title: Clinical progression and outcome of patients with monoclonal B-cell lymphocytosis.
abstract: Monoclonal B-cell lymphocytosis (MBL) is a clonal lymphoproliferation with the immunophenotype of chronic lymphocytic leukemia (CLL) but a B-lymphocyte count of less than 5 x 10(9)/l and no lymphadenopathy, organomegaly, cytopenias or symptoms. We performed a retrospective analysis of patients with MBL (n = 46), Rai stage 0 CLL (n = 112) and Rai stage > or =1 CLL (n = 54). Median follow-up and range was 30 (0.1-120) months for MBL, 60 (0.1-309) months for stage 0 CLL and 54 (0.1-309) months for stage > or =1 CLL. None of the MBL patients required treatment compared with 24 of 112 (21%) stage 0 CLL and 28 of 54 (52%) stage > or =1 CLL patients (p < 0.0003). No MBL underwent aggressive transformation compared with 1 of 112 (0.8%) stage 0 CLL and 6 of 54 (11%) stage > or =1 CLL patients (p < 0.0003). Progression-free survival (PFS) appeared improved in MBL compared to stage 0 CLL, although this did not reach statistical significant (p = 0.07) due to the relatively short follow-up in the MBL group; two year PFS was 97.2% for MBL, 93.1% for stage 0 CLL, and 68% for stage > or =1 CLL patients (p < 0.0001 for stage > or =1 CLL compared with MBL and stage 0 CLL). This is the first study of outcome in MBL which demonstrates that patients have an improved disease course compared to stage 0 CLL patients. Over a median 2.5 years of follow-up, no MBL patients required treatment or died of CLL-related causes.
authors.affiliation: Faculty of Medicine, University of British Columbia, BC, Canada.
authors.forename: Sarah S
authors.initials: SS
authors.lastname: Fung
authors.forename: Kortney L
authors.initials: KL
authors.lastname: Hillier
authors.forename: Chantal S
authors.initials: CS
authors.lastname: Leger
authors.forename: Irwin
authors.initials: I
authors.lastname: Sandhu
authors.forename: Linda M
authors.initials: LM
authors.lastname: Vickars
authors.forename: Paul F
authors.initials: PF
authors.lastname: Galbraith
authors.forename: Charles H
authors.initials: CH
authors.lastname: Li
authors.forename: Heather A
authors.initials: HA
authors.lastname: Leitch
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001402:B-Lymphocytes / Q000473:pathology; D018450:Disease Progression; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000175:diagnosis / Q000401:mortality / Q000628:therapy; D008218:Lymphocytosis / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D016019:Survival Analysis