Alert : The site is undergoing maintenance. Some functionality including sign-in may be impacted
Ordering can continue through fax and phone.
Contact us
Contact us
See More
In leukemia, the immature or abnormal cells undergo uncontrolled expansion, resulting in an overproduction of these white blood cells and frequently, the inability to produce enough red blood cells and platelets. In the case of acute leukemias, the normal differentiation pathway is blocked at a stage where the cells are still proliferating but do not move into terminal differentiation. According to the 2018 GLOBOCAN survey, cases of leukemia are on the rise worldwide: 437,033 new cases of leukemia were registered with a global incidence rate of 5.2 and a mortality rate of 3.5 (ASR per 100,000).1 Based on the progenitor cell in the bone marrow, leukemia can be lymphocytic or myelocytic. Lymphocytic (lymphoblastic) leukemia arises from T or B lymphocytic progenitors whereas non-lymphocytic or myeloid leukemia arises from progenitors of erythrocytes, granulocytes, monocytes or platelets.1
Leukemia is caused by genetic and metabolic alterations in lymphocyte or myeloid progenitors in the bone marrow. Environmental and lifestyle risks factors of leukemia include smoking, indoor and outdoor air pollution, exposure to radiation and certain chemicals, radiation therapy, chemotherapy and some genetic disorders such as Down Syndrome.2
Leukemia is categorized as acute or chronic based on the rate of proliferation of the leukemic cells. There are four major types of leukemia, two each for the predominant cell lineages—chronic/acute myeloid leukemia (CML and AML) and chronic/acute lymphocytic leukemia (CLL, ALL).3 Cases of cancer and leukemia are on the rise worldwide. In 20 years (1998 to 2018) cases of all types of leukemia significantly increased to 187% for CLL, 108% for AML, 96% for CML and 92% for ALL.1,4
Leukemia is a complex multifactorial disease and diagnosis requires an interdisciplinary approach, including review of symptoms and physical examination, blood tests, bone marrow biopsy, cerebrospinal fluid (CSF) evaluation, radiology and genetic testing. Flow cytometry proves to be an important tool integral to leukemia diagnosis.
The type of leukemia can also be determined by analyzing the phenotype of peripheral leukemic cells by flow cytometry using specific markers such as ZAP-70 and CD38.5 A flow cytometry analysis of cerebrospinal fluid (CSF) revealing high numbers of mononuclear cells or atypical infiltrates will indicate extramedullary spread of the leukemia and CNS involvement.5,6
Flow cytometry has been reported to be an invaluable tool both to aid in in diagnosis as well as monitoring of the disease.5
Flow cytometry offers a commonly used method to discriminate between myeloid and lymphoid blasts.5
Under homeostatic conditions, blast counts in the bone marrow or peripheral blood account for less than 5% of cells. Increased blast count is a cause for concern and warrants further investigation. In AML, aberrations can be found in counts and phenotype of blasts.
The diagnosis of CLL relies on morphological analysis and immunophenotyping. Based on WHO diagnostic criteria, immunophenotyping of typical CLL demonstrates weak expression of CD20 with co-expression of CD5, CD19 and CD23 on the neoplastic B cells (with consistent counts of 5,000 circulating neoblasts/mL in the peripheral blood during a 3-month period).8 Some markers, such as CD5, CD19, CD23, weak CD20 and immunoglobulin kappa/lambda, are used with consensus in routine diagnostics and are considered required in screening panels. Other markers are recommended as they can provide additional information to better characterize neoplastic B cells or are of prognostic value e.g., weak CD79b, CD81 or CD38, CD45.8
Flow cytometry has been reported to be a sensitive method with which to detect residual disease in chronic leukemia. Using sequential gating strategies, multiple markers, such as CD5+, CD19+ CLL, can be monitored simultaneously. Marker expression between normal and neoplastic cells can also be discriminated.8
The classification criteria from both the WHO and European Group for the Immunological Characterization of Leukemias (EGIL) offer specific lineage markers that can be used to identify the types of leukemia by flow cytometry.8 Myeloid blasts are positive for cytoplasmic myeloperoxidase (cyMPO) and CD117 while lymphoid blasts can be confirmed with cytoplasmic CD79a (cyCD79a) or cytoplasmic CD3 positivity.7
Flow cytometry panels used for sub-grouping of leukemia depend on the cell lineages to be investigated.7
Minimal residual disease (MRD) is a state where patients still carry small counts of leukemic cells during and after therapy. These cells can be the source of future recurrence, and monitoring MRD is essential for therapy adjustments, such as to escalate or decrease therapy doses, to determine qualification for transplantation, and to inform the therapy outcome. The prognostic utility of multicolor flow cytometry for assessing MRD in patients with acute lymphoblastic leukemia and in acute myeloid leukaemia has been established.13 MRD negativity assessment is considered a positive predictor of good long-term prognosis in multiple myeloma as well.14
Flow cytometry facilitates the phenotypic characterization of leukemic cells and allows the monitoring of MRD. Sets of fluorescently labeled monoclonal antibodies can be used in polychromatic flow cytometry to run panels of markers identifying MRD.5,11 Flow cytometry is used as a tool to monitor MRD in AML patients as PCR monitoring of fusion transcript amplification is only relevant in a fraction of patients. Standardized quantitative flow cytometry protocols can be used during MRD assessment with panels ranging from three to eight colors.13, 14 MRD values greater than 0.01% (1 MRD cell/10,000 bone marrow cells in a bone marrow aspirate) are associated with high risk of relapse and poor survival.15 Flow cytometry can concurrently elucidate the phenotype and functionality of morphologically ambiguous cells.
Our large portfolio of single-color antibody CE-IVD reagents span across a range of specificities and dyes to help in the characterization of hematologic neoplasia. These panels are to be verified and validated by the lab.
Furthermore, BD Biosciences provides the BD OneFlow™ Solution, comprising a comprehensive set of reagents, setup beads, protocols and assay templates, to help standardize leukemia and lymphoma immunophenotyping. This can improve laboratory efficiency and enable reliability and accuracy of results.16,17
BD OneFlow™ products and BD single-color antibody reagents are Research Use Only.
