Monoclonal B lymphocytes with the characteristics of “indolent” chronic lymphocytic leukemia are present in 3.5% of adults with normal blood counts

Non‐CLL‐like monoclonal B‐cell lymphocytosis in the general population: Prevalence and phenotypic/genetic characteristics

“…In line with this, in this study we report among the general population, up to 2% of adults aged >40 years to carry circulating non-CLL-like B-cell clones in PB. Noteworthy, the frequency of non-CLL-like MBL cases here detected is clearly higher than that previously reported by others, who found CD5 À non-CLL-like MBL cases to be present in approximately 1-1.4% of subjects in the general population (6,7). Such a higher frequency could be due to the higher sensitivity of the flow cytometry approach used to investigate the presence of B-cell clones in PB, which has also proven to be associated with an …”

“…Although most studies that have been published so far have focused in the analysis of cases presenting with absolute lymphocytosis (2-6), several reports indicate that MBL could be a relatively frequent condition in the general population. In this regard, an overall frequency of between 3.5% and 14% of adults older than 40 years has been reported, depending on the sensitivity of the assay used to detect the B-cell clones and population age (2,(6)(7)(8)(9)(10).…”

“…A more detailed analysis of circulating clonal B-cells typically shows that in most cases their immunophenotype and genetic features largely overlap with those of patients with chronic lymphocytic leukemia (CLL)-CLLlike MBL (2)(3)(4)(5)(6)(7)(8)(9)(10). However, in a smaller fraction of MBL cases, between 1% (6,7) and around 2.5% (9,10), in healthy adults with normal and increased lymphocyte counts, non-CLL-like B-cell clones are also detected.…”

“…Until now, non-CLL like MBL has been arbitrarily divided into two major groups: CD5 þ and CD5 À MBL cases. Although in several reports specific reference is made to the phenotypic and even the cytogenetic characteristics of some MBL cases presenting with lymphocytosis (4,11), little information is provided about non-CLL like B-cell clones in subjects who have MBL and normal Bcell counts (6,7,9,12,13). In addition, limited data exists concerning the outcome of subjects with non-CLL-like MBL either detected in population screening studies (9,13) or during investigation for lymphocytosis (2,4,11).…”

Indicações para início de tratamento na leucemia linfóide crônica

“…2 A conseqüência imediata desta detecção cada vez mais freqüente é, do ponto de vista epidemiológico, uma falsa impressão do aumento da sobrevida para este grupo de pacientes. As conseqüên-cias para o paciente, que eventualmente poderia passar o resto de sua vida sem nenhuma manifestação clínica desta alteração, são a de gerar desconforto emocional sem motivo, mas principalmente a de poder resultar em tratamento desnecessário, como conseqüência de eventual procedimento médico açodado.…”