most common leukemia worldwide; ~2/10k; patients are usually > 50 yo; male > female, 2:1
95-98% are B-cell in origin and monoclonal; neoplastic cells appear as normal small lymphocytes
display normal surface Ig, CD19, CD20; also CD5 which is normally a T-cell marker (expressed on some B)
most are memory B-cell or virgin B-cell (virgin marked by CD38)
50% of CLL cells display chromosomal abnormalities (trisomy 12 and 13 are the most common)
most have high levels of bcl-2, which is a blocker of apoptosis
may infiltrate the bone marrow, lymph nodes, liver, spleen; symptoms include: fever, sweats, malaise, weight loss
also leads to altered immune function: hypogamaglobulinemia; hypersensitivity (i.e. to insect bites); autoimmune hemolytic anemia (10% of patients); immune thrombocytopenia (1-2% of patients)
(except for rare cures in children with bone marrow transplant)
remission can be induced by chemotherapy: alkalating agents-chlorambucil (oral), cyclophosphamide (oral or IV);
corticosteroids; purine analogs - fludarabine
radiation can reduce local symptoms due to mass effect
interferons or antibodies directed at CLL cells are current areas of research
supportive care is crucial (transfusion, antibiotics, etc)
may transform into a more aggressive lymphoid neoplasm:
large cell lymphoma
(Richter's syndrome)
acute lymphoblastic leukemia
- very rare
Prolymphocytic leukemia
: variant of CLL, more aggressive clinical course (survival is typically 4-10 mos); cells are larger, more atypical appearing, have more surface Ig than B-CLL cells