Thrombotic Thrombocytopenic Purpura (TTP)
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þ Diagnosis
 - Clinical Pentad Symptoms:
  + thrombocytopenic purpura,
  + microangiopathic hemolytic anemia,
  + fluctuating neurologic symptoms,
  + renal disease, and
  + fever.
  However, only 40% of cases present with the classic pentad
  + 10-40 years (but see below)
  + 60% women
  + hematuria, proteinuria, maybe renal failure
  + fluctuating neuro symptoms
  fever and renal failure rare, so maybe talk about classic triad
  symptoms wax and wane
  more in obese females black with HIV on Plavix
  fatal unless treated, but treated mortality is 10%
  bottom line: check LDH and give FFP and
    no IVIG, no platelets (will make polymers longer and make patient worse)
    FFP vs PET (platelet exchange transfusion); PET works better, 
      takes away protease inhibitor
    FFP gives some protease that cleaves the polymers of platelets
  gross hematuria: think TTP and admit, consult hematology
 - ? if meningitis, sepsis
 - LDH level usually 5-6x higher than normal, from tissue response to
 - anemia, ^LDH and thrombocytopenia diagnostic for TTP even in absence of all
   clinical critera.
 - usually no inciting event found.
 - platelet and von Willebrand factor disorder; other clotting factors still
   OK
 - causes end-organ ischemia
 - do NOT give platelets!
 - Hemolytic-Uremic Syndrome similar but without (or with less)
   neurological symptoms;
 - Kids get O157:H7 HUS from 6 mo-1 year, different from usual HUS is less
   serious
 - Can send stool and urine for shiga toxin (most common cause), 
   but not serum test.
   
 - Plasma exchange removes the bad (and too big) von Willebrand factor,
   replace with FFP.

þ TTP Background
 - Some people consider thrombotic thrombocytopenic purpura (TTP)
   to be a more severe variant of hemolytic uremic syndrome (HUS).

þ TTP Etiology
 - E. coli 0157:H7 is generally associated with hemolytic uremic
   syndrome.  However, it can be a cause of thrombotic thrombocytopenic
   purpura.
   [Graeme KA, Kazzi AA (ed): "Thrombocytopenic purpura" in Emedicine by
   Plantz and Adler (eds.) http://www.emedicine.com/emerg/topic579.htm.]