What is the treatment for immune thrombocytopenia (ITP)?

Treatment of Immune Thrombocytopenia (ITP)

For adults with newly diagnosed ITP requiring treatment, initiate corticosteroids as first-line therapy, specifically prednisone 0.5-2 mg/kg daily for 2-4 weeks with rapid taper, or consider IVIg (0.4 g/kg/day for 5 days or 1 g/kg/day for 1-2 days) if a more rapid platelet increase is needed. 1

When to Treat

Treatment is not indicated for all patients with ITP. The decision to treat depends on bleeding risk, not just platelet count:

• Observation alone is appropriate for patients with no bleeding or only mild bleeding (skin manifestations like bruising and petechiae), regardless of platelet count 1
• Treatment is generally indicated when platelet counts fall below 20-30 × 10⁹/L with bleeding symptoms, or when bleeding risk is elevated due to comorbidities, planned procedures, or lifestyle factors 1
• Treatment should never aim to normalize platelet counts; the goal is achieving platelet counts ≥50 × 10⁹/L to reduce bleeding risk 1, 2, 3

Critical pitfall: Treatment-related mortality can exceed bleeding-related mortality in patients with platelet counts >30 × 10⁹/L without active bleeding 1

Diagnosis

ITP is a diagnosis of exclusion defined as platelet count <100 × 10⁹/L without other identifiable causes 1:

• Bone marrow examination is not necessary in patients presenting with typical ITP features, regardless of age 1
• Essential testing: Complete blood count, peripheral blood smear evaluation, HIV and HCV screening 1
• Exclude secondary causes including: H. pylori infection, hepatitis C, HIV, antiphospholipid syndrome, systemic lupus erythematosus, lymphoproliferative disorders, and drug-induced thrombocytopenia 1

First-Line Treatment Options

Corticosteroids (Preferred)

Prednisone 0.5-2 mg/kg daily for 2-4 weeks achieves 70-80% initial response rates 1. Longer courses (21 days with taper) provide more durable responses compared to short courses 1

Dexamethasone 40 mg daily for 4 days produces up to 90% initial response with 50-80% sustained response rates, though this requires validation in randomized trials 1

Key consideration: Corticosteroid adverse effects (weight gain, mood changes, diabetes, hypertension, osteoporosis, immunosuppression) rapidly accumulate and often outweigh benefits with prolonged use 1

Intravenous Immunoglobulin (IVIg)

• Dosing: 0.4 g/kg/day for 5 days OR 1 g/kg/day for 1-2 days 1
• Achieves up to 80% response rate with rapid onset (24 hours to several days) 1
• Use when rapid platelet increase is required (active bleeding, urgent procedures) 1
• Responses typically last 3-4 weeks 1

Anti-D Immunoglobulin

• Dosing: 50-75 μg/kg for Rh-positive, non-splenectomized patients 1
• Contraindicated in patients with decreased hemoglobin from bleeding or autoimmune hemolysis 1
• Response rates similar to IVIg but with risk of hemolytic anemia 1

Second-Line Treatment for Corticosteroid Failure

Splenectomy

Splenectomy is recommended for patients who fail corticosteroid therapy and have persistent bleeding or quality of life impairment 1. It provides the highest rate of sustained remission off all treatments (>60% long-term response) 1:

• Delay splenectomy for at least 12 months unless severe bleeding unresponsive to other measures 1
• Laparoscopic and open approaches offer similar efficacy 1
• No further treatment needed post-splenectomy if platelet counts >30 × 10⁹/L without bleeding 1

Thrombopoietin Receptor Agonists (TPO-RAs)

Strongly recommended for patients at bleeding risk who relapse after splenectomy or have contraindications to splenectomy after failing at least one other therapy 1:

• Romiplostim (Nplate): Initial dose 1 mcg/kg subcutaneously weekly, titrate by 1 mcg/kg increments to achieve platelets ≥50 × 10⁹/L (maximum 10 mcg/kg weekly) 2
• Eltrombopag (Promacta/ALVAIZ): Initial dose 36 mg orally daily (18 mg for East/Southeast Asian ancestry or hepatic impairment), titrate to achieve platelets ≥50 × 10⁹/L 3

TPO-RAs may be considered before splenectomy in patients who have failed one line of therapy, though evidence is weaker 1

Rituximab

• May be considered for patients at bleeding risk who have failed corticosteroids, IVIg, or splenectomy 1
• Pooled response rate: 62.5% overall, but only 18-35% maintain response beyond 1 year 1
• Risk of severe complications including progressive multifocal leukoencephalopathy (rare in ITP) 1

Special Populations

Pregnancy

• Corticosteroids or IVIg are recommended for pregnant patients requiring treatment 1
• Mode of delivery should be based on obstetric indications, not maternal platelet count 1

Secondary ITP

HIV-associated: Treat underlying HIV infection with antiretroviral therapy before other ITP treatments unless clinically significant bleeding present 1

HCV-associated: Consider antiviral therapy; if ITP treatment needed, use IVIg as initial therapy 1

H. pylori-associated: Eradication therapy is recommended for all patients testing positive (urea breath test, stool antigen, or endoscopic biopsy) 1

Monitoring

• Weekly complete blood counts during dose adjustment phase 2
• Monthly monitoring once stable dose established 2
• Weekly for 2 weeks after discontinuation of therapy 2

Critical Pitfalls to Avoid

• Never use TPO-RAs in myelodysplastic syndrome (MDS) - they are contraindicated and may increase blast transformation risk 2, 3, 2
• Avoid anti-D in patients with pre-existing anemia or autoimmune hemolysis 1
• Do not continue ineffective therapy beyond 4 weeks at maximum dose 2
• Recognize that refractory thrombocytopenia may represent MDS with isolated thrombocytopenia rather than true ITP - requires bone marrow examination with cytogenetics 4