[Chronic lymphocytic leukemia--the old and the new]

Chronic Lymphocytic Leukemia (CLL) is the most frequent lymphoproliferative disease and leukaemia in western countries. CLL occurs more frequently in men than women, the median age at diagnosis is 65 years. CLL is defined as a persisting chronic lymphocytosis > 5 G/l with classical morphological features (small lymphocytic cells with round nuclei, dense chromatin and small cytoplasmic rim) and a classical immunophenotype (CD5+, CD19+, CD20+, CD23+); however, deviations from classical morphology are frequent. In cases with classical diagnostic features in the peripheral blood, a bone marrow biopsy is not necessary for diagnosis. Prognostic features comprise the stage of the disease according to the Rai or Binet systems, laboratory markers such as LDH, beta-2-microglobulin, lymphocyte doubling time and CD38 expression by flow cytometry (and ZAP-70 expression if available) as well as the status on IgV(H) hypermutations and cytogenetic analysis. Up to 2/3 of patients do not need treatment at the time of diagnosis and can initially be followed using a watch and wait strategy. If therapy becomes necessary, initial standard treatment still is chlorambucil. Later, purine analogues and Alemtuzumab are treatment options for refractory or relapsing disease. Therapies with antibodies such as Alemtuzumab and Rituximab in combination with purine analogues are currently under clinical investigation. With recurrent or atypical infections, hypogammaglobulinemia should be searched for and immunoglobulins should be substituted if necessary. However, their prophylactic use is not recommended.