Marianini Pauline, Lacheretz-Szablewski Vanessa, Almeras Marion, Moreaux Jérôme, Bret Caroline
Department of Biological Hematology, St Eloi Hospital, Montpellier University Hospital, Montpellier, France.
Department of Pathology and Onco-Biology, Gui de Chauliac Hospital, Montpellier University Hospital, Montpellier, France.
Cytometry B Clin Cytom. 2024 Nov;106(6):448-464. doi: 10.1002/cyto.b.22208. Epub 2024 Sep 19.
High-grade B-cell lymphomas (HGBCL) represent a heterogeneous group of very rare mature B-cell lymphomas. The 4th revised edition of the WHO Classification of Tumors of Hematopoietic and Lymphoid Tissues (WHO-HAEM) previously defined two categories of HGBCL: the so-called double-hit (DHL) and triple-hit (THL) lymphomas, which were related to forms harboring MYC and BCL2 and/or BCL6 rearrangements, and HGBCL, NOS (not otherwise specified), corresponding to entities with intermediate characteristics between diffuse large B-cell lymphoma (DLBCL) and Burkitt lymphoma (BL), without rearrangement of the MYC and BCL2, and/or BCL6 genes. In the 5th edition of the WHO-HAEM, DHL with MYC and BCL2 rearrangements or THL were reassigned as DLBCL/HGBCL with MYC and BCL2 rearrangements (DLBCL/HGBL-MYC/BCL2), whereas the category HGBCL, NOS remains unchanged. Characterized by an aggressive clinical presentation and a poor prognosis, HGBCL is often diagnosed at an advanced, widespread stage, leading to potential disseminated forms with a leukemic presentation, or spreading to the bone marrow (BM) or other biological fluids. Flow cytometric immunophenotypic study of these disseminated cells can provide a rapid method to identify HGBCL. However, due to the scarcity of cases, only limited data about the immunophenotypic features of HGBCL by multiparametric flow cytometry are available. In addition, identification of HGBCL cells by this technique may be challenging due to clinical, pathological, and biological features that can overlap with other distinct lymphoid malignancies, including Burkitt lymphoma (BL), diffuse large B-cell lymphoma (DLBCL), and even B acute lymphoblastic leukemia (B-ALL). In this study, we aimed to characterize the detailed immunophenotypic portrait of HGBCL, evaluating by multiparametric flow cytometry (MFC) the expression of 26 markers on biological samples obtained from a cohort of 10 newly-diagnosed cases and comparing their level of expression with normal peripheral blood (PB) B lymphocytes (n = 10 samples), tumoral cells from patients diagnosed with B-ALL (n = 30), BL (n = 13), or DLBCL (n = 22). We then proposed a new and simple approach to rapidly distinguish disseminated forms of HGBCL, BL, and DLBCL, using the combination of MFC data for CD38, BCL2, and CD39, the three most discriminative markers explored in this study. We finally confirmed the utility of the scoring system previously proposed by Khanlari to distinguish HGBCL cells from B lymphoblasts of B-ALL. In conclusion, we described a distinct immunophenotypic portrait of HGBCL cells and proposed a strategy to differentiate these cells from other aggressive B lymphoma entities in biological samples.
高级别B细胞淋巴瘤（HGBCL）是一组异质性很强的非常罕见的成熟B细胞淋巴瘤。世界卫生组织造血与淋巴组织肿瘤分类（WHO-HAEM）第4版先前定义了两类HGBCL：所谓的双打击（DHL）和三打击（THL）淋巴瘤，它们与携带MYC和BCL2和/或BCL6重排的形式相关，以及HGBCL，NOS（未另行指定），对应于弥漫性大B细胞淋巴瘤（DLBCL）和伯基特淋巴瘤（BL）之间具有中间特征的实体，且无MYC和BCL2和/或BCL6基因重排。在WHO-HAEM第5版中，具有MYC和BCL2重排的DHL或THL被重新归类为具有MYC和BCL2重排的DLBCL/HGBCL（DLBCL/HGBL-MYC/BCL2），而HGBCL，NOS类别保持不变。HGBCL以侵袭性临床表现和不良预后为特征，常于疾病晚期、广泛播散阶段被诊断，可导致潜在的白血病样播散形式，或扩散至骨髓（BM）或其他生物体液。对这些播散细胞进行流式细胞术免疫表型研究可提供一种快速识别HGBCL的方法。然而，由于病例稀缺，关于HGBCL通过多参数流式细胞术的免疫表型特征的可用数据有限。此外，由于临床、病理和生物学特征可能与其他不同的淋巴恶性肿瘤重叠，包括伯基特淋巴瘤（BL）、弥漫性大B细胞淋巴瘤（DLBCL），甚至B急性淋巴细胞白血病（B-ALL），通过该技术识别HGBCL细胞可能具有挑战性。在本研究中，我们旨在描绘HGBCL详细的免疫表型特征，通过多参数流式细胞术（MFC）评估从10例新诊断病例队列中获得的生物样本上26种标志物的表达，并将其表达水平与正常外周血（PB）B淋巴细胞（n = 10个样本）、诊断为B-ALL（n = 30）、BL（n = 13）或DLBCL（n = 22）患者的肿瘤细胞进行比较。然后，我们提出了一种新的简单方法，利用本研究中探索的三个最具鉴别力的标志物CD38、BCL2和CD39的MFC数据组合，快速区分HGBCL、BL和DLBCL的播散形式。我们最终证实了Khanlari先前提出的评分系统在区分HGBCL细胞与B-ALL的B淋巴母细胞方面的实用性。总之，我们描述了HGBCL细胞独特的免疫表型特征，并提出了一种在生物样本中将这些细胞与其他侵袭性B淋巴瘤实体区分开来的策略。
