title: Monoclonal B-cell lymphocytosis in individuals from sporadic (non-familial) chronic lymphocytic leukemia families persists over time, but does not progress to chronic B-cell lymphoproliferative diseases.
abstract: BACKGROUND
  Monoclonal B-cell lymphocytosis is classified as 'high-count or clinical' monoclonal B-cell lymphocytosis and 'low-count or population' monoclonal B-cell lymphocytosis. Previously, 167 first-degree relatives pertaining to sporadic (non-familial) chronic lymphocytic leukemia families were studied and the presence of seven monoclonal B-cell lymphocytosis individuals was reported.
  
  
  OBJECTIVE
  The aim of this report is to describe the outcomes of five of the original monoclonal B-cell lymphocytosis individuals.
  
  
  METHODS
  Flow cytometry analysis was performed on mononuclear cells previously isolated from peripheral blood samples. A strategy of sequential gating designed to identify the population of CD19(+)/CD5(+) B-lymphocytes was used and, subsequently, the monoclonal B-cell lymphocytosis cells were characterized by the CD20(weak)/CD79b(weak/negative) phenotype.
  
  
  RESULTS
  The monoclonal B-cell lymphocytosis clone showed consistent stability over time with little variations in size. After a median follow-up of 7.6 years, none of the five monoclonal B-cell lymphocytosis individuals progressed to chronic lymphocytic leukemia or other B-cell lymphoproliferative disease.
  
  
  CONCLUSIONS
  The data of this study suggest that chronic lymphocytic leukemia-like monoclonal B-cell lymphocytosis detected in the context of sporadic chronic lymphocytic leukemia families is not prone to clinical evolution and could be just a sign of immune senescence.
authors.affiliation: Universidade de São Paulo (USP), Ribeirão Preto, SP, Brazil. Electronic address: dmazza@usp.br.
authors.forename: Daniel Mazza
authors.initials: DM
authors.lastname: Matos
authors.affiliation: Universidade de São Paulo (USP), Ribeirão Preto, SP, Brazil.
authors.forename: Felipe Magalhães
authors.initials: FM
authors.lastname: Furtado
authors.affiliation: Universidade de São Paulo (USP), Ribeirão Preto, SP, Brazil.
authors.forename: Roberto Passetto
authors.initials: RP
authors.lastname: Falcão
keywords: B cells; Chronic lymphocytic leukemia; First-degree relatives; Flow cytometry; Monoclonal B-cell lymphocytosis