Most common clinical syndromes associated with thrombotic microangiopathy

What are the most common clinical syndromes associated with thrombotic microangiopathy?

• Shiga toxin–associated hemolytic uremia syndrome (ST-HUS)

• Thrombotic thrombocytopenic purpura (TTP)

• Atypical hemolytic uremic syndrome (aHUS)

Are there clinical features that may help distinguish between these clinical syndromes?

Yes and no. HUS often presents with kidney injury, whereas TTP is associated with more neurologic dysfunction and less often kidney injury. Although these associations are “classic,” patients with TTP can have kidney injury and patients with HUS can have neurologic manifestations. The platelet count in aHUS as compared with TTP is rarely less than 80,000. The classic clinical pentad of TTP includes:

• • microangiopathic hemolytic anemia
• • thrombocytopenia
• • acute kidney injury
• • neurologic symptoms
• • fever