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Flow Cytometry Indications

Flow cytometry is an important laboratory technique for immunophenotyping peripheral blood, bone marrow and tissue samples, and is of great potential value in the diagnosis and classification of leukemias and lymphoproliferative disorders. As with other expensive laboratory tests, an attempt should be made to limit utilization of this modality to those situations where it is likely to provide clinically useful information.

Flow cytometry is most likely to be useful in the following situations: classifying acute leukemias, diagnosing and classifying chronic B cell lymphoproliferative disorders, evaluating T cell and natural killer cell lymphoproliferative disorders, and as an ancillary test in the diagnosis of plasma cell dyscrasias. The following table lists specific examples of these indications and a number of situations where the test is not useful in diagnosis or classification, and therefore not recommended. When samples in the latter category are received for flow cytometry, a clinical pathologist may call the referring physician to discuss appropriateness of the test.

Indications for Flow Cytometry

Acute leukemia

• Distinguish acute lymphoblastic leukemia (ALL) from acute myeloid leukemia (AML)
• Immunological classification of ALL
• Distinguish ALL from malignant lymphoma
• Diagnosis of acute megakaryoblastic leukemia

Chronic B Cell Lymphoproliferative Disorders

• Distinguish monoclonal from polyclonal B cell lymphoproliferative disorders
• Determine subtypes of chronic B cell lymphoproliferative disorders
• Identify malignant non-Hodgkin’s lymphoma in bone marrow or peripheral blood
• Distinguish T cell from B cell chronic lymphoproliferative disorders
• Determine immunophenotypic subtypes of chronic T cell lymphoproliferative disorders
• Identify proliferative disorders of natural killer (NK) cells
• Bone marrow analysis for monoclonal gammopathy
• Bone marrow or tissue analysis for plasmacytosis

Plasma cell dyscrasias

• Bone marrow analysis for monoclonal gammopathy
• Bone marrow or tissue analysis for plasmacytosis

Flow Cytometry NOT Indicated

• Hodgkin’s Lymphoma
• Myelodysplastic syndrome without increased blasts
• Chronic myeloproliferative disorder in chronic phase
• Reactive neutrophilia without lymphocytosis
• Peripheral blood and bone marrow samples from same patient
• Separate bilateral bone marrow aspirations

Flow Cytometry Monitoring of Monoclonal Antibody Therapy

Monoclonal antibodies have been used as immunotherapeutic agents against a variety of diseases such as leukemia, lymphoma, breast cancer, Crohn’s disease and rheumatoid arthritis. Rituximab was the first monoclonal antibody introduced for the treatment of patients with relapsed or refractory low grade or follicular B cell non-Hodgkin’s lymphoma. Since then, several more antibodies have been introduced for the treatment of leukemia and lymphoma. The following table contains a listing of these monoclonal antibodies.  

 

 

Flow cytometry analyses include the CD markers listed above on initial diagnosis, to provide baseline information for therapeutic decisions. Monoclonal antibody therapy can then be monitored with a minimum number of relevant CD markers.