Q. Is there a relationship between hemolytic-uremic syndrome and thrombotic thrombocytopenic purpura? I see them lumped together a lot. Also, what does it mean to treat an HUS patient supportively?

A. Yes, there is a relationship between HUS and TTP. In both disorders, there is widespread small vessel thrombosis. Some of the symptoms of HUS and TTP are overlapping (both have microangiopathic hemolytic anemia – as seen above – and thrombocytopenia), and although HUS tends to involve more kidney/gut and TTP tends to be more systemic and have CNS symptoms, sometimes it can be hard to tell the two apart. Though the mechanisms are now known to be entirely different (HUS usually occurs in association with E. coli infection; TTP is due to a lack of ADAMTS13), because of the clinical similarities, they are lumped together under the heading “thrombotic microangiopathies.” Take a look at this case to see how all this fits together in real life.

Supportive treatment of any disease – including HUS – generally means treatment that is aimed to relieve symptoms and maintain homeostasis (as opposed to treatment that is aimed at curing the disease itself). It often includes close monitoring of cardiovascular status (blood pressure and heart rate) and electrolytes. If blood pressure drops or heart function is diminished, you can give fluids and/or drugs to stimulate heart function. Electrolytes are generally managed by the addition of sodium and/or potassium to fluids. Supportive treatment may also include pain management, and other measures aimed at making the patient more comfortable.