Table 3.
Hematologic and Clinical Characteristics of endotheliopathy-associated DIT and true DIC
| EA-DIT/VMTD and “DIC” of McKay | True DIC | |
|---|---|---|
| Example | TTP-like syndrome | APL |
| Nature of the clots | “Microthrombi strings” made of platelet-ULVWF complexes | “Fibrin clots” made of fibrin meshes |
| Mechanism of the genesis | Intravascular microthrombogenesis | Intravascular fibrinogenesis |
| Inciting causes/events | Infection; surgery; pregnancy; transplant; cancer; drug; toxin, leading to edotheliopathy | APL, leading to TF expression |
| Hematological manifestation | Microthrombotic disorder | Hemorrhagic disorder |
| Pathogenesis | ||
| Mechanism | Activation of microthrombotic pathway | Activation of TF-initiated coagulation cascade |
| Site of activation | Intravascular membrane of ECs | In circulation |
| Thrombopathic result | Intravascular hemostasis of ULVWF path | Consumption of fibrinogen, FV and FVIII |
| Effect on the involved organ | Hypoxic organ dysfunction | Generalized bleeding tendency |
| Coagulation tests | ||
| Fibrinogen | Normal | Decreased |
| PT; aPTT; TT | Normal | Prolonged |
| FVIII activity | Normal or markedly increased | Markedly decreased |
| Thrombocytopenia | Mild to moderately severe | Not consumed but decreased due to APL |
| Associated clinical syndrome | MODS; cytokine storm; SIRS | Hemorrhagic syndrome |
| Associate hematologic features | ||
| Schistocytes | Often present | Absent |
| MAHA/aMAHA | Almost always present | Does not occur |
| Hepatic coagulopathy | Common | Does not occur |
| Incidence in clinical practice | Very common | Extremely rare |
| Management | ||
| Platelet transfusion | Contraindicated | May be used if needed for APL |
| Treatment | TPE; rADAMTS13 (expected to be very effective) | Treat underlying pathology (e.g., ATRA in APL) |
APL acute promyelocytic leukemia, aPTT activated partial thromboplastin time; ATRA All-trans retinoic acid, DIC disseminated intravascular coagulation; DIT disseminated intravascular microhrombosis; FDP fibrin degradation products, FVIIa activated factor VII, FVIII factor VIII; MAHA/aMAHA microangiopathic hemolytic anemia/atypical MAHA, MODS, multi-organ dysfunction syndrome, PT, prothrombin time; rADAMTS13 recombinant ADAMTS13, SIRS systemic inflammatory response syndrome, TF tissue factor, TMA thrombotic microangiopathy; TPE therapeutic plasma exchange; TTP thrombotic thrombocytopenic purpura, ULVWF unusually large von Willebrand factor multimers; VMTD vascular microthrombotic disease