Researchers affiliated with the Chronic Lymphocytic Leukemia Research Consortium have reported that the presence of the abnormal protein, ZAP 70, is a stronger predictor of aggressive CLL than unmutated immunoglobulin heavy-chain variable region gene (IgVh). The details of this study appeared in the August 25, 2004 edition of the New England Journal of Medicine.
Chronic lymphocytic leukemia (CLL) is an indolent disease that now has many therapeutic options, including “watchful waiting.” However, some patients have aggressive disease and may benefit from early aggressive therapies. In many instances, treatment is delayed until symptoms appear. In this study, researchers looked at the predictive value of ZAP-70, which “is associated with enhanced signaling by the cell-surface immunoglobulin receptor of CLL B cells.” These researchers looked at ZAP-70 levels as determined by flow cytometry in over 300 patients with CLL with a median age of 52 years. They observed that patients with <20% expression of ZAP-70 had a median 10-year survival of approximately 50%, while patients with >20% expression of ZAP-70 had a median survival of less than 5 years. They found ZAP-70 to be more predictive than unmutated IgVh and an easier test to perform. They also stated that “because the expression of ZAP-70 appears to be constant over time, it might be used at the time of diagnosis to identify patients who are at increased risk for early disease progression.”
Comments: ZAP-70 appears to be a useful test for predicting the prognosis of younger patients with CLL. It is of interest that the average age of the patients in this study was only 52 years, which is more than a decade younger than the average patients with newly diagnosed CLL. It would be helpful to perform this test on a more representative sample of patients.
Reference: Rassenti LZ, Huynh L, Toy TL, et al. ZAP-70 compared with immunoglobulin heavy-chain gene mutation status as a predictor of disease progression in chronic lymphocytic leukemia. New England Journal of Medicine. 2004; 351: 893-901.
© 1998-2007 OncoEd.com All Rights Reserved.
These materials may discuss uses and dosages for therapeutic products that have not been approved by the United States Food and Drug Administration. All readers should verify all information and data before administering any drug, therapy or treatment discussed herein. Neither the editors nor the publisher accepts any responsibility for the accuracy of the information or consequences from the use or misuse of the information contained herein.
Patient Home
