Bone Marrow Collection Tubes for Pediatric Persistent ITP
Bone marrow aspirate and trephine (BMAT) should not be performed in children with persistent ITP who have typical clinical features, making the question of which tubes to use clinically irrelevant in this scenario. 1
Why BMAT is Not Indicated
The American Society of Hematology 2011 guidelines provide clear, strong recommendations against bone marrow examination in pediatric ITP:
- Grade 1B recommendation: Bone marrow examination is unnecessary in children and adolescents with typical features of ITP 1
- Grade 1B recommendation: Bone marrow examination is not necessary in children who fail IVIg therapy 1
- Grade 2C recommendation: Bone marrow examination is not necessary prior to corticosteroid treatment or before splenectomy 1
When BMAT Might Be Considered
Bone marrow examination should only be pursued if there are atypical features suggesting an alternative diagnosis:
- Abnormalities in the blood count beyond isolated thrombocytopenia (e.g., anemia not explained by bleeding, leukopenia, or leukocytosis) 1
- Abnormal findings on peripheral blood smear (blasts, dysplastic cells) 1
- Lack of response to standard ITP therapies combined with concerning clinical features suggesting malignancy or bone marrow failure
If BMAT is Performed (Atypical Cases)
When bone marrow examination is genuinely indicated due to atypical features, standard collection protocols apply 2:
- EDTA tubes for bone marrow aspirate (for morphology, flow cytometry)
- Heparin tubes for cytogenetic studies
- Sterile containers for culture if infection suspected
- Slides prepared at bedside for optimal morphologic assessment
The ICSH guidelines emphasize that aspirate and trephine biopsy specimens are complementary and should both be obtained when bone marrow examination is performed 2.
Clinical Caveat
The persistent nature of ITP (lasting 3-12 months) does not change the recommendation against routine bone marrow examination. The diagnosis remains clinical, based on isolated thrombocytopenia without other cytopenias or blood smear abnormalities 1, 3.