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Test Catalog

Test ID: BALLM    
B-Cell Lymphoblastic Leukemia Monitoring, Minimal Residual Disease Detection, Flow Cytometry, Bone Marrow

Useful For Suggests clinical disorders or settings where the test may be helpful

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

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

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.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

An interpretive report will be provided.

This test will be processed as a laboratory consultation. An interpretation of the immunophenotypic findings and correlation with the morphologic features will be provided by a hematopathologist for every case.

Interpretation Provides information to assist in interpretation of the test results

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.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

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).

Supportive Data

Sixty seven patient samples were analyzed with 38 of these showing no measurable minimal residual disease (MRD). Three of these had levels greater than 20% ALL involvement. Eleven of these had 0.13% to 10.0% MRD involvement. The 15 with the lowest percent MRD involvement ranged from 0.003% to 0.08%. In addition 25 normal bone marrows showed no MRD.

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Bader P, Kreyenberg H, Henze GH, et al: ALL-REZ BFM Study Group. Prognostic value of minimal residual disease quantification before allogeneic stem-cell transplantation in relapsed childhood acute lymphoblastic leukemia: The ALL-REZ BFM Study Group. J Clin Oncol 2009;27:377-384

2. Borowitz MJ, Devidas M, Hunger SP, et al: Children's Oncology Group. Clinical significance of minimal residual disease in childhood acute lymphoblastic leukemia and its relationship to other prognostic factors: A Children's Oncology Group study. Blood 2008;111:5477-5485

3. Borowitz MJ, Pullen DJ, Winick N, et al: Comparison of diagnostic and relapse flow cytometry phenotypes in childhood acute lymphoblastic leukemia: implications for residual disease detection: a report from the children's oncology group. Cytometry B Clin Cytom 2005;68:18-24

4. Campana D: Role of minimal residual disease monitoring in adult and pediatric acute lymphoblastic leukemia. Hematol Oncol Clin North Am 2009;23:1083-1098

5. Chen W, Karadikar NJ, McKenna RW, Kroft SH: Stability of leukemia-associated immunophenoypes in precursor B-lymphoblastic leukemia/lymphoma. a single institution experience. Am J Clin Pathol 2007;127:39-46

6. Coustan-Smith E, Ribeiro RC, Stow P, et al: A simplified flow cytometric assay identifies children with acute lymphoblastic leukemia who have a superior clinical outcome. Blood 2006;108:97-102

7. Coustan-Smith E, Sancho J, Behm FG, et al: Prognostic importance of measuring early clearance of leukemic cells by flow cytometry in childhood acute lymphoblastic leukemia. Blood 2002;100:52-58

8. Guillaume N, Penther D, Vaida I, et al: CD66c expression in B-cell lymphoblastic leukemia: strength and weakness. Int J Lab Hematol 2011;33:92-96

9. Stow P, Key L, Chen X, et al: Clinical significance of low levels of minimal residual disease at the end of remission induction therapy in childhood acute lymphoblastic leukemia. Blood 2010;115:4657-4663

10. Wood BL: Principals of minimal residual disease detection for hematopoietic neoplasms by flow cytometry. Cytometry B Clin Cytom 2016;90:47-53

Special Instructions Library of PDFs including pertinent information and forms related to the test