Instituto de Biología Molecular y Celular del Cáncer, Centro de Investigación del Cáncer/IBMCC (CSIC-USAL), Salamanca, Spain.
Cytometry B Clin Cytom. 2010;78 Suppl 1:S24-34. doi: 10.1002/cyto.b.20543.
Monoclonal B-cell lymphocytosis (MBL) indicates <5 × 10(9) peripheral blood (PB) clonal B-cells/L in healthy individuals. In most cases, MBL cells show similar phenotypic/genetic features to chronic lymphocytic leukemia cells-CLL-like MBL-but little is known about non-CLL-like MBL.
PB samples from 639 healthy individuals (46% men/54% women) >40 years old (62 ± 13 years) with normal lymphocyte counts (2.1 ± 0.7 × 10(9)/L) were immunophenotyped using high-sensitive flow cytometry, based on 8-color stainings and the screening for >5 × 10(6) total PB leukocytes.
Thirteen subjects (2.0%; 9 males/4 females, aged 73 ± 10 years; absolute lymphocyte count: 2.4 ± 0.8 × 10(9)/L) showed a non-CLL-like clonal B-cell population, whose frequency clearly increased with age: 0.4%, 3%, and 5.4% of subjects aged 40-59, 60-79, and ≥80 years, respectively. One single B-cell clone was detected in 9/13 cases, while two B-cell clones were found in 4/13 (n = 17 MBL populations). Nine MBL cell populations showed a CD5(-) phenotype (usually overlapping with marginal zone-derived (MZL) or lymphoplasmacytic (LPL) non-Hodgkin lymphoma (NHL) B-cells, or an unclassifiable NHL), but CD5(-/+d) (n = 3) and CD5(+) (n = 3 non-CLL-like MBL, consistent with a mantle-cell lymphoma (MCL)-like phenotype, and n = 2 CLL-like) MBL were also identified; iFISH supported the diagnosis in most cases. No preferential IGHV usage of B-cell receptor could be found. Twelve cases reevaluated at month +12 showed circulating clonal B-cells, at mean levels significantly higher than those initially detected.
Non-CLL-like MBL cases frequently show biclonality, in association with MZL-, LPL-, MCL-like, or unclassifiable phenotypic profiles. As with CLL-like MBL, the frequency of non-CLL-like MBL increases with age, with a clear predominance of males.
单克隆 B 细胞淋巴增生症（MBL）是指健康个体外周血（PB）中克隆性 B 细胞<5×10(9)/L。在大多数情况下，MBL 细胞表现出与慢性淋巴细胞白血病细胞（CLL 样 MBL）相似的表型/遗传学特征，但对非 CLL 样 MBL 知之甚少。
对 639 名年龄>40 岁（62±13 岁）、淋巴细胞计数正常（2.1±0.7×10(9)/L）的健康个体的 PB 样本进行免疫表型分析，采用高敏感流式细胞术，基于 8 色染色，并筛选出>5×10(6)个总 PB 白细胞。
13 例（2.0%；9 男/4 女，年龄 73±10 岁；绝对淋巴细胞计数：2.4±0.8×10(9)/L）表现出非 CLL 样克隆性 B 细胞群体，其频率随年龄明显增加：40-59 岁、60-79 岁和≥80 岁的受试者分别为 0.4%、3%和 5.4%。9/13 例检测到单个 B 细胞克隆，4/13 例发现 2 个 B 细胞克隆（n=17 MBL 群体）。9 个 MBL 细胞群表现为 CD5(-)表型（通常与边缘区衍生（MZL）或淋巴浆细胞（LPL）非霍奇金淋巴瘤（NHL）B 细胞重叠，或无法分类的 NHL），但也发现了 CD5(-/+d)（n=3）和 CD5(+)（n=3 例非 CLL 样 MBL，符合套细胞淋巴瘤（MCL）样表型，n=2 例 CLL 样）MBL；荧光原位杂交（iFISH）在大多数病例中支持诊断。未发现 B 细胞受体的 IGHV 偏好性使用。12 例在+12 个月时重新评估的病例显示循环克隆性 B 细胞，其水平明显高于最初检测到的水平。
非 CLL 样 MBL 病例常表现为双克隆性，与 MZL、LPL、MCL 样或无法分类的表型谱相关。与 CLL 样 MBL 一样，非 CLL 样 MBL 的频率随年龄增加而增加，且男性明显居多。
