Secondary Thrombotic Thrombocytopenic Purpura (TTP) Triggers and Management

Pathophysiological Mechanisms

Infections, particularly with cytomegalovirus, Helicobacter pylori, hepatitis C, HIV, and varicella zoster, can trigger secondary TTP through immune system activation 1, 2
Pregnancy is a known trigger for TTP, likely due to the physiological decrease in ADAMTS13 activity during pregnancy combined with increased VWF levels 1
Certain drugs can induce TTP through immune-mediated mechanisms or direct toxicity to endothelial cells 1, 3
Common culprit medications include quinine, ticlopidine, clopidogrel, chemotherapeutic agents, and immunosuppressants 2

HIV infection is strongly associated with secondary TTP, with a recommended approach of treating the underlying HIV infection first 3
HIV may induce TTP through direct viral damage to endothelial cells 4
SLE is a common autoimmune cause of secondary TTP 1, 3
The autoimmune dysregulation in SLE can lead to production of autoantibodies against ADAMTS13 2

Evaluation of peripheral blood smear is crucial to identify schistocytes and rule out other causes of thrombocytopenia 2
Screening for underlying conditions should include HIV and hepatitis C testing in all adult patients 4
Helicobacter pylori testing in appropriate cases 2
Autoimmune markers including antinuclear antibodies 2

For secondary forms of TTP, treating the underlying condition is crucial, such as antiviral therapy for HIV-associated TTP 3
Eradication therapy for H. pylori-associated TTP 7
Discontinuation of offending medications 2