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.