Lack of association between hemorheological alterations and upper-extremity deep vein thrombosis.

INTRODUCTION: There is an association between rheological alterations and lower extremity deep vein thrombosis, although no research has been carried out regarding the possible influence of rheological alterations in the development of venous thrombosis in the upper limbs. MATERIALS AND METHODS: We have determined in 54 patients (23 male, 31 female; aged 35+/-11 years) with primary upper extremity deep vein thrombosis (UEDVT), and in a well matched control group of 87 subjects (41 male, 46 female; aged 36+/-12 years) the rheological profile (blood viscosity, plasma viscosity, fibrinogen, erythrocyte aggregation, erythrocyte deformability) along with plasma lipids (total cholesterol and triglycerides) and body mass index (BMI). Thrombophilic defects (antithrombin, protein C, protein S deficiencies, factor V Leiden, prothrombin G20210A mutation and antiphospholipid antibodies) were also determined. RESULTS: No statistical differences were observed in any of the rheological parameters analyzed (p>0.05), as well as in plasma lipids and BMI (p>0.05) when cases and controls were compared. In investigating the associated factors, we found that more than 60% of events could be explained through effort (28%), thrombophilic defects (19%) and oral contraceptives (26%). Obesity and hyperlipidaemia were not associated with primary UEDVT. CONCLUSION: Hemorheological alterations do not seem to contribute from a pathogenic point of view to the development of thrombotic events in this infrequent venous location, which is in accordance both with the absence of cardiovascular risk factors and the high shear forces existing in the upper extremity.

Erythrocyte aggregability and AB0 blood groups.

It is not established whether there is an association between erythrocyte aggregation and AB0 blood type, as glycophorins carry sialic acid which is responsible for the negative erythrocyte surface charge and the antigenicity for AB0 blood groups. We have determined erythrocyte aggregation by means of the Myrenne aggregometer in 114 healthy volunteers, along with plasma lipids, fibrinogen and AB0 blood groups. No differences in erythrocyte aggregation (EA0 and EA1) were observed when subjects with 0 (n = 45) and non-0 (n=69) blood group were compared (P = 0.624 and P = 0.838, respectively). Fibrinogen was statistically lower in 0 group compared with non-0 group (P = 0.012). Erythrocyte aggregation (EA0 and EA1) correlated significantly with both lipids and fibrinogen (P < 0.01). When erythrocyte aggregation was dichotomized as EA1 > or = 8, no association was found with 0 and non-0 blood groups (P > 0.05) but it was associated with high lipid levels: T-Chol > 220 mg/dl, TG > 175 mg/dl and high fibrinogen levels > 300 mg/dl (P = 0.035; P = 0.030; P = 0.010, respectively). Erythrocyte aggregation does not seem to be associated with blood groups, but rather with plasma lipids and fibrinogen.