What is the management approach for Immune Thrombocytopenic Purpura (ITP)?

Management of Immune Thrombocytopenic Purpura (ITP)

Corticosteroids are the standard first-line treatment for ITP, with short courses (≤6 weeks including taper) strongly preferred over prolonged therapy, followed by splenectomy for steroid-refractory cases, and thrombopoietin receptor agonists for patients who fail splenectomy or have contraindications to surgery. 1

Initial Assessment and Treatment Indications

• Treatment is indicated when platelet count is <30 × 10⁹/L with bleeding risk, not to normalize platelet counts 1
• Treatment is rarely needed if platelet count >50 × 10⁹/L unless the patient has active bleeding, requires surgery, has comorbidities predisposing to bleeding, or needs anticoagulation 2
• Target platelet count should be 30-50 × 10⁹/L to reduce bleeding risk, not to achieve normal counts 2
• Screen for secondary causes including H. pylori (urea breath test, stool antigen, or endoscopic biopsy), HIV, HCV, antiphospholipid syndrome, and lymphoproliferative disorders 1

First-Line Treatment Options

Corticosteroid Regimens

Prednisone 0.5-2 mg/kg/day produces initial response in 70-80% of patients and remains the most commonly recommended first-line therapy 2

• High-dose dexamethasone 40 mg/day for 4 days offers superior response rates (up to 90% initial, 50-80% sustained) compared to conventional prednisone 2
• Dexamethasone can be repeated every 2-4 weeks for 1-4 cycles, with 4 cycles every 14 days producing 86% response rate and 74% sustained responses lasting median 8 months 2
• Rapidly taper and discontinue prednisone after achieving target platelet count in responders 2
• Time to response ranges from several days to several weeks 2

Alternative First-Line Agents

• IVIg 1 g/kg as one-time dose should be used with corticosteroids when rapid platelet increase is required (within 24 hours), or as monotherapy if corticosteroids are contraindicated 1, 3
• IVIg dose may be repeated if necessary 1
• Anti-D immunoglobulin (50-75 μg/kg) can be used in Rh(D)-positive, non-splenectomized patients as first-line if corticosteroids are contraindicated 1, 2

Common Pitfalls with Corticosteroids

• Avoid prolonged corticosteroid courses beyond 6 weeks due to significant morbidities including mood swings, weight gain, insomnia, Cushingoid features, diabetes, fluid retention, osteoporosis, hypertension, avascular necrosis, and immunosuppression 2
• Monitor closely for these complications, particularly with repeated dosing where tolerability decreases 2

Second-Line Treatment for Steroid-Refractory ITP

Splenectomy

Splenectomy is recommended for patients who have failed corticosteroid therapy, offering 80% initial response rate and 66% sustained response for at least 5 years 1, 3

• Both laparoscopic and open splenectomy offer similar efficacy for medically suitable patients 1
• Vaccinate against encapsulated organisms prior to splenectomy 1
• Do not treat asymptomatic patients after splenectomy who have platelet counts >30 × 10⁹/L 1

Thrombopoietin Receptor Agonists (TPO-RAs)

TPO-RAs are recommended for patients at risk of bleeding who relapse after splenectomy or have contraindications to splenectomy and have failed at least one other therapy 1

• Romiplostim (initial dose 1 mcg/kg weekly subcutaneously) demonstrated 61% durable response in non-splenectomized patients and 38% in splenectomized patients 4
• TPO-RAs may be considered for patients at bleeding risk who failed one line of therapy (corticosteroids or IVIg) without prior splenectomy 1
• Monitor for bone marrow reticulin formation during TPO-RA therapy 3, 4
• Risk of thrombosis increases if platelet count becomes excessively high during treatment 4

Rituximab

• Rituximab may be considered for patients at bleeding risk who failed one line of therapy such as corticosteroids, IVIg, or splenectomy, with approximately 60% response rate 1, 3

Special Populations

Pregnancy

• Pregnant patients requiring treatment should receive either corticosteroids or IVIg 1
• Mode of delivery should be based on obstetric indications, not platelet count 1

Secondary ITP

HIV-associated ITP: Treat HIV infection with antiviral therapy before other ITP treatments unless clinically significant bleeding complications exist 1

HCV-associated ITP: Consider antiviral therapy in absence of contraindications, but monitor platelet count closely as interferon may worsen thrombocytopenia; if ITP treatment required, use IVIg as initial therapy 1

H. pylori-associated ITP: Administer eradication therapy in patients with confirmed H. pylori infection (based on urea breath test, stool antigen, or endoscopic biopsy) 1

Patients on Anti-Platelet Therapy

• Target higher platelet threshold (>50 × 10⁹/L) to compensate for increased bleeding risk 3
• Consider combination therapy with corticosteroids and IVIg for patients who cannot discontinue anti-platelet agents 3
• Temporarily discontinue anti-platelet agents if possible while treating ITP 3