Evaluation of von Willebrand Factor Levels in Sickle Cell Patients Attending Babcock University Teaching Hospital

Introduction: von Willebrand Factor (VWF) plays a vital role in platelet aggregation. The unusually large VWF multimers mediate the adhesion of sickle red blood cell (RBC) to endothelial cells and contribute to vaso-occlusive episodes.

Objective: The aim of this study was to determine if there is a correlation between VWF and disease severity in sickle cell Disease.

Methods: The Babcock University Health Research Ethical committee approved the study. Fifty (50) subjects and 13 controls were recruited into this cross-sectional study. 22 patients presented during steady state while 28 patients presented during vaso-occulssive crisis. Five (5) ml of venous blood was collected. 2 ml was transferred into an Ethylene Diamine Tetra Acetic Acid (EDTA K3) bottle at a concentration of 1.2 mg of anhydrous salt per ml of blood. This was used for blood counts. Three ml of blood was added into 3.2% trisodium citrate in 5% HEPES at a concentration of 9 parts of blood to 1 part of the anticoagulant for the measurement of VWF: Ag level.

Results: The mean values of VWF in crisis state (143.8±28.00) and steady state (105.68±21.43) were higher than that of the control (78.30±28.10). There was a significant difference in platelet (p<0.000) count among the groups: crisis state has the highest mean value (370.64±128.78), followed by the steady state (333.04±120.47), and the control group (221.23±91.34).

Conclusion: Severity of sickle cell disease increases with elevation of VWF level in the plasma of patients in crisis state than those in the steady state. This is as a result of the contribution of VWF and the platelets in the formation of microthrombi.