Thrombotic Throbocytopenic Purpura
Causes and Risk Factors
Deficiency of metalloproteinase, responsible for breaking down vWF multimers
- congenital (ADAMTS-13)
- acquired: drugs, malignancy, HIV, idiopathic)
Signs, Symptoms, and Diagnosis
- history
- physical exam
- lab investigations
- diagnostic imaging
History
Neurological symptoms
- headache
- confusion
- focal deficits
- seizures
Lab Investigations
Renal failure: abnormal urinalyis, oliguria, ARF
CBC and
- PT and PTT normal
- hemolysis: inc uncong bili, LDH, dec haptoglobin
- negative Coombs' test
- BUN, creatinine
peripheral smear
- schistocytes and dec platelets
Diagnostic Imaging
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Pathophysiology
vWF is secreted by endothelial cells in a large polymer and is rapidly cleaved by ADAMTS-13.
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Treatments
Plasmapheresis and steroids are the treatments of choice. Plasma infusion should be given if plasmapheresis is not immediately available.
Do NOT give platelets, as this can increase rates of intravascular thrombosis.
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Consequences and Course
TTP rates of mortality are 90% if untreated.
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Resources and References