[Hemorheologic parameters in patients with giant cell arteritis before and after treatment with steroids]

Basic hemorheological parameters like packed cell volume (PCV), plasma viscosity, red cell aggregation, red cell filterability and whole blood viscosity were measured in 18 patients (14 women, aged 75.4 years) with giant cell arteritis before and after treatment with steroids. The patient group was compared to controls (n = 27, age: 69.8 years) with matched age and cardiovascular risc factors. While no changes in red cell aggregation and filterability could be observed plasma viscosity was increased (1.59 +/- 0.14 mm2/s) by about 20%. The typical anemia of patients with giant cell arteritis (PVC: 0.38 +/- 0.05) prevented an increase in whole blood viscosity at high and medium shear rates (6.6 +/- 0.14 cP = mPas at 23/s). After a fortnight of systemic treatment with high doses of steroids the PCV had normalized and plasma viscosity was even lower than in controls. Thus the blood fluidity was improved as shown by a fall in whole blood viscosity (5.5 +/- 0.7 cP = mPas at 23/s). Results showed: (1) increased plasma viscosity probably induced by increased fibrinogen concentration and (2) an improvement in blood fluidity by treatment with steroids. As the plasma viscosity may participate in the deterioration of microcirculation in patients with giant cell arteritis, lowering the fibrinogen may possibly prevent a further decrease in visual acuity during the first few days of steroid treatment.