From the Guidelines
The approach to thrombocytopenia should begin with a thorough history and physical examination, followed by initial laboratory testing including complete blood count with differential, peripheral smear review, and reticulocyte count, as recommended by the most recent guidelines 1. The initial step in evaluating thrombocytopenia is to confirm the low platelet count with a peripheral blood smear to rule out pseudothrombocytopenia.
- A thorough history should focus on:
- Medication use
- Recent infections
- Alcohol consumption
- Liver disease
- Pregnancy status
- Family history of autoimmunity or personal history of autoimmune diseases
- Physical examination should evaluate for signs of bleeding, lymphadenopathy, hepatosplenomegaly, and other systemic conditions. Initial laboratory testing includes:
- Complete blood count with differential
- Peripheral smear review
- Reticulocyte count
- Consider testing for HIV, HCV, HBV, and H. pylori in patients with newly diagnosed immune thrombocytopenia (ITP) 1. Bone marrow evaluation should only be considered if abnormalities are found in the initial testing results and further investigation is necessary for a diagnosis 1. Management depends on the cause, platelet count, and bleeding risk.
- For ITP, treatment is indicated for counts below 30,000/μL or if bleeding is present, typically with corticosteroids (prednisone 1 mg/kg/day for 2-4 weeks) as first-line therapy, followed by IVIG (1 g/kg for 1-2 days) if rapid response is needed, as suggested by the guidelines for management of immune-related adverse events 1.
From the FDA Drug Label
Nplate is indicated for the treatment of thrombocytopenia in: Adult patients with immune thrombocytopenia (ITP) who have had an insufficient response to corticosteroids, immunoglobulins, or splenectomy Nplate should be used only in patients with ITP whose degree of thrombocytopenia and clinical condition increases the risk for bleeding.
The approach to work up thrombocytopenia is not directly addressed in the provided drug label. The FDA drug label does not answer the question.
From the Research
Approach to Thrombocytopenia
The approach to thrombocytopenia involves a systematic evaluation to identify the underlying cause and determine the severity of the condition.
- Examination of the blood film is essential in the investigation of any patient with thrombocytopenia 2.
- The context in which thrombocytopenia occurred, its severity, timing, and association with bleeding are important clues to the diagnosis 2.
- Initial decision-making relies on a good history and the results of some simple investigations 3.
Evaluation of Thrombocytopenia
The evaluation of thrombocytopenia includes:
- Excluding pseudothrombocytopenia by collecting blood in a tube containing heparin or sodium citrate and repeating the platelet count 4.
- Distinguishing acute from chronic thrombocytopenia by obtaining or reviewing previous platelet counts 4.
- Identifying the underlying cause of thrombocytopenia, which can be due to decreased platelet production, increased destruction, splenic sequestration, or dilution or clumping 4.
Management of Thrombocytopenia
The management of thrombocytopenia depends on the underlying cause and severity of the condition.
- Transfusion of platelets is recommended when patients have active hemorrhage or when platelet counts are less than 10 × 10^3 per μL, in addition to treatment (when possible) of underlying causative conditions 4.
- Patients with platelet counts of less than 50 × 10^3 per μL should adhere to activity restrictions to avoid trauma-associated bleeding 4.
- In patients with immune thrombocytopenia (ITP), treatment with corticosteroids, intravenous immune globulin (IVIG), and platelet transfusions may be necessary in cases of critical hemorrhage 5.