Treatment of Thrombocytopenia
The treatment of thrombocytopenia should be tailored to the underlying cause, with corticosteroids being the standard initial treatment for primary immune thrombocytopenia (ITP), while treatment is rarely indicated for platelet counts above 50 × 10^9/L unless specific risk factors are present. 1, 2
When to Initiate Treatment
- Treatment is rarely indicated in patients with platelet counts above 50 × 10^9/L unless they have bleeding, trauma, surgery, comorbidities predisposing to bleeding, mandated anticoagulation therapy, or professions predisposing to trauma 1, 2
- Observation alone is recommended for patients with no bleeding or only mild skin manifestations, regardless of platelet count 2, 3
- Patients with platelet counts between 20-50 × 10^9/L may have mild skin manifestations such as petechiae, purpura, or ecchymosis 4
- Patients with platelet counts below 10 × 10^9/L have a high risk of serious bleeding and typically require intervention 4
First-Line Treatment Options for ITP
Corticosteroids
- Prednisone is the standard initial therapy at 0.5-2 mg/kg/day until platelet count increases to 30-50 × 10^9/L, typically requiring several days to weeks 1
- To avoid corticosteroid-related complications, prednisone should be rapidly tapered and stopped in responders, and especially in non-responders after 4 weeks 1
- Dexamethasone (40 mg/day for 4 days) has shown high initial response rates with sustained responses in 50-86% of patients 1, 2
- Methylprednisolone administered parenterally has been used in various regimens for patients failing first-line therapies, with 80% response rates 1
Emergency Treatment Options
- Intravenous immunoglobulin (IVIg) at 0.8-1 g/kg is recommended for rapid platelet count elevation in emergency situations 2, 3
- IV anti-D immunoglobulin is appropriate for Rh(D) positive, non-splenectomized ITP patients but should be avoided in those with autoimmune hemolytic anemia 1
Second-Line Treatment Options
Thrombopoietin Receptor Agonists (TPO-RAs)
- Romiplostim is FDA-approved for adult and pediatric ITP patients who have had insufficient response to corticosteroids, immunoglobulins, or splenectomy 5
- The initial dose of romiplostim is 1 mcg/kg administered subcutaneously weekly, with dose adjustments based on platelet count response 5
- TPO-RAs are not immunosuppressive and have high efficacy but may be expensive 2, 6
- Discontinue TPO-RAs if the platelet count does not increase to a level sufficient to avoid clinically important bleeding after 4 weeks at the maximum weekly dose 5
Other Options
- Rituximab (anti-CD20) is commonly used as a second-line option though not FDA-approved specifically for ITP 2, 7
- Splenectomy has high initial response rates (85%) but up to 30% of responders relapse within 10 years 2
- Fostamatinib and immunosuppressive agents are additional options for refractory cases 7
Treatment of Secondary Thrombocytopenia
- For HCV-associated thrombocytopenia, antiviral therapy should be considered if not contraindicated 2
- For HIV-associated thrombocytopenia, antiretroviral therapy can improve cytopenias 2
- For cancer-associated thrombocytopenia with concurrent thrombosis, dose-modified anticoagulation may be considered when platelet counts are below 50 × 10^9/L 1
Common Pitfalls and Considerations
- Long-term corticosteroid use should be avoided due to significant adverse effects 2
- Pseudothrombocytopenia (platelet clumping due to EDTA) should be ruled out by examining peripheral blood smear or collecting blood in tubes containing heparin or sodium citrate 2, 4
- Transfusion of platelets is recommended when patients have active hemorrhage or when platelet counts are less than 10 × 10^3/μL 4
- The goal of treatment is to achieve a platelet count associated with adequate hemostasis rather than a normal platelet count 6
- Thrombocytopenia does not protect against thrombosis, and antithrombotic therapy should not be withheld because of thrombocytopenia alone 8