Haemorheological changes in patients with systemic lupus erythematosus do not seem to be related to thrombotic events

Atherothrombotic events are significant factors of mortality and morbidity in patients with systemic lupus erythematosus (SLE). The extent that rheological factors may be involved in these events in these patients has not been established. We measured the following rheological parameters in 86 patients with SLE, of whom 16 had suffered venous and/or arterial thrombotic events, and in 86 healthy controls: fibrinogen (Fbg), plasma viscosity (PV), blood viscosity at 230 s(-1) both at native haematocrit (BVn 230 s(-1) and corrected to 45% (BVc 230 s(-1), erythrocyte aggregation at stasis (AE0) and at 3 s(-1) (AE1), aggregation time (Ta), aggregation index at 10 s (AI10), disaggregation threshold (gammaD), and erythrocyte deformability (ED). In addition glucose, total cholesterol (T-Chol), triglycerides (TG), haematocrit (Hct) and Body Mass Index (BMI) were determined. SLE Disease Activity Index (SLEDAI) was also assessed. The patients showed a significant increase in BMI (P=0.030), TG (P<0.001), PV (P=0.007), AE0 (P=0.005), AE1 (P=0.006), AI10 (P=0.024), gammaD (P=0.001), Fbg (P=0.050); and a significant decrease in Ta (P<0.001), Hct (P<0.001) and BVn 230 s(-1) (P=0.003). When patients with SLEDAI10 were compared, the latter had lower Hct (P=0.041) and lower BVn 230 s(-1) (P=0.017) than those with less SLEDAI. No significant differences were found in any of the parameters analysed on comparing patients who had suffered a thrombotic event with those who had not. Our results suggest that, although patients with SLE have moderate rheological changes, these do not seem to be responsible for the increase in the thrombotic tendency in these patients.