Chronic Lymphocytic Leukemia
Summary of Key Points
• Chronic lymphocytic leukemia (CLL) is the most prevalent type of adult leukemia and is defined by a distinctive immunophenotype of CD19+, CD20+, CD5+, CD23+, and surface immunoglobulin (sIg)-positive cells.
• The environmental or genetic cause of CLL in most patients is not known, although 8% to 10% of patients have a first-degree relative with this diagnosis.
• CLL lacks a single driving mutation that defines the disease, although autonomous B-cell receptor signaling appears to be important; the role of stem cells remains controversial.
• Classic staging for CLL at diagnosis is not helpful in most patients for risk stratification, but new prognostic factors such as immunoglobulin variable heavy chain (IGHV1) mutational status, interphase cytogenetics, β2-microglobulin, and thymidine kinase activity have improved staging of this disease.
• Common disease-related complications associated with CLL include immune deficiency with associated infections, autoimmune complications, secondary cancers, and Richter transformation.
• CLL is treated only when it becomes symptomatic, based on earlier studies showing no survival advantage to early intervention. This same approach is followed for all patients irrespective of genetic risk.
• The current standard treatment for young and older patients with CLL is chemotherapy combined with an anti-CD20 monoclonal antibody. Although this prolongs survival in CLL, it does not cure the disease.
• Reduced-intensity allogeneic stem cell transplant is curative in a subset of CLL patients but still carries with it treatment-related morbidity and mortality.
• B-cell receptor antagonists offer great promise as a new targeted therapy for CLL.
1. A 50-year-old patient was recently seen by his primary care physician and noted to have leukocytosis with a predominate mature lymphoid differential. Immune phenotype was performed on these cells showing CD19, CD5, CD20, CD23+ with surface immunoglobulin dimly positive. He is referred for initial consultation, where he lacks symptoms of disease or abnormal findings on physical examination. Which of the following tests or interventions is least helpful in his initial evaluation?
