Thrombotic thrombocytopenic purpura (TTP)

Thrombotic thrombocytopenic purpura is a rare and serious condition in which small clots form throughout the small blood vessels of the body, using up platelets and damaging red blood cells as they pass through narrowed vessels. The acquired, immune-mediated form is driven by autoantibodies against ADAMTS13, an enzyme that normally helps regulate a clotting protein called von Willebrand factor, leaving that regulation severely impaired.

Research describes an incidence for the immune-mediated form of roughly 1.8 to 4 cases per million people per year, making it one of the rarer conditions in this category. Because clots can form quickly and affect organs including the brain and kidneys, TTP is treated as a medical emergency requiring urgent, specialist-led care rather than a condition to monitor and wait on.

Common signs

Easy bruising and petechiae, fatigue and pale or yellowish skin from anemia, fever, confusion, headache or other neurological changes, and reduced urine output. Because symptoms can come on quickly and severely, prompt specialist care matters.

This is a plain-language summary for orientation, not a diagnosis. Mechanisms are described as current understanding, not settled fact. Work with your own clinician for your care.