What is the initial workup and treatment for a patient with thrombocytopenia (low platelet count)?

Initial Workup and Treatment for Thrombocytopenia

The initial workup for thrombocytopenia should include testing for HCV and HIV, examination of peripheral blood smear, and further investigations only if there are abnormalities other than thrombocytopenia in the blood count. 1, 2

Diagnostic Workup

• Confirm thrombocytopenia by collecting blood in a tube containing heparin or sodium citrate to exclude pseudothrombocytopenia 3
• Review previous platelet counts to distinguish acute from chronic thrombocytopenia 3
• Examine peripheral blood smear to exclude other causes of thrombocytopenia 2
• Test for HCV and HIV in all patients with suspected thrombocytopenia (grade 1B) 1, 2
• A bone marrow examination is not necessary for patients presenting with typical ITP (grade 2C) 1, 2
• Consider liver function tests, especially in patients with risk factors 2
• Screen for H. pylori in patients where eradication therapy would be used if testing is positive (grade 2C) 2
• Consider additional testing based on clinical presentation to identify potential causes:
  • Drug-induced thrombocytopenia
  • Immune thrombocytopenia
  • Hepatic disease
  • Heparin-induced thrombocytopenia
  • Thrombotic microangiopathies 3, 4

Treatment Approach

When to Treat

• Treatment is indicated for patients with:
  • Platelet counts <10,000/μL regardless of bleeding 2, 3
  • Platelet counts <20,000/μL with significant mucous membrane bleeding 2
  • Platelet counts <30,000/μL in newly diagnosed patients (grade 2C) 1

First-Line Treatment for ITP

• For adult patients requiring treatment, use corticosteroids as first-line therapy 1, 2
• Short courses (≤6 weeks) of prednisone are preferred over prolonged courses (>6 weeks) (strong recommendation) 1
• When rapid increase in platelet count is required, use IVIG with corticosteroids (grade 2B) 1, 2
• IVIG should be administered at an initial dose of 1 g/kg as a one-time dose; this dosage may be repeated if necessary (grade 2B) 1, 2
• Anti-D immunoglobulin can be used as first-line treatment in appropriate patients (Rh-positive, non-splenectomized) if corticosteroids are contraindicated (grade 2C) 1, 2

Management of Severe or Life-Threatening Bleeding

• Patients with severe, life-threatening bleeding should receive:
  • High-dose parenteral glucocorticoid therapy 2
  • IVIG 2
  • Platelet transfusions 2, 4
• Hospitalization is appropriate for patients with platelet counts <20,000/μL who have significant mucous membrane bleeding 2, 3

Second-Line Treatment Options

• Splenectomy is recommended for patients who fail corticosteroid therapy (grade 1B) 1, 2
• Thrombopoietin receptor agonists (like romiplostim) may be considered for patients at risk of bleeding who have failed one line of therapy such as corticosteroids or IVIG (grade 2C) 1, 5
• Rituximab may be considered for patients at risk of bleeding who have failed one line of therapy (grade 2C) 1, 2

Management of Secondary Thrombocytopenia

• For HCV-associated ITP:
  • Consider antiviral therapy in the absence of contraindications (grade 2C) 1, 2
  • If ITP treatment is required, initial treatment should be IVIG (grade 2C) 2
• For HIV-associated ITP:
  • Consider antiviral therapy before other treatment options unless clinically significant bleeding is present (grade 1A) 2
  • If ITP treatment is required, initial treatment should consist of corticosteroids, IVIG, or anti-D (grade 2C) 2
• For H. pylori-associated ITP:
  • Administer eradication therapy for patients who test positive (grade 1B) 2

Special Considerations

Activity Restrictions

• Patients with platelet counts <50,000/μL should adhere to activity restrictions to avoid trauma-associated bleeding 3

Monitoring

• Obtain complete blood counts (CBCs), including platelet counts, weekly during the dose adjustment phase of therapy 5
• Continue monitoring platelet counts monthly following establishment of a stable treatment regimen 5
• Monitor for at least 2 weeks following discontinuation of treatment 5

Common Pitfalls and Caveats

• Thrombocytopenia does not protect against thrombosis; antithrombotic therapy is often required despite low platelet counts 4
• As a general rule, antithrombotic therapy should not be withheld because of thrombocytopenia alone 4
• Avoid delaying necessary invasive procedures solely due to mild or moderate thrombocytopenia 6
• Be aware that some conditions can present with both thrombocytopenia and thrombosis (e.g., antiphospholipid syndrome, heparin-induced thrombocytopenia, thrombotic microangiopathies) 3
• Monitor for corticosteroid side effects including hypertension, hyperglycemia, sleep and mood disturbances, gastric irritation, glaucoma, myopathy, and osteoporosis 1