ADAMTS13 activity to von Willebrand factor antigen ratio predicts acute kidney injury in patients with COVID-19: Evidence of SARS-CoV-2 induced secondary thrombotic microangiopathy

Int J Lab Hematol. 2021 Jul;43 Suppl 1(Suppl 1):129-136. doi: 10.1111/ijlh.13415. Epub 2020 Dec 3.


Introduction: Severe COVID-19 is often compounded by a prothrombotic state that is associated with poor outcomes. In this investigation, we aimed to evaluate ADAMTS13 activity, von Willebrand factor level (VWF:Ag), and the corresponding ADAMTS13 activity/VWF:Ag ratio, in patients with COVID-19 and for associations with disease progression and acute kidney injury (AKI).

Methods: Patients presenting to the emergency department (ED) with COVID-19 were enrolled in this prospective, observational study. ADAMTS13 activity and VWF:Ag were measured at index ED visit. The primary endpoint was severe AKI defined by KDIGO stage 2 + 3 criteria, while the secondary endpoint was peak 30-day COVID-19 severity.

Results: A total of 52 adult COVID-19 patients were enrolled. Overall, we observed that 23.1% of the cohort had a relative deficiency in ADAMTS13 activity, while 80.8% had elevated VWF:Ag. The ADAMTS13 activity/VWF:Ag ratio was significantly lower in patients with severe AKI (P = .002) and those who developed the severe form of COVID-19 (P = .020). The ADAMTS13 activity/VWF:Ag ratio was negatively correlated with age (P < .001) and LDH (P < .001), while positively correlated with hemoglobin (P = .041). After controlling for confounders, a one-unit increase in ADAMTS13/VWF:Ag ratio was associated with 20% decreased odds of severe AKI.

Conclusion: A low ADAMTS13 activity:VWF:Ag ratio at ED presentation is associated with progression to severe COVID-19 disease and severe AKI, with a pattern suggestive of a secondary microangiopathy. Further interventional studies should be conducted to assess the restoration of ADAMTS13:VWF:Ag ratio in hospitalized patients with COVID-19.

Keywords: ADAMTS13; acute kidney injury; coagulopathy; outcome; thrombosis; von Willebrand factor.

Publication types

  • Observational Study

MeSH terms

  • ADAMTS13 Protein / blood*
  • ADAMTS13 Protein / deficiency
  • Acute Kidney Injury / blood*
  • Acute Kidney Injury / etiology
  • Adult
  • Aged
  • COVID-19 / blood*
  • COVID-19 / complications
  • Comorbidity
  • Female
  • Humans
  • Male
  • Middle Aged
  • Prognosis
  • Prospective Studies
  • SARS-CoV-2*
  • Severity of Illness Index
  • Thrombophilia / etiology
  • Thrombotic Microangiopathies / etiology*
  • von Willebrand Factor / analysis*


  • von Willebrand Factor
  • ADAMTS13 Protein
  • ADAMTS13 protein, human