Erythropoietin and chronic lymphocytic leukemia.

Anemia is a frequent clinical feature with adverse prognostic effects in patients with chronic lymphocytic leukemia (CLL). It may complicate CLL at any time during the course of the disease. Different factors concur to the occurrence of anemia in CLL, as in other lymphoproliferative diseases: leukemic bone marrow infiltration, the myelosuppressive effect of chemotherapy and inhibiting cytokines, autoimmune phenomena, hypersplenism, a poor nutritional status that leads to folic acid, vitamin B12 and iron deficiency. In addition, a defective endogenous erythropoietin (EPO) production has also been described in patients with lymphoproliferative diseases. The severity of anemia, which may be worsened by an impaired cardiopulmonary function, may profoundly compromise the patients' quality of life and, indirectly, the outcome of cancer bearing patients. Several Authors have reported the clinical activity of recombinant human (rHu)EPO in anemic patients with lymphoproliferative diseases, including CLL. Low serum EPO levels at baseline and EPO levels inappropriately low for the degree of anemia help to identify patients who are likely to respond to EPO. A clear dose-dependent response to EPO has been reported by different Authors and it has been suggested that 5,000 IU should be considered as an appropriate initial dose for the majority of patients. rHuEPO represents a potentially effective and safe therapy for the management of anemia associated with lymphoproliferative diseases. The reduction of red blood cell transfusion requirement, the improvement of quality of life through the remission of fatigue-related anemia are two important results that should be considered in the management of patients with CLL. In prospect, the availability of new rHuEPO molecules with a more prolonged half-life may open new therapeutic avenues.