Thrombotic thrombocytopenic purpura
TTP is a subtype of the thrombotic microangiopathy (TMA) syndromes. Other subtypes of TMA include Shiga toxin-mediated TMA (Shiga toxin hemolytic-uremic syndrome), drug-mediated TMA, and complement-mediated TMA, among others. Accurate diagnosis of TTP and prompt initiation of treatment are essential to prevent morbidity and mortality.
The cause may be acquired or, in rare cases, hereditary (Upshaw-Schulman syndrome). In acquired TTP, autoantibodies form against ADAMTS13, which normally cleaves von Willebrand factor (vWF). As a result, vWF multimers accumulate, causing platelet aggregation and microvascular occlusion. Upshaw-Schulman syndrome results from genetic mutations in the ADAMTS13 gene.
Classically, TTP was thought to be associated with a "pentad" of clinical and laboratory findings including microangiopathic hemolytic anemia, thrombocytopenia, neurologic abnormalities, fever, and renal dysfunction. However, the latter 3 findings are not reliably present in TTP, and consequently the presence of microangiopathic hemolytic anemia and thrombocytopenia are sufficient for a diagnosis of TTP.
Clinical features of TTP are varied and may include gastrointestinal symptoms (abdominal pain, nausea, vomiting), fatigue, malaise, neurologic abnormalities (altered mental status, confusion, headache), and purpuric rash.
TTP is more common in women and in Americans of African descent. Hereditary TTP usually presents before age 5. Acquired TTP typically presents between the ages of 30 and 50.
M31.1 – Thrombotic microangiopathy
78129009 – Thrombotic thrombocytopenic purpura
- Shiga toxin-mediated TMA (hemolytic-uremic syndrome) – diarrheal illness as prodrome; severe renal dysfunction
- Drug-mediated TMA (quinine, quetiapine, gemcitabine, and calcineurin inhibitors, among others)
- Complement-mediated TMA
- Disseminated intravascular coagulation (DIC)
- Systemic lupus erythematosus
- Systemic sclerosis
- Antiphospholipid antibody syndrome
- Systemic infection (eg, cytomegalovirus, herpes simplex virus, meningococcus)
- Idiopathic thrombocytopenic purpura (ITP)
Last Updated: 06/21/2017