Difference between revisions of "Thrombotic thrombocytopenic purpura"

(Clarified diagnosis and minor aditions to pathophys)
Line 3: Line 3:
 
**Insufficient ADAMTS-13 activity allows vWF multimers to accumulate in microcirculation
 
**Insufficient ADAMTS-13 activity allows vWF multimers to accumulate in microcirculation
 
***Leads to platelet aggregation/thrombocytopenia and hemolysis of RBCs
 
***Leads to platelet aggregation/thrombocytopenia and hemolysis of RBCs
 +
****Platelet clots are transient, symptoms, especially neuro, can be in flux
 
*Similar to but different from [[HUS]] (which is more common in peds)
 
*Similar to but different from [[HUS]] (which is more common in peds)
 
*[[Microangiopathic Hemolytic Anemia (MAHA)]] + low plts is TTP until proven otherwise
 
*[[Microangiopathic Hemolytic Anemia (MAHA)]] + low plts is TTP until proven otherwise
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==Clinical Features==
 
==Clinical Features==
*Pentad
+
*Pentad (rarely all present)
 
#[[Microangiopathic Hemolytic Anemia (MAHA)]]
 
#[[Microangiopathic Hemolytic Anemia (MAHA)]]
 
#Thrombocytopenia
 
#Thrombocytopenia
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#Renal pathology
 
#Renal pathology
 
#CNS abnormalities (seizure, AMS, CVA, coma)
 
#CNS abnormalities (seizure, AMS, CVA, coma)
 +
*Neuro symptoms are often transient, may not be present in ED
  
 
*TTP pentad mnemonic = FAT RN
 
*TTP pentad mnemonic = FAT RN
 
**Fever, Anemia, Thrombocytopenia, Renal, Neuro sx
 
**Fever, Anemia, Thrombocytopenia, Renal, Neuro sx
 +
***All features do not need to be present at the same time
 +
 +
*Consider diagnosis without the full pentad
 +
**MAHA + Thrombocytopenia + any other feature
  
 
==DDX==
 
==DDX==
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**Indicated if plasma exchange cannot be performed immediately  
 
**Indicated if plasma exchange cannot be performed immediately  
 
**FFP  
 
**FFP  
 +
***Contains ADAMTS-13
 
**Platelet (only for life-threatening bleeding or intracranial hemorrhage)  
 
**Platelet (only for life-threatening bleeding or intracranial hemorrhage)  
 
***Platelet infusion may lead to acutely worsened thrombosis, renal failure, and death
 
***Platelet infusion may lead to acutely worsened thrombosis, renal failure, and death
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*Tintinalli
 
*Tintinalli
 
*Harwood Nuss
 
*Harwood Nuss
 +
*Rosens
 
[[Category:Heme/Onc]]
 
[[Category:Heme/Onc]]

Revision as of 14:45, 25 March 2014

Background

  • Pathophysiology
    • Insufficient ADAMTS-13 activity allows vWF multimers to accumulate in microcirculation
      • Leads to platelet aggregation/thrombocytopenia and hemolysis of RBCs
        • Platelet clots are transient, symptoms, especially neuro, can be in flux
  • Similar to but different from HUS (which is more common in peds)
  • Microangiopathic Hemolytic Anemia (MAHA) + low plts is TTP until proven otherwise
  • Can occur as a result of Plavix (clopidogrel) use (usually within first 2 wk of starting)

Risk Factors

  • Congenitally deficient ADAMTS-13 activity and:
  1. Pregnancy
  2. Infection
  3. Inflammation
  4. Medication use (quinolones, ticlopidine, clopidogrel)

Clinical Features

  • Pentad (rarely all present)
  1. Microangiopathic Hemolytic Anemia (MAHA)
  2. Thrombocytopenia
  3. Fever
  4. Renal pathology
  5. CNS abnormalities (seizure, AMS, CVA, coma)
  • Neuro symptoms are often transient, may not be present in ED
  • TTP pentad mnemonic = FAT RN
    • Fever, Anemia, Thrombocytopenia, Renal, Neuro sx
      • All features do not need to be present at the same time
  • Consider diagnosis without the full pentad
    • MAHA + Thrombocytopenia + any other feature

DDX

Work-Up

  • CBC with peripheral smear (anemia, schistocytes, thrombocytopenia)
  • LDH (elevated)
  • Haptoglobin (decreased)
  • Reticulocyte count (appropriate)
  • UA (hemoglobinuria)
  • Creatinine (possibly elevated)
  • LFTs (increased bilirubin)
  • PT/PTT/INR (normal; differentiates from DIC)
  • Urine pregnancy (significant association between pregnancy and TTP)

Treatment

  • Plasma exchange (plasmapheresis)
    • Replaces defective or insufficient ADAMTS-13 and clears vWF multimers
  • Transfusion
    • Indicated if plasma exchange cannot be performed immediately
    • FFP
      • Contains ADAMTS-13
    • Platelet (only for life-threatening bleeding or intracranial hemorrhage)
      • Platelet infusion may lead to acutely worsened thrombosis, renal failure, and death
  • Splenectomy - 2nd line therapy

Disposition

  • Admit for plasma exchange

See Also

Source

  • Tintinalli
  • Harwood Nuss
  • Rosens