Chronic lymphocytic leukemia. B-cell chronic lymphocytic leukemia (B-CLL) is the most prevalent leukemia in the Western Hemisphere, accounting for ~25% of all leukemia's. It represents a monoclonal expansion of small, long-lived, apparently slowly dividing CD5+ B cells. Because of the low proliferative index and a presumed uniform proliferative rate of B-CLL cells in vivo (a fact not yet tested or documented), B-CLL appears to be primarily a disease of accumulation rather than proliferation.~B-CLL remains an incurable illness and there is no survival benefit to early intervention.~Therefore, patients with early stage disease are usually followed closely without initiating treatment. Patients with more extensive disease or progressive cytopenias are eventually treated with cytotoxic agents, with or without prednisone, or with nucleoside analogues that promote apoptosis in the leukemic cells. The clinical outcome of the disease is determined both by the profound dysregulation of the immune system that results in infection and autoimmunity and by leukemic infiltration and destruction of organs. Autoimmune phenomena are common and frequently directed against hematopoietic cells, resulting in autoimmune hemolytic anemia (10-25%) or immune thrombocytopenia.
Chronic lymphocytic leukemia. B-cell chronic lymphocytic leukemia (B-CLL) is the most prevalent leukemia in the Western Hemisphere, accounting for ~25% of all leukemia's. It represents a monoclonal expansion of small, long-lived, apparently slowly dividing CD5+ B cells. Because of the low proliferative index and a presumed uniform proliferative rate of B-CLL cells in vivo (a fact not yet tested or documented), B-CLL appears to be primarily a disease of accumulation rather than proliferation.