NCCN Guidelines for Patients® | Chronic Lymphocytic Leukemia

12 NCCN Guidelines for Patients ® : Chronic Lymphocytic Leukemia, 2018 1 Chronic lymphocytic leukemia First tests for CLL For diagnosis, B-cells should also be tested for which proteins are in the cells’ surface (membrane). See Figure 5. This is called immunophenotyping (flow cytometry). If there are fewer than 5,000 monoclonal B-cells, no enlarged lymph nodes, and no other signs of CLL, you may have MBL ( m onoclonal B - l ymphocytosis). MBL is common, especially among older adults. It is not cancer and very few people with MBL develop CLL. The recommended care for MBL is observation. Observation or “watch and wait” is a period of testing to watch for changes in status. Some people won’t need treatment for years if at all. A common test of cells is IHC ( i mmuno h isto c hemistry). This method involves applying a chemical marker to cells and looking at them with a microscope. Flow cytometry is a newer method by which some cell tests can be done. Flow cytometry can be used to count B-cells, confirm clonality, and do immunophenotyping. This method involves first adding a marker—a light-sensitive dye—to cells. Then, your blood will be passed through a flow cytometry machine. The machine measures surface proteins on thousands of cells. Flow cytometry is commonly used to diagnose CLL. When being tested for CLL, mantle cell lymphoma needs to be ruled out. Mantle cell is a closely related type of blood cancer. This cancer has high levels of the protein called cyclin D1. There is too much cyclin D1 because of abnormal chromosomes in cells. To rule out mantle cell lymphoma, your blood may be tested with a cytospin machine for cyclin D1. Another test option is FISH ( f luorescence i n s itu h ybridization) to test for abnormal chromosomes. Most often, flow cytometry on a blood sample can be used to diagnosis CLL. However, for some people, another method is needed. In these cases, a biopsy of your lymph nodes is advised. A biopsy removes tissue samples to test for cancer. You will need anesthesia to numb the site. Then, part or all of one or more lymph nodes will be removed through a cut made in your skin. B-cells from the removed nodes will be tested with an IHC panel for the immunophenotype. The panel should include testing for CD3, CD5, CD10, CD20, CD23, and cyclin D1 proteins. Figure 5 CD20 protein CLL cells have a common pattern of proteins in their membrane. This pattern includes the presence of CD5, CD19, and CD23 proteins, some CD20, and no CD10 proteins. Immunophenotyping is the process of identifying the proteins in cells’ membranes. Derivative work of Rituximab Binding to CD20 on a B Cell Surface by NIAID available at Rituxima_Binding_ to_CD20_on_a_B_Cell_Surface_(6830897205).jpg under a Creative Commons Attribution 2.0 Generic license