From the Guidelines
The additional workup for thrombocytopenia beyond HIV and hepatitis C testing should include a complete blood count with peripheral smear, and a thorough physical examination and medical history to identify any atypical findings that may suggest other etiologies. According to the American Society of Hematology 2011 evidence-based practice guideline for immune thrombocytopenia 1, physical examination, and review of the complete blood count and peripheral blood smear remain the key components of the diagnosis of ITP. Some key points to consider in the workup include:
- A thorough medication review to identify any potential causes of thrombocytopenia
- Checking for abnormalities such as fever or bone or joint pain, a family history of low platelets or easy bruising, risk factors for HIV infection, skeletal or soft-tissue morphologic abnormalities, non-petechial rash, lymphadenopathy or an abnormal hemoglobin level, white blood cell count, or white cell morphology
- Bone marrow evaluation may be necessary if abnormalities in other cell lines are present or if there is concern for aplastic anemia 1
- Testing for other infections such as Helicobacter pylori may also be warranted 1 It is essential to note that the utility of screening all ITP patients for common variable immune deficiency (CVID) is unclear 1, and therefore, it should not be routinely performed. Additionally, bone marrow aspiration and biopsy may be necessary if peripheral destruction is not evident or if there are abnormalities in other cell lines 1. A comprehensive approach to the workup of thrombocytopenia is crucial to distinguish between decreased production, increased destruction, or sequestration as the underlying mechanism, which guides appropriate treatment strategies.
From the Research
Additional Workup for Thrombocytopenia
The workup for thrombocytopenia involves a range of tests to determine the underlying cause of the condition. Some of the additional workup for thrombocytopenia includes:
- Complete blood count (CBC) and peripheral smear review to assess platelet count and morphology 2
- Bone marrow examination to evaluate bone marrow platelet production 2
- Tests to distinguish acute from chronic thrombocytopenia, such as obtaining or reviewing previous platelet counts 3
- Exclusion of pseudothrombocytopenia by collecting blood in a tube containing heparin or sodium citrate and repeating the platelet count 3
- Evaluation for underlying conditions such as hepatic disease, immune thrombocytopenia, and drug-induced thrombocytopenia 3
Specific Tests for Underlying Conditions
Some specific tests that may be ordered as part of the workup for thrombocytopenia include:
- Hepatitis C virus (HCV) testing to evaluate for HCV-related thrombocytopenia 4, 5
- HIV testing to evaluate for HIV-related thrombocytopenia 6
- Tests for autoimmune disorders, such as antiphospholipid syndrome, to evaluate for immune-mediated thrombocytopenia 3
- Tests for thrombotic microangiopathies, such as hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome, to evaluate for thrombotic microangiopathy-related thrombocytopenia 3
Approach to Thrombocytopenia
The approach to thrombocytopenia depends on the clinical presentation and severity of the condition. In general, the approach involves:
- Initial evaluation with CBC and peripheral smear review to assess platelet count and morphology 2
- Further testing to determine the underlying cause of thrombocytopenia, such as bone marrow examination or tests for underlying conditions 2, 3
- Treatment of underlying conditions, such as hepatic disease or immune thrombocytopenia, to manage thrombocytopenia 3, 4, 5