CLL Monitoring, MRD Detection, Blood
Confirming the presence or absence of minimal residual disease in patients with known chronic lymphocytic leukemia who are either postchemotherapy or post-bone marrow transplantation
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Chronic lymphocytic leukemia (CLL) is a low-grade, B-cell neoplasm that is the most common leukemia detected in the western world. It is a disease primarily of adults and may present as a lymphocytosis, be detected as part of a lymphadenopathy evaluation, or be found incidentally in an otherwise asymptomatic patient. The diagnosis of CLL is based on a combination of morphologic features showing primarily small lymphoid cells with coarse chromatin and scant cytoplasm and an immunophenotype of clonal B-cells with dim immunoglobulin, dim CD20, and coexpression of CD5 and CD23.
New therapeutic approaches in CLL have been increasingly successful with some patients showing no or only very minimal residual disease (MRD) in their peripheral blood or bone marrow specimens following a therapeutic course. Immunophenotyping studies are necessary as morphologic features are not sufficient to detect MRD. The absence of MRD is an important prognostic indicator in these patients.
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.
An interpretive report for presence or absence of minimal residual disease (MRD) for chronic lymphocytic leukemia (CLL) is provided.
Individuals without CLL should not have detectable clonal B cells in the peripheral blood or bone marrow.
Patients who have detectable MRD by this assay are considered to have residual CLL disease.
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 chronic lymphocytic leukemia.
This assay has been used in several clinical trials at Mayo Clinic evaluating response to therapies in chronic lymphocytic leukemia (CLL). In total, 421 specimens have been analyzed for CLL minimal residual disease (MRD) with this assay; 316 had MRD present and 105 had no detectable MRD. Of the 316 with MRD, 136 had <1.0% MRD with 18 at 0.01% detectable MRD (assay sensitivity). Of the 136, 123 had direct correlations with the routine clinical flow cytometric screening assay. Of those 123 cases, 63 had similar findings by both techniques, while 60 had detectable clonal B cells only with the CLL MRD assay.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Hallek M, Cheson BD, Catovsky D, et al: Guidelines for the diagnosis and treatment of chronic lymphocytic leukemia: a report from the International Workshop on chronic lymphocytic leukemia updating the National Cancer Institute-Working Group 1996 guidelines. Blood 2008;111:5446-5456
2. Varghese AM, Rawstron AC, Hillmen P: Eradicating minimal residual disease in chronic lymphocytic leukemia: should this be the goal of treatment? Curr Hematol Malig Rep 2010;5:35-44
3. Shanafelt TD: Predicting clinical outcome in CLL: how and why. Hematology Am Soc Hematol Educ Program 2009;421-429
4. Sayala HA, Rawstron AC, Hillmen P: Minimal residual disease assessment in chronic lymphocytic leukaemia. Best Pract Res Clin Haematol 2007;20:499-512
5. Rawstron AC, Villamor N, Ritgen M, et al: International standardized approach for flow cytometric residual disease monitoring in chronic lymphocytic leukaemia. Leukemia 2007;21:956-964
6. Moreton P, Kennedy B, Lucas G, et al: Eradication of minimal residual disease in B-cell chronic lymphocytic leukemia after alemtuzumab therapy is associated with prolonged survival. J Clin Oncol 2005;23:2971-2979