Increased erythrocyte adhesiveness and aggregation in peripheral venous blood of women with pregnancy-induced hypertension

OBJECTIVE: To study the state of erythrocyte adhesiveness/aggregation in th e peripheral blood of women with pregnancy-induced hypertension as well as in matched controls using a simple slide test and image analysis. METHODS: We recruited 25 women with pregnancy-induced hypertension. Twenty- five age- and gestational age-matched normotensive volunteers took part in die study and served as controls. Blood smears were evaluated by an image a nalysis system (INFLAMET). Quantitative measures of erythrocyte aggregation were used to describe the state of erythrocyte adhesiveness/aggregation su ch as vacuum radius, which measures the spaces between the aggregated eryth rocytes. The number of participants was established by power analysis (give n a of 0.05 and 80% power and considering a minimum difference to detect 4 mum in vacuum radius with a standard deviation of approximately 5). RESULTS: A significant (P = .002) increment in the state of erythrocyte agg regation was noted in the study group compared with the controls, the vacuu m radius values being 16.1 +/- 1.3 and 10.3 +/- 1.2, respectively. Erythroc yte sedimentation rate but not fibrinogen concentration was significantly e levated in the study group. The increased aggregation correlated significan tly with fibrinogen concentration, systolic, and diastolic blood pressures. CONCLUSION: We observed increased aggregability of red blood cells in hyper tensive conditions of pregnancy. Our findings are significant in that they reveal blood pressure-related increment in red cell adhesiveness/aggregatio n despite there being no significant increment in clotable fibrinogen conce ntrations. (C) 2001 by the American College of Obstetricians and Gynecologi sts.