From the Guidelines
Immune thrombocytopenic purpura (ITP), thrombotic thrombocytopenic purpura (TTP), and hemolytic uremic syndrome (HUS) are distinct hematologic disorders with different clinical presentations and treatments, and the most recent evidence suggests that ITP treatment should prioritize corticosteroids and thrombopoietin receptor agonists to minimize morbidity and mortality 1.
Clinical Presentation
- ITP is characterized by isolated thrombocytopenia due to immune-mediated platelet destruction, presenting with mucocutaneous bleeding but normal coagulation studies.
- TTP features the pentad of thrombocytopenia, microangiopathic hemolytic anemia, neurological symptoms, renal dysfunction, and fever, caused by ADAMTS13 deficiency leading to microvascular thrombosis.
- HUS presents with the triad of thrombocytopenia, microangiopathic hemolytic anemia, and acute kidney injury, typically following Shiga toxin-producing E. coli infection in typical HUS, while atypical HUS involves complement dysregulation.
Treatment
- ITP treatment should start with corticosteroids (prednisone 1-2 mg/kg/day for 2-4 weeks) and may include intravenous immunoglobulin (IVIG 1 g/kg for 1-2 days) and thrombopoietin receptor agonists like eltrombopag or rituximab in chronic cases 1.
- TTP requires immediate plasma exchange (1-1.5 plasma volumes daily until platelet normalization), often with corticosteroids and rituximab.
- HUS treatment is supportive care with fluid management and dialysis if needed for typical HUS, while atypical HUS requires complement inhibitors like eculizumab.
Key Distinctions
- ITP shows isolated thrombocytopenia without microangiopathy.
- TTP and HUS both feature microangiopathic hemolytic anemia but differ in their predominant organ involvement (neurological in TTP versus renal in HUS) and underlying pathophysiology.
- The choice of treatment should prioritize minimizing morbidity and mortality, and the most recent evidence suggests that corticosteroids and thrombopoietin receptor agonists are the most effective treatments for ITP 1.
From the Research
Clinical Differences
- ITP (Immune Thrombocytopenic Purpura) is characterized by immunologically mediated destruction of platelets, whereas TRP (Thrombocytopenia) is a broader term that encompasses various conditions leading to low platelet count 2, 3.
- HUS (Hemolytic Uremic Syndrome) is a condition characterized by hemolytic anemia, acute kidney injury, and low platelet count, often caused by bacterial infections or other factors 2, 3.
- The clinical presentation of ITP, TRP, and HUS differs in terms of underlying causes, symptoms, and treatment approaches.
Treatment Approaches
- ITP treatment typically involves corticosteroids as first-line therapy, with the goal of increasing platelet count and reducing bleeding risk 2, 3, 4, 5.
- Intravenous immunoglobulin (IVIg), anti-D immunoglobulin, and splenectomy are also used in the management of ITP, particularly in cases of refractory or severe disease 3, 4, 5.
- Plasma exchange has been used in some cases of severe ITP, particularly those resistant to steroid therapy 6.
- Treatment of TRP and HUS depends on the underlying cause and may involve supportive care, antibiotics, or other specific therapies.
- Thrombopoietin receptor agonists are being investigated as a potential treatment option for ITP, but their efficacy and safety are still being evaluated 5.
Comparison of Treatment Options
- Corticosteroids, such as prednisone and dexamethasone, are commonly used in the treatment of ITP, with dexamethasone potentially offering a faster increase in platelet count and reduced adverse events 2.
- Rituximab, an anti-CD20 antibody, has been shown to induce sustained remissions in some patients with chronic ITP, particularly when used in combination with dexamethasone 2, 4.
- Splenectomy is a potentially curative option for ITP, but it is an invasive procedure with associated risks and is typically reserved for patients who do not respond to medical therapy 3, 5.