What is the diagnosis and treatment for Immune Thrombocytopenic Purpura (ITP)?

From the Guidelines

Immune thrombocytopenia (ITP) should be treated with either prednisone (0.5-2.0 mg/kg per day) or dexamethasone (40 mg per day for 4 days) as the initial therapy, with a preference for dexamethasone if a rapid platelet count response is desired. The diagnosis of ITP is based on low platelet counts due to immune-mediated platelet destruction and impaired platelet production.

First-line Treatment

• Corticosteroids such as prednisone or dexamethasone are the first-line treatment for adults with ITP, as recommended by the American Society of Hematology 2019 guidelines 1.
• For patients requiring a rapid platelet increase, intravenous immunoglobulin (IVIG) at 1 g/kg for 1-2 days can be added to the treatment regimen.

Second-line Treatment

• Second-line options include thrombopoietin receptor agonists (TPO-RAs) like eltrombopag (50-75 mg daily) or romiplostim (1-10 μg/kg weekly), which have been shown to be highly effective in clinical trials with response rates of 70-80% 1.
• Rituximab (375 mg/m² weekly for 4 weeks) is another second-line option, which has been demonstrated to trigger short-term responses in 50-60% of patients, with long-term responses documented in 20-30% of cases 1.
• Splenectomy is also a second-line option, particularly for refractory cases, with an initial response rate of 85% and durable responses in about 60-65% of patients 1.

Treatment Indication and Monitoring

• Treatment is generally indicated for platelet counts below 30,000/μL or if bleeding symptoms are present.
• Patients should be monitored for bleeding symptoms, medication side effects, and regular platelet count checks to assess treatment response. The pathophysiology of ITP involves autoantibodies targeting platelet glycoproteins, leading to premature destruction by the reticuloendothelial system, particularly in the spleen.

Quality of Life

• The introduction of TPO-RAs has a positive impact on the quality of life of ITP patients, with significant reductions in bleeding events and emergency hospitalizations 1.

From the FDA Drug Label

Nplate is a prescription medicine used to treat low blood platelet counts (thrombocytopenia) in: adults with immune thrombocytopenia (ITP) when certain medicines or surgery to remove your spleen have not worked well enough children 1 year of age and older with ITP for at least 6 months when certain medicines or surgery to remove your spleen have not worked well enough.

The diagnosis of Immune Thrombocytopenic Purpura (ITP) is not explicitly stated in the label, but it is implied that a diagnosis of ITP is necessary for treatment with Nplate. The treatment for ITP with Nplate involves subcutaneous injections once a week, with dose adjustments based on platelet counts. The goal of treatment is to maintain a platelet count of at least 50,000 per microliter to lower the risk of bleeding. 2

From the Research

Diagnosis of Immune Thrombocytopenic Purpura (ITP)

• ITP is diagnosed by exclusion of possible underlying causes of thrombocytopenia 3
• The diagnosis consists of simple diagnostic procedures to rule out other conditions that may cause thrombocytopenia 3
• Platelet count is a key factor in diagnosing ITP, with a count lower than 100 x 10(9)/L indicating the condition 3

Treatment of ITP

• The decision to treat ITP should be based on individual factors, including platelet count, bleeding risk factors, and patient preference 3
• First-line treatment for ITP typically includes corticosteroids, such as prednisone or dexamethasone 4, 3, 5
• High-dose dexamethasone (HDD) has been shown to be effective as a first-line treatment, with a rapid response and comparable long-term prognosis to conventional prednisone treatment 4, 5
• Other first-line treatment options include intravenous immunoglobulin (IVIG) and anti-D immunoglobulin, which can provide a rapid increase in platelet count 6, 3
• Second-line treatment options include thrombopoietin receptor agonists, such as eltrombopag, and rituximab, which can be used in patients who do not respond to first-line treatment 7, 3
• Splenectomy is also a treatment option for patients with ITP, particularly those who do not respond to other treatments, but it is typically reserved for patients with significant symptoms or bleeding complications 6, 3

Response to Treatment

• The response to treatment can vary depending on the individual and the treatment used 4, 5
• Some patients may experience a rapid response to treatment, while others may take longer to respond 5
• The sustained response to treatment can also vary, with some patients experiencing a longer duration of response than others 5
• Adverse events can occur with treatment, and the frequency and severity of these events can vary depending on the treatment used 5