Evaluation of ADAMTS13 Activity and von Willebrand Factor Antigen Levels in Patients with Sickle Cell Anaemia

Abstract

Background: Sickle cell anaemia (SCA) is characterised by chronic haemolysis, inflammation, and recurrent vaso-occlusive crises, with endothelial dysfunction playing a central role in disease pathophysiology. von Willebrand factor antigen (vWF:Ag) and ADAMTS13 are key regulators of haemostasis, and their imbalance may contribute to microvascular thrombosis in SCA Aim: This study aimed to evaluate ADAMTS13 activity and von Willebrand factor antigen levels in patients with sickle cell anaemia. Method: This case–control study evaluated ADAMTS13 activity and vWF:Ag antigen levels among patients with sickle cell anaemia attending selected health centers in Ado-Ekiti, Ekiti State, Nigeria. A total of 60 participants were recruited, comprising 30 patients with sickle cell anaemia and 30 apparently healthy individuals who served as controls. The sickle cell patients included 16 patients in steady state and 14 patients experiencing sickle cell anaemic crisis. Venous blood samples were collected from all participants for the determination of ADAMTS13 activity and Vwf antigen levels using enzyme-linked immunosorbent assay (ELISA). Full blood counts were also performed using a Sysmex haematology Optimiza. Data analysis was carried out using the Statistical Package for Social Sciences (SPSS) version 26.0. Results were expressed as mean ± standard deviation. Analysis of variance (ANOVA) was used to assess differences among the study groups, while Tukey’s post hoc multiple comparison tests were applied to identify specific group differences. Statistical significance was set at p < 0.05. Results: The mean value of vWF:Ag of steady-state (207.64 ± 122.49 ng/mL) and crisis SCA patients (189.52 ± 100.47 ng/mL) was significantly higher compared with the control (60.92 ± 35.42 ng/mL). Steady-state patients showed significantly higher mean values than those in crisis (p < 0.001). ADAMTS13 activity was comparable across all three groups, with mean values of 0.83 ± 0.09 IU/mL in controls, 0.81 ± 0.17 IU/mL in steady-state patients, and 0.87 ± 0.14 IU/mL in crisis patients. No significant difference was observed among the groups (p = 0.428). Conclusion: The study concludes that vWF:Ag level is a better biomarker for the severity of the inflammatory endothelial vasculopathy, enhancing thrombotic complications than ADAMTS13Monitoring vWF levels may provide valuable insight into disease activity and severity, potentially informing clinical management and risk stratification of patients with sickle cell anaemia.