26451 B-Cell Lymphoblastic Leukemia Monitoring, Minimal Residual Disease Detection, Flow Cytometry, Varies (BALLM)

​Acute Minimal Residual Disease, ALL-MRD, B-ALL MRD, B-cell ALL MRD

​Aids in monitoring a previously confirmed diagnosis of B-cell lymphoblastic leukemia

**A copy of the diagnostic flow cytometry report is required.**​

Specimens must be received within 72 hours of collection.

Slides:  If possible, include 5 to 10 unstained bone marrow aspirate or blood smears labeled with 2 unique identifiers.

Collection Instructions:

1. Submission of bilateral specimens is not required.

2. Label specimen appropriately; bone marrow or whole blood.

3. Send specimens in original tube.  Do not aliquot.

​This test is only appropriate for patients who have a previous confirmed diagnosis of B-cell lymphoblastic leukemia. Treatment with antibodies to CD19 may interfere with the ability to detect minimal residual disease (MRD).

​B-cell lymphoblastic leukemia/lymphoma (B-ALL) is a neoplasm of precursor cells (lymphoblasts) committed to B-cell lineage. B-ALL is the most common acute leukemia in children and adolescents and also occurs in adults. Patients with B-ALL typically present with a high blast count in the peripheral blood and bone marrow replacement with the disease. The diagnosis of B-ALL is based on a combination of morphologic features showing primarily small blasts with open chromatin and high N:C ratio, and an immunophenotype showing immaturity (CD34 and/or TdT expression) associated with B-cell lineage markers (CD19, CD22, and CD79a).

New therapeutic approaches in B-ALL have been increasingly successful. One of the most important predictors of the disease relapse is the ability to detect minimal residual disease (MRD) in the bone marrow specimens following induction phase of the therapy (day 28). Immunophenotyping studies are necessary as morphologic features are not sufficient to detect MRD. The absence of MRD (at 0.002% sensitivity) is an important prognostic indicator in these patients.

This test may also be used to establish an immunophenotypic fingerprint of tumor cells at diagnosis to monitor MRD in these patients after treatments or allogeneic stem cell transplant.

​An interpretive report for the presence or absence of B-cell lymphoblastic leukemia (B-ALL) minimal residual disease (MRD) is provided. Patients who have detectable MRD by this assay are considered to have residual/recurrent B-ALL.