What are the diagnostic criteria and treatment options for thrombocytopenia (low platelet count)?

From the Guidelines

Thrombocytopenia is diagnosed when platelet counts fall below 150,000 per microliter of blood, with severity classified as mild (100,000-150,000), moderate (50,000-100,000), or severe (<50,000) 1. Diagnosis requires a complete blood count, peripheral blood smear examination, and investigation of underlying causes such as medications, infections, autoimmune disorders, bone marrow problems, or pregnancy complications.

Key Diagnostic Steps:

• Complete blood count to determine platelet count
• Peripheral blood smear examination to evaluate platelet morphology
• Investigation of underlying causes, including:
  • Medications
  • Infections
  • Autoimmune disorders
  • Bone marrow problems
  • Pregnancy complications Treatment depends on the cause, severity, and bleeding risk.

Treatment Options:

• For mild cases without bleeding, observation may be sufficient
• First-line treatments for immune thrombocytopenia include:
  • Corticosteroids (prednisone 1-2 mg/kg/day for 2-4 weeks followed by tapering) 1
  • Intravenous immunoglobulin (1 g/kg for 1-2 days)
  • Anti-D immunoglobulin in Rh-positive patients
• Second-line options include:
  • Thrombopoietin receptor agonists like eltrombopag (25-75 mg daily) or romiplostim (1-10 μg/kg weekly) 1
  • Rituximab (375 mg/m² weekly for 4 weeks)
  • Immunosuppressants
• Severe or refractory cases may require splenectomy
• Drug-induced thrombocytopenia requires discontinuation of the offending medication
• Platelet transfusions are reserved for severe thrombocytopenia (<10,000) with active bleeding or before procedures 1 Patients should avoid aspirin and NSAIDs, which affect platelet function, and take precautions to prevent injury. Regular monitoring of platelet counts is essential during treatment to assess response and adjust therapy accordingly. In patients with chronic, stable, severe thrombocytopenia who are not receiving active treatment, prophylactic platelet transfusion may not be necessary, and transfusions can be reserved for episodes of hemorrhage or during times of active treatment 1.

From the FDA Drug Label

The median platelet count was 19 × 10^9/L at study entry. A durable platelet response was the achievement of a weekly platelet count ≥ 50 × 10^9/L for any 6 of the last 8 weeks of the 24-week treatment period in the absence of rescue medication at any time.

The diagnostic criteria for thrombocytopenia is a platelet count of ≤ 30 × 10^9/L prior to study entry, and ≤ 50 × 10^9/L for a durable platelet response.

• Key diagnostic criteria:
  • Platelet count
  • Duration of thrombocytopenia
  • Prior treatments
• Treatment options:
  • Nplate (romiplostim)
  • Rescue therapies (i.e., corticosteroids, IVIG, platelet transfusions, and anti-D immunoglobulin)
  • Reduction/Discontinuation of Baseline Concurrent ITP Medical Therapy 2 2

From the Research

Diagnostic Criteria for Thrombocytopenia

• Thrombocytopenia is defined as a platelet count of less than 150 × 10^3 per μL 3, 4, 5
• The condition can occur due to decreased platelet production, increased destruction, splenic sequestration, or dilution or clumping 3
• Patients with a platelet count greater than 50 × 10^3 per μL are generally asymptomatic, while those with counts between 20 and 50 × 10^3 per μL may experience mild skin manifestations such as petechiae, purpura, or ecchymosis 3
• Patients with platelet counts of less than 10 × 10^3 per μL have a high risk of serious bleeding 3

Treatment Options for Thrombocytopenia

• Treatment is based on the etiology of the condition and may involve addressing the underlying cause 3, 4, 5
• Transfusion of platelets is recommended for patients with active hemorrhage or platelet counts less than 10 × 10^3 per μL, in addition to treatment of underlying causative conditions 3
• Patients with platelet counts of less than 50 × 10^3 per μL should adhere to activity restrictions to avoid trauma-associated bleeding 3
• For primary immune thrombocytopenia, corticosteroids are the standard first-line treatment, with intravenous immune globulin (IVIG) or Rho(D) immune globulin used for steroid-resistant cases 6
• Second-line therapy for refractory or non-responsive immune thrombocytopenia includes splenectomy or rituximab, a monoclonal antibody against the CD20 antigen 6

Evaluation and Management of Thrombocytopenia

• A history, physical examination, and laboratory studies can help differentiate patients who require immediate intervention from those who can be treated in the outpatient setting 4
• Consultation with a hematologist should be considered if patients require hospitalization, have evidence of systemic disease, or experience worsening thrombocytopenia despite initial treatment 4
• In intensive care unit patients, thrombocytopenia is common and can influence patient management, prompting physicians to withhold or delay necessary invasive interventions or order prophylactic platelet transfusion 7