Correlation Between Von Willebrand Factor, Thrombin-Antithrombin Complex, and Disease Severity in Sickle Cell Disease: Implications for Thrombosis.

INTRODUCTION: Sickle cell disease (SCD) is a hypercoagulable state characterized by elevated procoagulant factors, including Von Willebrand factor (VWF), and enhanced thrombin generation, marked by increased thrombin-antithrombin complex (TAT). Research on VWF and TAT activity during vaso-occlusive crises (VOC) remains scarce in our region. OBJECTIVE: To determine VWF antigen and TAT complex serum levels in SCD during steady state and VOC, and correlate these with disease severity. METHODOLOGY: This cross-sectional study evaluated 30 SCD patients during VOC and re-evaluated the same cohort during their steady state. A control group of 30 HbAA individuals was included. Serum was analyzed for VWF and TAT complex. Analysis of Variance (ANOVA) and Pearson correlation tests were utilized (p < 0.05). RESULTS: Mean VWF levels were highest during VOC (500.9 ± 175.6 ng/mL), followed by steady state (421.5 ± 130.9 ng/mL) and controls (395.0 ± 115.2 ng/mL) (p=0.014). TAT complex levels were highest during VOC (28.9 ± 10.4 ng/mL) compared to steady state (24.1 ± 7.8 ng/mL) and controls (4.0 ± 4.2 ng/mL) (p<0.001). Steady-state VWF positively correlated with TAT (r = 0.458, p = 0.011), while steady-state TAT positively correlated with disease severity (r = 0.401, p = 0.028). CONCLUSION: VWF and TAT levels are significantly elevated in SCD patients, with further accentuation during VOC. These elevations strongly correlate with disease severity and specific clinical complications, establishing them as vital markers for evaluating thrombotic risk in SCD patients.