Influence of fibrinogen levels on erythrocyte aggregation determined with the Myrenne aggregometer and the Sefam erythro-aggregometer.

ABSTRACT

Fibrinogen is one of the plasmatic proteins which has a major influence on erythrocyte aggregation. The level of fibrinogen at which erythrocyte aggregation does not further increase is not well established. Therefore we aim to determine erythrocyte aggregation with two devices Myrenne aggregometer (M0 and M1) and Sefam erythro-aggregometer (Ta, AI10 and gammaD) in relation with fibrinogen levels, in patients with several diseases with fibrinogen levels ranging between 200-1100 mg/dl. With the Myrenne aggregometer a plateau can be observed for fibrinogen levels higher than 400 mg/dl, while with the Sefam erythro-aggregometer, aggregation increases proportionally with fibrinogen levels higher than 400 mg/dl. In addition, for fibrinogen values higher than 400 mg/dl, only statististically significant correlations could be observed between fibrinogen and erythrocyte aggregation parameters with the Sefam erythro-aggregometer r(Ta)=-0.463; r(AI10)=0.624, r(gammaD)=0.817, p<0.01, but not with the Myrenne r(M0)=0.01, r(M1)=0.02, ns. Although the Sefam erythro-aggregometer is a better tool for determining erythrocyte aggregation both at low and high fibrinogen levels, the Myrenne aggregometer may be useful for assessing the erythrocyte aggregation as an indicator of cardiovascular risk, as in such circumstances fibrinogen levels do not usually exceed values higher than 400 mg/dl.