recording the changes of light transmission through the blood in transparent tubing with an apparatus consisting of a light-emitting diode and a silicon photodiode. The measurements were done on samples of heparinized whole blood, suspensions of erythrocytes containing various concentrations of fibrinogen (0.5 to 25 g/L) or gamma globulin (25 to 150 g/L), and blood of various hematocrit values prepared from three samples of whole blood having different concentrations of fibrinogen. The half-time of the increase of light transmission after the flow-stop was used as an index of the kinetics of RBC-A (T1/2). This simple and rapid method for estimating erythrocyte aggregation had excellent reproducibility (N = 51, r = 0.99). The values of T1/2 showed significant negative correlations with the concentrations of fibrinogen and globulin but a positive correlation with that of albumin. The T1/2 value decreased markedly and then remained almost constant with increase in the value of hematocrit, but the influence of hematocrit on T1/2 was markedly dependent on the concentration of fibrinogen.