Table 2 Characteristics of two different ULVWF multimers

Synthesized in

Megakaryocytes

Endothelial cells

Stored in

α granules of platelets

Weibel-Palade bodies of ECs

Primary distribution at release

In circulation

On the membrane of ECs

Availability

In microcirculation

At ECs following endothelial exocytosis

Exposure to ADAMTS13

As platelet-adherent form

As ECs-adherent form

Interaction with platelets causing

Platelet aggregation and adhesion

Platelet-ULVWF strings

Localization of platelet-ULVWF complexes

Arteriolar and capillary lumens lodged as microthrombi in situ

Endothelial membrane-anchored as microthrombi strings

Example of leading its activity

ADAMTS13 autoantibody

Sepsis-induced endotheliopathy

Endotheliopathic lesion

Microthrombotic microangiopathy

Microthrombotic angiopathy

Hematologic manifestation

Thrombocytopenia and MAHA

Thrombocytopenia and MAHA/aMAHA

Associated inflammation

None to minimal (?)

Mild to severe

Associated clinical syndrome

TTP

TTP-like syndrome