Prospective Collection of Biological Data of Prognostic Relevance in Patients With B-Cell Chronic Lymphocytic Leukemia

Inclusion Criteria: * Established diagnosis of B-CLL by NCI criteria, performed by local haematologist. (Diagnosis will be confirmed by the biological review committee according to flow cytometry analysis (positive clusters of differentiation antigen 5 (CD5), 19 (CD19),23 (CD23)). * Age \> 18 years and \< 70 years. * Eastern Cooperative Oncology Group (ECOG)\<=2. * Binet stage A. * Diagnosis performed within 12 months before inclusion in the study. * Patients who do not necessitate therapy by NCI guidelines (watch and wait policy). * Shipment of peripheral blood sample to centralized laboratory for biological assessment. * Clinical data including baseline information on disease localization and laboratory parameters at staging and assurance of follow up updating for at least 3 years are requested. * Written informed consent. Exclusion Criteria: * Patients with CLL whose diagnosis exceed 12 months before registration. * Patients with leukemic phase of lymphoproliferative disorders of B origin CD5- and/or CD23- according to flow cytometry analysis. * Clinical Binet stage B or C. * Patients who necessitate therapy according to NCI guide-lines (no watch and wait policy). * Age \> 70 years. * Without a written informed consent.