ADAMTS-13 Levels and Pathophysiology in the Different Thrombotic Microangiopathies (TMAs).
ADAMTS-13 Levels and Pathophysiology in the Different Thrombotic Microangiopathies (TMAs).
| Type of TMA | Pathophysiology | ADAMTS-13 Level During Acute Episode | |
|---|---|---|---|
|
| |||
| Activity | Anti-ADAMTS-13 Antibodies | ||
| Congenital TTP | ADAMTS-13 deficiency causes UL-VWF-platelet thrombi which lead to multi-organ ischemic failure | < 5% | Absent |
| Acquired TTP | Antibodies against ADAMTS-13 cause UL-VWF-platelet thrombi which lead to multi-organ ischemic failure | < 10% | Very High |
| Shiga-HUS | Shiga toxin causes secretion of UL-VWF and the formation of VWF-platelet thrombi in the glomerular microvasculature which lead to acute renal failure | > 20% | Absent |
| aHUS | Dysregulation of the complement system, mostly due to complement factor H deficiency, leads to VWF-platelet thrombi in the glomerular microvasculature and to acute renal failure | > 20% | Absent |
| HELLP syndrome and pre-eclampsia | Abnormal and hypoxic placenta activates the complement and coagulation cascades which lead to thrombotic microangiopathy | > 20% | Absent |
| Transplant and malignancy-associated TMAs | Endothelial toxicity causes thrombotic microangiopathy | > 20% | Absent |
| DIC | Disseminated intravascular coagulation activation leads to thrombotic microangiopathy and multi-organ ischemic failure | > 20% | Absent |
| Catastrophic antiphospholipid syndrome | Antiphospholipid antibodies cause endothelial damage, thrombotic microangiopathy, and multi-organ ischemic failure | > 20% | Absent |
ADAMTS-13, a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13; aHUS, atypical hemolytic uremic syndrome; DIC, disseminated intravascular coagulation; HELLP syndrome, hemolysis, elevated liver enzymes, and low platelets syndrome; Shiga-HUS, Shiga toxin-induced hemolytic uremic syndrome; TTP, thrombotic thrombocytopenic purpura; UL-VWF, ultra-large von Willebrand factor.