Thrombotic Thrombocytopenic Purpura

• • Fever

  • Thrombocytopenic purpura

  • Hemolytic anemia

  • Neurologic abnormalities

  • Renal failure

Epidemiology

• • Cause is unknown: Believed to be autoimmune response to endothelial cell antigen in small vessels

  • It is most common between ages 20 and 50 years

  • The thrombocytopenia is probably due to a shortened platelet lifespan

  • The microangiopathic hemolytic anemia is produced by passage of RBCs over damaged small blood vessels containing fibrin strands

  • The anemia is often severe, and it may be aggravated by hemorrhage secondary to thrombocytopenia

Symptoms and Signs

• • Fever

  • Purpura and ecchymosis

  • Neurologic changes

  • -Headache

    -Confusion

    -Aphasia

    -Lethargy

    -Hemiparesis

    -Seizures

    -Coma

  • Hepatomegaly

  • Splenomegaly

  • Bleeding

Laboratory Findings

• • Thrombocytopenia

  • Anemia

  • Increased lactate dehydrogenase (LDH)

  • Normal prothrombin time (PT), partial thromboplastin time (PTT), international normalized ratio (INR)

  • Reticulocytosis

  • Increased bilirubin

  • Decreased haptoglobin

  • Negative Coombs test

  • Fragmented RBCs on peripheral smear

• • End-organ damage (renal failure, neurologic changes) due to occlusion of arteries and capillaries by hyaline membranes composed of platelets and fibrinogen

Rule Out

• • Other causes of thrombocytopenia and anemia

  • -Disseminated intravascular coagulation

    -Evan syndrome

    -Endocarditis

    -Vasculitis

• • CBC

  • PT, PTT, INR

  • LDH

  • Reticulocyte count

  • Serum bilirubin

  • Serum haptoglobin

  • Coombs test

  • Peripheral blood smear

When to Admit

• • Severe thrombocytopenia

  • Bleeding

  • Neurologic changes

  • Acute renal failure

When to Refer

• • All patients should be managed in consultation with a hematologist

• • Plasmapheresis with plasma exchange, corticosteroids, antiplatelet agents

  • Splenectomy can be used as an adjunct to medical treatment in order to reduce platelet and RBC loss

Surgery

Indications

• • As an adjunct to medical treatment

Medications

• • Corticosteroids

  • Antiplatelet drugs (aspirin and dipyridamole)

Treatment Monitoring

• • Platelet count

Complications

• • Renal failure

  • Neurologic changes

Prognosis

• • 65% remission with splenectomy alone

  • With combined therapy, prolonged remission can be achieved in most patients

References