Distinguishing features of microangiopathic hemolytic disorders
| Clinical and lab features . | CAPS . | TTP . | ST-HUS . | CM-TMA . | HIT . | DIC . |
|---|---|---|---|---|---|---|
| PMHx | Prior diagnosis of APS, SLE | Previous TTP (hereditary or immune) | Hereditary CM-TMA | |||
| Trigger | Infection, surgery, trauma, malignancy, pregnancy, SLE, anticoagulation discontinuation, estrogen exposure | Pregnancy, infection, drugs, estrogen exposure | Shigella or E. coli 0157:H7 infection | Pregnancy, transplant, drugs, malignant hypertension | Heparin exposure, surgery | Sepsis, surgery, trauma, malignancy, obstetric complications |
| Multiorgan involvement | + | + | + | + | + | + |
| Predominant organ system involvement | Renal, resp, cardiac, CNS | CNS, cardiac, GIT, renal | Renal, GIT | Renal, GIT, CNS | Renal, lungs, skin | |
| Disease course | Within 1 wk | Days | Days | Days | Days | Days |
| Vessel involvement | Small and large | Small | Small | Small | Small and large | Small and large |
| Laboratory tests | ||||||
| DAT (−) hemolytic anemia | +/− | + | + | + | +/− | +/− |
| Schistocytes | +/− | + | + | + | +/− | +/− |
| Thrombocytopenia | Moderate/severe | Moderate | Moderate | Moderate | Moderate | Moderate/severe |
| Fibrinogen | Normal | Normal | Normal | Normal | Normal | Low |
| aPTT | Normal/prolonged | Normal | Normal | Normal | Prolonged | Prolonged |
| Serum ferritin | Elevated | Elevated | Elevated | Elevated | Elevated | Elevated |
| D-dimer | Elevated | Elevated | Elevated | Elevated | Elevated | Elevated |
| Distinguishing laboratory tests | +aPL microvascular ischemia on tissue biopsy | Low ADAMTS13 | Positive Shiga toxin/STEC | Elevated complement levels (C3, C4, CH50, C5-9a), complement mutations | Positive anti-PF4 antibody and SRA | Reduction of all clotting factors |
| Clinical and lab features . | CAPS . | TTP . | ST-HUS . | CM-TMA . | HIT . | DIC . |
|---|---|---|---|---|---|---|
| PMHx | Prior diagnosis of APS, SLE | Previous TTP (hereditary or immune) | Hereditary CM-TMA | |||
| Trigger | Infection, surgery, trauma, malignancy, pregnancy, SLE, anticoagulation discontinuation, estrogen exposure | Pregnancy, infection, drugs, estrogen exposure | Shigella or E. coli 0157:H7 infection | Pregnancy, transplant, drugs, malignant hypertension | Heparin exposure, surgery | Sepsis, surgery, trauma, malignancy, obstetric complications |
| Multiorgan involvement | + | + | + | + | + | + |
| Predominant organ system involvement | Renal, resp, cardiac, CNS | CNS, cardiac, GIT, renal | Renal, GIT | Renal, GIT, CNS | Renal, lungs, skin | |
| Disease course | Within 1 wk | Days | Days | Days | Days | Days |
| Vessel involvement | Small and large | Small | Small | Small | Small and large | Small and large |
| Laboratory tests | ||||||
| DAT (−) hemolytic anemia | +/− | + | + | + | +/− | +/− |
| Schistocytes | +/− | + | + | + | +/− | +/− |
| Thrombocytopenia | Moderate/severe | Moderate | Moderate | Moderate | Moderate | Moderate/severe |
| Fibrinogen | Normal | Normal | Normal | Normal | Normal | Low |
| aPTT | Normal/prolonged | Normal | Normal | Normal | Prolonged | Prolonged |
| Serum ferritin | Elevated | Elevated | Elevated | Elevated | Elevated | Elevated |
| D-dimer | Elevated | Elevated | Elevated | Elevated | Elevated | Elevated |
| Distinguishing laboratory tests | +aPL microvascular ischemia on tissue biopsy | Low ADAMTS13 | Positive Shiga toxin/STEC | Elevated complement levels (C3, C4, CH50, C5-9a), complement mutations | Positive anti-PF4 antibody and SRA | Reduction of all clotting factors |
CM-TMA, complement-mediated thrombotic microangiopathy; CNS, central nervous system; DAT, direct antigen test; GIT, gastrointestinal tract; HIT, heparin-induced thrombocytopenia; PMHx, past medical history; STEC, Shiga toxin–producing E coli; SRA, serotonin release assay; TTP, thrombotic thrombocytopenic purpura.