The prognosis of clinical monoclonal B cell lymphocytosis differs from prognosis of Rai 0 chronic lymphocytic leukaemia and is recapitulated by biological risk factors.
Monoclonal B-cell lymphocytosis (MBL) is an asymptomatic monoclonal expansion of <5.0 x 10(9)/l circulating CLL-phenotype B-cells. The relationship between MBL and Rai 0 CLL, as well as the impact of biological risk factors on MBL prognosis, are unknown. Out of 460 B-cell expansions with CLL-phenotype, 123 clinical MBL (cMBL) were compared to 154 Rai 0 CLL according to clinical and biological profile and outcome. cMBL had better humoral immune capacity and lower infection risk, lower prevalence of del11q22-q23/del17p13 and TP53 mutations, slower lymphocyte doubling time, and longer treatment-free survival. Also, cMBL diagnosis was a protective factor for treatment risk. Despite these favourable features, all cMBL were projected to progress, and lymphocytes <1.2 x 10(9)/l and >3.7 x 10(9)/l were the best thresholds predicting the lowest and highest risk of progression to CLL. Although IGHV status, CD38 and CD49d expression, and fluorescence in situ hybridization (FISH) karyotype individually predicted treatment-free survival, multivariate analysis identified the presence of +12 or del17p13 as the sole independent predictor of treatment requirement in cMBL (Hazard ratio: 5.39, 95% confidence interval 1.98-14.44, P = 0.001). Overall, these data showed that cMBL has a more favourable clinical course than Rai 0 CLL. Given that the biological profile can predict treatment requirement, stratification based on biological prognosticators may be helpful for cMBL management.
Division of Haematology, Department of Clinical and Experimental Medicine and BRMA, Amedeo Avogadro University of Eastern Piedmont and Azienda Ospedaliero-Universitaria Maggiore della Carità, Novara, Italy. rossidav@med.unipmn.it
Davide
D
Rossi
Elisa
E
Sozzi
Alessia
A
Puma
Lorenzo
L
De Paoli
Silvia
S
Rasi
Valeria
V
Spina
Alessandro
A
Gozzetti
Maristella
M
Tassi
Emanuele
E
Cencini
Donatella
D
Raspadori
Valeria
V
Pinto
Francesco
F
Bertoni
Valter
V
Gattei
Francesco
F
Lauria
Gianluca
G
Gaidano
Francesco
F
Forconi
D000368:Aged; D001402:B-Lymphocytes; D014408:Biomarkers, Tumor / Q000032:analysis; D022801:Complementarity Determining Regions / Q000235:genetics; D018450:Disease Progression; D018572:Disease-Free Survival; D005260:Female; D005434:Flow Cytometry / Q000379:methods; D005500:Follow-Up Studies; D017353:Gene Deletion; D015321:Gene Rearrangement; D016158:Genes, p53; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D007135:Immunoglobulin Variable Region / Q000235:genetics; D017404:In Situ Hybridization, Fluorescence / Q000379:methods; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000235:genetics / Q000276:immunology / Q000401:mortality; D008218:Lymphocytosis / Q000235:genetics / Q000276:immunology / Q000401:mortality; D008297:Male; D008875:Middle Aged; D005810:Multigene Family; D009154:Mutation; D011379:Prognosis; D016016:Proportional Hazards Models; D015996:Survival Rate
D014408:Biomarkers, Tumor; D022801:Complementarity Determining Regions; D007143:Immunoglobulin Heavy Chains; D007135:Immunoglobulin Variable Region