There are no official guidelines to assist in answering this question. I will search for relevant research papers instead.
From the Research
Differences between TTP and ITP
- Thrombotic Thrombocytopenic Purpura (TTP) is a rare but life-threatening hematological disorder characterized by microangiopathic hemolytic anemia, severe thrombocytopenia, and ischemic end-organ injury due to microvascular platelet-rich thrombi 1.
- Immune Thrombocytopenic Purpura (ITP) is an organ-specific autoimmune disease in which the platelets and their precursors become targets of a dysfunctional immune system, leading to a decrease in platelet number and a bleeding disorder 2.
- The pathophysiology of TTP is based on a severe ADAMTS13 deficiency, while ITP is caused by an autoimmune response involving both the innate and adaptive immune systems 1, 2.
- TTP patients have a significantly shorter mean red blood cell lifespan (RBCLS) compared to patients with ITP accompanied by anemia, which can be used as a diagnostic tool to differentiate between the two diseases 3.
Diagnostic Criteria
- TTP is characterized by microangiopathic hemolytic anemia, thrombocytopenia, and ischemic end-organ injury, while ITP is characterized by a low platelet count and a bleeding disorder 1, 2.
- The diagnostic accuracy of RBCLS in predicting TTP can reach 93% by excluding the impact of gastrointestinal bleeding, with an optimal cut-off value of 32 days 3.
- Monitoring of ADAMTS13 activity is important to identify cases with a low value of activity, requiring the optimization of immunosuppressive therapy 4.
Treatment Options
- Front-line therapy for TTP includes daily plasma exchange with fresh frozen plasma replacement and immunosuppression with corticosteroids, while caplacizumab has recently been added to frontline therapy 1, 4.
- ITP treatment involves immunosuppression and antiaggregant or anticoagulant therapy to prevent thrombotic events 2.
- Rituximab is effective in patients with refractory or relapsing TTP, and its use has expanded to frontline treatment and as a pre-emptive approach during follow-up 4.