Résumé
Sickle cell disease (SCD) is characterized by vaso‐occlusive crisis (VOC), acute chest syndrome (ACS) and multiorgan failure (MOF) complicated by thrombosis. Von Willebrand factor (VWF) is a strong marker of SCD‐related endothelial injury.
To decipher the role of VWF and its specific‐cleaving metalloprotease, ADAMTS13, in the vaso‐occlusive and thrombotic process of SCD.
We investigated the VWF antigen (Ag), ADAMTS13 activity, ADAMTS13 Ag and ADAMTS13 IgGs in a cohort of 65 patients with SCD prospectively enrolled in a 20‐month period from three centers. Patients were divided into two groups: an asymptomatic group (n = 30) with treated or untreated SCD at steady state, and a VOC/ACS group (n = 35) with SCD with VOC/ACS requiring either medical management or intensive care management for MOF.
VWF:Ag levels were increased (median, 167 IU/dL; interquartile range [IQR], 124 ‐ 279), especially in patients with VOC SCD (227 IU/dL; IQR, 134‐305; P = .04), and positively correlated with inflammatory markers (P < .02). Median ADAMTS13 activity was normal (70 IU/dL; IQR, 60‐80), but 7 patients exhibited a partial deficiency between 25 and 45 IU/dL. ADAMTS13 activity/VWF:Ag ratio, however, did not change during VOC. Median ADAMTS13:Ag was slightly decreased (611 ng/mL; IQR, 504‐703) with no significant difference between groups. Surprisingly, ADAMTS13 IgGs were detected in 33 (51%) of our patients. We conclude that, in SCD, VWF:Ag and nonrelevant ADAMTS13 IgGs may reflect the severity of the inflammatory vasculopathy enhancing vaso‐occlusive and thrombotic complications.