Viscosimetric effect of fibrinogen.

AIMS--To investigate the correlation between fibrinogen concentration and plasma and serum viscosity. METHODS--Measurements of paired plasma viscosity and serum viscosity were compared in 45 subjects with a considerable range of fibrinogen concentrations and serum viscosity. RESULTS--Plasma and serum viscosity correlated well with plasma fibrinogen in cases of normal serum viscosity, but not in cases of myeloma or macroglobulinaemia. When an exponential correlation between plasma and serum viscosity was used, fibrinogen showed a good correlation in both normal and abnormal conditions. CONCLUSIONS--There is an exponential correlation between plasma and serum viscosity which depends on the plasma fibrinogen concentration. This is in accordance with Arrhenius's formula for solutions of varying concentrations.