Snapshot
- A 21-year-old woman with past medical history of SLE presents with fever, fatigue, and altered mental status. On physical exam, a petechial rash is seen on her upper extremities. Her temperature is 103°F (39.4°C). Her labs are notable for Hgb 7.3 g/dL, platelets 17,000/mm3, and creatinine of 3.4 mg/dL.
Introduction
- Thrombotic microangiopathy characterized by a pentad
- microangiopathic hemolytic anemia
- acute renal failure
- thrombocytopenia
- fever
- neurologic abnormalities
- Similar to HUS but with fever and neurologic symptoms
- Epidemiology
- female > male
- most commonly in young adults
- Pathogenesis
- deficiency or inhibition of metalloproteinase ADAMTS13
- most commonly disabled by an autoantibody
- important underlying risk factor, but requires a secondary trigger
- triggers
- drugs (ticlopidine, clopidogrel, and cyclosporine)
- deficiency or inhibition of metalloproteinase ADAMTS13
- SLE
Presentation
- Symptoms (recall pentad)
- thrombocytopenia
- easy bleeding
- epistaxis
- neurological symptoms
- confusion
- seizures
- thrombosis
- renal dysfunction (less so than HUS)
- thrombocytopenia
- Physical exam
- fever
- pallor (from anemia)
- purpura/petechiae
- jaundice (from hemolysis)
- splenomegaly
Evaluation
- Complete blood count
- anemia
- thrombocytopenia
- Peripheral blood smear
- Serum
- ↑ LDH
- ↑ creatinine
- negative Coomb’s
- ↑ bleeding time
- normal PT/PTT
Differential Diagnosis
Treatment
- Plasma exchange transfusion with fresh frozen plasma
- Steroids
- Splenectomy
- Platelet transfusion contraindicated
- platelet transfusion will worsen disease by feeding the platelet consumption
Prognosis, Prevention, and Complications
- Prognosis
- remission with plasma exchange in majority of patients
- mortality rate 13-15%
- Complications
- permanent neurologic sequelae